Report on zoonoses and zoonotic agents in Austria 2012

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REPORT ON ZOONOSES AND ZOONOTIC AGENTS IN AUSTRIA, 2012 Federal Ministry of Health (FMH) Austrian Agency for Health and Food Safety (AGES)


LIST OF AUTHORS

CONTENTS

Dr. Peter Much

Priv.-Doz. Dr. Pamela Rendi-Wagner

LIST OF ABBREVIATIONS 4

AGES – Austrian Agency for Health and Food Safety Data, Statistics & Risk Assessment

Federal Ministry of Health Head of Section III Public Health and Medical Affairs

FOREWORD 5

1220 Vienna, Spargelfeldstraße 191 Tel.: +43 (0) 664 8398065 Fax: +43 (0) 50 555 95 37303 E-mail: zoonosenbroschuere@ages.at Homepage: www.ages.at

1030 Vienna, Radetzkystraße 2 Tel.: +43 (0) 1 711 00-4637 Fax: +43 (0) 1 713 4404-1100 E-mail: pamela.rendi-wagner@bmg.gv.at Homepage: www.bmg.gv.at Dr. Ulrich Herzog Federal Ministry of Health Head Division II/B Consumer Health and Health Prevention Division 1030 Vienna, Radetzkystraße 2 Tel.: +43 (0) 1 711 00-4824 Fax: +43 (0) 1 710 4151 E-mail: ulrich.herzog@bmg.gv.at Homepage: www.bmg.gv.at

INTRODUCTION 6 CONTROL OF ZOONOTIC AGENTS IN AUSTRIA 8 ZOONOSES AND ZOONOTIC AGENTS SUBJECT TO MANDATORY SURVEILLANCE IN AUSTRIA 11 SALMONELLOSIS

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CAMPYLOBACTERIOSIS 16 BRUCELLOSIS 19 LISTERIOSIS 22 TRICHINELLOSIS 25 ECHINOCOCCOSIS 27 TUBERCULOSIS DUE TO MYCOBACTERIUM BOVIS

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VEROCYTOTOXIGENIC ESCHERICHIA COLI (VTEC)

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TOXOPLASMOSIS 38 FOOD-BORNE OUTBREAKS IN AUSTRIA 42 LIST OF NATIONAL REFERENCE CENTRES AND NATIONAL REFERENCE LABORATORIES INCLUDING CONTACT PERSONS 46

ACKNOWLEDGEMENT The authors wish to thank all public health officers, veterinarians, food inspectors, staff members of the institutes of human and veterinary medicine, and staff members of the food and feeding stuff laboratories for collecting and making available to us the data used to produce this report.

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LIST OF ABBREVIATIONS

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AGES AURES B. C. CDC CPE DT ECDC EFSA EMS ESBL EU EWRS FMH HUS L. FBO

Austrian Agency for Health and Food Safety Austrian Resistance Report Brucella Campylobacter Centers for Disease Control and Prevention carbapenemase producing enterobacteria definitive type European Centre for Disease Prevention and Control European Food Safety Authority epidemiological reporting system extended-spectrum ß-lactamase-producing Enterobacteriaceae European Union Early Warning and Response System Federal Ministry of Health Haemolytic-Uraemic Syndrome Listeria food-borne outbreak

M. MRSA NRL NRC OBF OBMF OIE OTF PT S. SARS T. VTEC WHO °C

Mycobacterium methicillin-resistant Staphylococcus aureus national reference laboratory national reference centre officially brucellosis free officially Brucella melitensis free World Organisation for Animal Health officially tuberculosis free phage type Salmonella Severe Acute Respiratory Syndrome Toxoplasma Verocytotoxigenic Escherichia coli World Health Organization degree Celsius

FOREWORD

Alois Stöger Federal Minister of Health Over the years, measures have been implemented along the food chain to combat the threat of infectious diseases affecting humans and animals in Austria. To further protect human health, intensive efforts have been made to keep animal holdings pathogen-free in order to provide consumers with safer food. With respect to human salmonellosis cases, the success of the control programs is well documented. In 2002, in Austria, 8,405 Salmonella infections were diagnosed bacteriologically. According to the current report on Zoonoses and zoonotic Agents in Austria, only 1,729 salmonellosis cases were reported in 2012, corresponding to an 80 % reduction in cases.

The current zoonoses report presents facts and figures on selected food-borne infectious diseases in humans. In addition, it provides evidence of the occurrence of these pathogens in foodstuffs and in the corresponding productive livestock. This publication is intended to inform all interested parties, in particular consumers, about the most important food-borne zoonoses. Lastly, I would like to express my gratitude to everyone who is engaged in the surveillance and control of zoonoses.

FOREWORD

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INTRODUCTION Zoonoses are infectious diseases transmissible from animals to humans. Transmission may occur by direct contact with infected animals, consumption of contaminated foods (particularly those of animal origin), or indirect contact (e.g. environmental contamination). Infants, the elderly, pregnant women, and individuals with compromised immune system are known to be the most vulnerable to acquiring zoonoses. Austria has a long history of controlling zoonotic agents in livestock. Owing to the successful implementation of surveillance programs, Austria’s farm animals have been officially free of brucellosis and tuberculosis since 1999 and 2001, respectively. Today, human infections caused by the gastrointestinal pathogens Campylobacter and Salmonella are the most prevalent zoonoses and they are mainly contracted by consuming contaminated foods. Combating those pathogens in animals is difficult because they may infect livestock without causing disease. Thus, animals may harbour great numbers of a certain pathogen without actually falling ill. Therefore, unless food is prepared with great care, humans may contract an infection when consuming products derived from or having come in contact with infected animals or their excrements. Targeted programs are conducted to control these pathogens. For example, surveillance programs serve to combat Salmonella in flocks of laying hens, broilers or turkeys, the mainly affected animal populations with these pathogens; monitoring programs are implemented at different stages along the food chain to check for Campylobacter and other pathogens. The successful performance is based on a collaboration of the Federal Ministry of Health (FMH), the provincial Public Health Directorates and the Austrian Agency for Health and Food Safety. In the FMH, Division II, including Department B (Consumer Health and Health Prevention) and their Unit for Veterinary and Food Affairs,

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and Division III (Public Health and Medical Affairs) are among the collaborating parties. The Federal Ministries of Agriculture, Forestry, Environment and Water Management, as well as the local authorities, are involved in these endeavours. The FMH implements programs to survey zoonotic agents in animals and foodstuffs that could harbour and serve as infectious vehicles for pathogens. The program findings are used to develop control strategies such as specific nationwide inspections of the animals’ health status by risk-based or randomized sampling plans. In recent years, new pathogens have emerged, and outbreaks of emerging zoonoses, such as Severe Acute Respiratory Syndrome (SARS, spreading from Asia), Influenza A (H1N1) or the West Nile Virus (in the USA), have caused novel forms of epidemics. Known bacteria may also acquire new pathogenic capacities and cause severe disease. For example, in humans, verocytotoxigenic Escherichia coli (VTEC) strains of the otherwise harmless intestinal inhabitant E. coli have repeatedly caused disorders dominated by bloody diarrhoea and, in rare cases, led to life-threatening Haemolytic Uraemic Syndrome (HUS). In spring 2011, a new variant of E. coli, VTEC O104:H4, caused an outbreak with more than 3,800 cases and 53 fatalities in Germany also affecting other European countries. This new enteroaggregative E. coli strain, which acquired different pathogenic genes (e.g. to produce proteins that adhere to human enterocytes), showed resistance to several critically important antibiotics and the ability to produce verocytotoxin 2. These factors highly increased its virulence. Multi-resistant bacteria – microorganisms resistant to antimicrobial agents from more than three different classes of substances usually effective against the same bacterial species – pose an additional risk to humans. Examples of multi-resistant organisms are

methicillin-resistant Staphylococcus aureus (MRSA), extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae, carbapenemase-producing Enterobacteriaceae, or Salmonella Typhimurium DT104. Data concerning antimicrobial resistance and antimicrobial usage in Austria are published annually in the Austrian Resistance Report (AURES), prepared on behalf of the FMH by the AGES and the National Reference Centre for Antimicrobial Resistance and Nosocomial Infections (Convent Hospital Elisabethinen Linz) (http://bmg. gv.at/home/Schwerpunkte/Krankheiten/Antibiotikaresistenz/ or http://www.ages.at/ages/gesundheit/ mensch/antibiotikaresistenzen/). A food-borne outbreak is defined as an incident affecting two or more persons by a similar illness resulting from the ingestion of a common food or food prepared by the same food handler. The national Zoonosis Act obliges the responsible authorities to investigate those outbreaks and to perform moderate epidemiological and microbiological analyses. In Austria, a decline in human cases has been observed for many zoonotic agents. This is due to the successful control of zoonoses in the animal production, in part by maintaining the official disease-free status for certain epizootics; these facts also reflect the excellent cooperation between veterinarians, farmers and the food industry in combating food-borne zoonoses.

organizations and others were assembled to discuss strategies against Campylobacter in the Austrian broiler production chain and the impact of Campylobacter on human health in Austria. Besides the measures undertaken by food producers and authorities to control zoonoses along the food chain, the consumers also must be involved. As information about incidence of infectious diseases, safe food handling, and the proper preparation of possibly contaminated foodstuffs is available to the public, the consumer also must take responsibility for safe meals. Consumers ask for naturally-produced foodstuffs but also that the product is free of pathogens. Animals can harbour human pathogens without falling ill or showing any symptoms of disease. If all human pathogens are eliminated during food production, as a consequence other microorganisms, such as those needed to mature certain foods or that ensure the unique taste of a certain dish, are also erased. Therefore it is of utmost importance for consumers to properly store and also carefully and appropriately prepare foodstuffs. The present Report on Zoonoses is intended to give a general overview on the occurrence of zoonotic agents in food-producing animals, in foodstuffs, and in humans and also on the incidence of food-borne outbreaks in Austria in 2012.

In the EU and also in Austria, the numbers of campylobacteriosis cases in humans are either increasing or remaining at a high level. Control measures for Campylobacter turned out to be very difficult and complex; in response, a platform called “Campylobacter – a concern to everyone” was launched in June 2012. Experts in the fields of human and veterinary medicine and food, as well as representatives from industry, several authorities, the poultry health service, trade

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CONTROL OF ZOONOTIC AGENTS IN AUSTRIA The surveillance of zoonoses is designed to continuously collect information on the occurrence of zoonotic agents throughout the entire food chain – from the environment to primary production, and food production through to the consumer. Based on this data, measures can be taken to disrupt the chain of pathogenic transmission to protect humans against zoonoses. This Report on Zoonoses 2012 is based on the data collected and compiled for the European Report on Trends and Sources of Zoonoses 2012. The annual zoonoses reports of each European Union member state detail the results of each country’s surveillance activities. The European Food Safety Authority (EFSA), together with European Centre for Disease Prevention and Control (ECDC), collect these reports and prepare The European Union Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents and Foodborne Outbreaks. The compiled report (last version from 2011) can be downloaded from the website of the EFSA: http://www.efsa.europa.eu/en/efsajournal/ pub/3129.htm.

Monitoring programs Monitoring is the continuous collection of health or environmental data to allow changes in the prevalence of infections (percentage of diseased or infected

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individuals in a given population) to be detected at an early stage. Monitoring systems observe, collect, and evaluate data in a repetitive manner to answer specific predefined questions. Sample selection is based on sampling plans developed on the basis of epidemiological requirements, with the time and place of sampling determined randomly. As in previous years, the Department for Animal Health, Trade with Living Animals, and Veterinary Legislation of the Consumer Health and Health Prevention Division of the Federal Ministry of Health (FMH) set up a monitoring program targeting the prevalence of selected pathogens in cattle, sheep, pigs, and broilers and testing the isolated bacteria for their antibiotic susceptibility. The program was implemented throughout Austria by specifically commissioned veterinarians and with the active support of AGES.

Surveillance programs The aim of zoonoses surveillance is to control disease in animal populations, to allow changes in their health status to be detected as early as possible and to take targeted counteractive measures. According to the World Health Organization (WHO), surveillance programs are currently the most important tools to

control food-borne infectious diseases and to combat notifiable animal diseases (e.g., BSE, bovine tuberculosis, and rabies). Based on EU legislation, competent departments of the Ministries of Health and of Agriculture, Forestry, Environment and Water Management initiate surveillance programs in their areas of responsibility – i.e., for both animals and humans, from feeding stuffs to food products.

Austria: officially free of certain epizootics The veterinary Departments of the Consumer Health and Health Prevention Division of the FMH defines, on the basis of national and EU legislation and of specification of the World Organization for Animal Health (OIE), which diseases are to be classified as notifiable epizootics in Austria. Health authorities’ awareness concerning the epizootic situation in Europe and worldwide can result in prompt prophylactic action, including the restriction of live animal trades, to prevent pathogenic spread. At a European level, the trade in livestock and livestock products is strictly regulated. EU member states successful at eradicating certain animal diseases are granted a status referred to as “officially free” of epizootics (e.g., bovine tuberculosis or Brucella melitensis in small ruminants). To keep this status and to fulfill EU requirements, the veterinary agencies of the respective countries are obliged to carry out annual surveillance and control programs. The aim of achieving certified absence of epizootics is to keep Austria’s livestock healthy and to assure trading benefits for Austria’s agriculture.

Cooperation between specialties Identifying emerging or re-emerging infectious’ diseases is a challenging task that requires cooperation between experts of varied disciplines, including human and veterinary medicine, food hygiene, microbiology, and epidemiology. Information exchange at an international level plays an important role in guaranteeing that the surveillance of zoonoses is based on state-ofthe-art science.

National reference centres and and national reference laboratories During the implementation of the network for epidemiological surveillance and the control of communicable diseases in the EU, national reference centres were nominated to manage the most important human pathogens. In the areas of veterinary medicine and food control, national reference laboratories were established. According to the Epidemics Act, the Zoonoses Act, and the Food Safety and Consumer Protection Act, any zoonotic agent isolated from humans, animals, or foods must be sent to the appropriate national reference centre or laboratory for confirmation and typing. The Austrian reference centres and laboratories for specific zoonotic agents, as described in this report, are listed in the annex to this brochure.

Recording data on infectious diseases in humans In the event of a notifiable infectious disease, the

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physician must report the case to the competent municipalities. Case-based data are collected nationwide in the epidemiological reporting system (EMS). If a notifiable agent from a human sample is detected, medical laboratories are also obliged to report the case. Via the EMS, the responsible authorities gain an overview of the situation and, if necessary, act to prevent further spread of the pathogen. A short report is also extracted and compiled using EMS which is published nationwide monthly and yearly by the Federal Ministry of Health (http://bmg. gv.at/home/Schwerpunkte/Krankheiten/Uebertragbare_Krankheiten/Statistiken/).

EU-wide comparison of human cases Infectious disease activity in EU member states can be compared, by looking at the yearly incidence of cases per 100,000 population, although the comparison is limited due to variation in notification procedures for human cases. Some EU member states report incidences far under the EU average; possible explanations include the variation in physician consultation among diarrhoea cases, medical visits that do not result in bacteriological examination of stool samples and medical laboratories that are not required to report the detection of a pathogen to the authorities. This differentiation is, for example, noticeable among tourists returning from a country with low Salmonella incidence when this pathogen is found in much higher frequencies than in the native population. Additionally, in countries that often detect Salmonella in their farm animal population, the observation of improbably low

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human salmonellosis incidences appears unreliable. Under the terms of the EU-wide baseline surveys to investigate the prevalence of zoonotic Salmonella, all member states used the same protocol to sample and bacteriological examine their animal populations. Therefore, the Salmonella prevalence could be directly compared within all member states and some member states with very low incidence of Salmonella in humans were confronted with very high prevalence of Salmonella in their laying hen or broiler population. Nevertheless, the incidence of cases per 100,000 population is a very good indicator to measure trends of cases on a national level over several years.

ZOONOSES AND ZOONOTIC AGENTS SUBJECT TO MANDATORY SURVEILLANCE IN AUSTRIA SALMONELLOSIS Salmonellosis is an infectious disease caused by Salmonella species – motile, rod-shaped bacteria which can affect both animals and humans. In Europe, most human cases of food-borne salmonellosis are caused by the serotypes S. Enteritidis and S. Typhimurium.

Occurence Salmonellosis occurs worldwide, and it has diverse modes of transmission. Farm animals can become infected by eating contaminated feeding stuffs. In poultry, Salmonella infection does not clinically manifest itself and remains unnoticed. As a result, an entire laying hen flock may become permanently asymptomatic carriers capable of transmission. Transmission of the pathogen from an infected laying hen caused by reproductive tract colonization may lead to contaminated eggs, which, unless thoroughly cooked, poses a threat to human health. In environments of high humidity and temperature, the pathogens can also migrate through thin or defective faeces-covered egg shells.

reptiles), wild animals (birds)

Mode of transmission Transmission of Salmonella occurs mainly through consumption of raw or insufficiently heated foods of animal origin (eggs, poultry, meat, and raw milk). Homemade products containing raw eggs, such as tiramisu, mayonnaise, creams, and ice cream, may also be contaminated. Raw or undercooked meats (e.g., poultry, minced meat, or raw sausage) present a risk if, during the food manufacturing process, they are mixed with other products that are not heated prior to consumption (e.g., potato salad). Transmission to other foods (cross-contamination) can occur through inadequately cleaned kitchen equipment, such as chopping boards, knives, and towels, or through neglected washing of hands. When preparing meals, special attention should be paid to kitchen hygiene and sufficient refrigeration of raw products.

Salmonella generally grow at temperatures between 10‒47 °C and are not killed by deep-freezing. A guaranteed method for eliminating the pathogen is heat treatment at temperatures above 70 °C for at least 15 seconds.

Direct transmission of the pathogens from person to person (faecal-oral) is theoretically possible but rarely occurs with Salmonella due to the high dose of inoculum required for infection.

Reservoir

Incubation period

Farm and domestic animals (particularly poultry and

6-72 hours, usually 12-36 hours.

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Symptoms

Serotyping und phage typing

Symptoms include nausea, diarrhoea, fever, vomiting, cardiovascular problems, and abdominal cramps. Normally, symptoms only last for a few hours or days. Depending on the number of bacteria ingested, many infections take a mild or asymptomatic course. In the elderly, dehydration and resulting cardiovascular problems can lead to severe and life-threatening disease.

Typing of all Salmonella isolates takes place in the National Reference Centre for Salmonella (NRC-S) in Graz. Serotyping is done according to the WhiteKauffmann-Le Minor scheme. Bacteriophages are used to further group S. Enteritidis isolates into phage types (PT) and S. Typhimurium into definitive types (DT).

Diagnosis Detection of the pathogen is done by culturing the causative organism from stool (faeces), or from blood or pus. A test for specific antibodies in blood is not conclusive.

Treatment In the absence of risk factors, patients with gastroenteritis caused by Salmonella infection should not routinely be treated with antibiotics; antibiotic treatment can prolong the period of bacterial shedding. Usually, supportive therapy restoring the fluid and electrolyte balance is sufficient.

Preventive measures Foods, especially meat, poultry, eggs, and fresh pasta, should be well cooked and should not be stored at room temperature longer than necessary. After handling raw poultry, it is essential to wash hands before doing other kitchen work. Liquid from defrosted meat should immediately be poured into the sink and rinsed off with hot water. All cooking areas and equipment which were in contact with raw poultry or eggs must be cleaned with detergents and hot water. Fresh prepared meals which are not eaten at once should be left to cool down and immediately stored in the refrigerator.

Figure 1: Number of human salmonellosis cases in Austria, 2000-2012 and presentation of the two most important serovars, S. Enteritidis and S. Typhimurium (until 2008 primary isolates of Salmonella, since 2009 number of laboratory confirmed cases; NRC-S, as of April 30, 2013)

In 2012, 49.4 % of all typed serovars from humans were S. Enteritidis and 12.8 % were S. Typhimurium.

Table 1: Ten most frequent Salmonella serotypes in humans in Austria, 2012 (NRC-S, as of April 30, 2013)

Salmonellosis in Austria, 2012

Serotype

Humans In 2012, 1,729 laboratory confirmed cases were reported through the EMS (as of April 28, 2013). The NRC-S received 1,888 human primary isolates for typing (food-borne and non-food-borne, as of April 30, 2013); some patients were infected with two or more different Salmonella strains. The incidence rate of 20.5 cases per 100,000 population was lower than in 2011 (26.1 per 100,000 population). Compared with 2002, the incidence rate dropped by 80 % (2002: 8,405 primary isolates). The reduction in the number of human cases was due almost exclusively to the reduction of S. Enteritidis (2002: 7,459 isolates; 2012: 933 isolates), indicating that measures taken to control the transmission of Salmonella, such as mandatory vaccination of parent flocks of Gallus gallus and laying hens against S. Enteritidis, have been successful. In contrast, no clear trend could be found for other serotypes (2002: 946 isolates; 2011: 947; 2012: 955). In 2012, salmonellosis was again the second most frequent cause of bacteriological food poisoning (No. 1: campylobacteriosis cases: 4,710 laboratory confirmed cases, EMS, as of April 28, 2013).

The main PTs of S. Enteritidis were PT8, PT21 and PT13a.

Number

Percent

S. Enteritidis

933

49,4

S. Typhimurium

241

12,8

S. Stanley

146

7,7

S. Typhimurium - monophasic

96

5,1

S. Infantis

78

4,1

S. Paratyphi B var. Java

28

1,5

S. Thompson

25

1,3

S. Kentucky

21

1,1

S. Agona

18

1,0

S. Saintpaul

18

1,0

302

16,0

1.888

100,0

other serotypes Total number of human isolates

Austria and the EU compared: 2011 The Austrian incidence rate of notified human salmonellosis cases of 26.1 per 100,000 population exceeded the European average1 of 20.7/100,000. Portugal (1.6/100,000) and Greece (4.1/100,000) had the lowest incidence rates, the Czech Republic (80.7/100,000) and Slovakia (71.7/100,000) the highest.

People with salmonellosis are not allowed to work in any food-processing or food-serving establishment.

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From the European Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents and Food-borne Outbreaks in 2011, EFSA Journal 2013,11(4):3129 13


Food and food products The examination and sampling plans of the Federal Ministry of Health specify the number of food enterprises (food manufacturers, retail outlets, restaurants etc.) and food products that must be tested in each province in a given year. During these inspections, samples are taken and food processing procedures assessed.

samples of raw meat and meat products from turkey, in 2 out of 46 samples of not-ready-to-eat meat from broilers (both S. Infantis). Of 412 raw pork samples, two were contaminated with Salmonella. In one out of 141 samples of spices and herbs, Salmonella were detected. No Salmonella were found in 100 samples of raw beef, in 398 samples of mixed meat preparations, in 669 samples of milk, milk products and cheeses, 124 tested units of table eggs or 153 egg products.

In 2012, salmonella were detected in 20 out of 178 samples of raw broiler meat, including S. Infantis (n=12), S. Typhimurium (n=6) and S. Mbandaka (n=2); Salmonella were also found in 7 out of 73 3

prevalence in 2012 target

% 2 1,6 1

0

parent flocks (n = 128)

0,7

0,7

layers (n = 2,740)

broilers (n = 3,510)

0,5 turkeys (n = 375)

Figure 3: Prevalence of S. Enteritidis and S. Typhimurium in flocks of layers, broilers and turkeys, and prevalence of S. Enteritidis, S. Typhimurium, S. Infantis, S. Virchow and S. Hadar in flocks of parent animals of Gallus gallus, and achieved targets, 2012

Animals For humans, foods of animal origin are the most important source of infection with Salmonella. To determine the importance of various animal species as reservoirs for Salmonella, EU-wide baseline studies have been performed in several animal populations (see earlier editions of this report). These surveys concluded that in Austria, eggs and poultry meat were the most important sources for human salmonellosis; all other animals show very low prevalence of Salmonella.

The EU published targets for Salmonella in different poultry populations that must be confirmed by each member state. The prevalence of S. Enteritidis and S. Typhimurium in flocks of laying hens must be lower than 2 % and in flocks of broilers and turkeys below 1 %; a maximum of 1 % of parent flocks of Gallus gallus may be infected with S. Enteritidis, S. Typhimurium, S. Infantis, S. Virchow or S. Hadar. All targets were met except that concerning parent flocks. In this population, two flocks out of 128 (1.6 %) were infected with S. Enteritidis, as shown in fig. 3.

Feeding stuffs In Austria, feeding stuffs are subject to continuous monitoring, with samples drawn at farms, slaughterhouses, feeding stuff manufacturers, and retailers. Both manufactured feed mixtures and individual ingredients are officially tested. In 2012, 396 samples were examined officially, including 88 from pet food (e.g. chewing bones). Salmonella were detected in six out of 308 feed samples from food-producing animals and six samples from pet feed,

presented in fig. 4. S. Agona (n=4), S. Tennessee (n=2), and S. Derby (n=2) were the most frequently typed Salmonella serotypes among feeding stuffs. Pet food long has been seen as a risky material for Salmonella contamination, although levels of Salmonella detection in feed samples of food-producing animals have been stable over the last several years. Hands should be cleaned carefully after feeding cats and dogs with these pet products.

feed samples for food-producing animals

pet feed

600

% salmonella detected (pet feed)

500 number of samples

25%

% salmonella detected (food-producing animals)

20%

400

15%

300 10%

200

5%

100 0

percentage positive samples

Figure 2: Number of samples of poultry and poultry products tested and the prevalence of Salmonella spp., S. Enteritidis, S. Typhimurium and S. Infantis in Austria, 2001-2012

Figure 4: Officially tested feed samples in Austria, 2005-2012

0% 2005

2006

2007

2008

2009

2010

2011

2012

year

14

15


Salmonellosis cases

8 000

Campylobacteriosis cases

7 000

6 000

number of cases

5 000 4 000 3 000 2 000

1 000 0

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012

year

Figure 5: Number of campylobacteriosis and salmonellosis cases in Austria, 2000-2012 (EMS as of April 28, 2013)

CAMPYLOBACTERIOSIS Campylobacteriosis is an infectious disease caused by Campylobacter spp. ‒ bacteria in the shape of tiny

spiral rods. The most common species in humans is C. jejuni. C. coli cause 5‒10 % of human cases. These bacteria are sensitive to low pH environments and are effectively eliminated by pasteurisation.

Occurrence Campylobacteriosis occurs worldwide and mainly during warm seasons. Campylobacter is the most important pathogen causing food-borne enteric diseases in humans. In 2012, campylobacteriosis was again the most frequently notified food-borne infectious disease in Austria.

Reservoir The carriage rate of Campylobacter spp. varies in poultry, pigs, cattle, and pets. In animals, these pathogens are natural intestinal inhabitants that rarely cause enteric disease.

Mode of transmission In humans, campylobacteriosis is mainly a food-borne infection, with inadequately cooked poultry and raw milk as the main sources of infection. Special attention should be paid to hygiene during food preparation to avoid cross-contamination between raw meat and other foods. Direct transmission from person to person (faecal-oral) is rarely observed.

Incubation period Generally 2‒5 days, depending on the amount of ingested bacteria; about 500 bacteria can cause disease in humans.

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Symptoms Symptoms include high fever with abdominal pain, watery to bloody diarrhoea, headache, and fatigue for 1‒7 days. Up to 10 % of cases can acquire a postinfectious irritable bowel syndrome; in rare cases, Guillain-Barré syndrome, a disease of the nervous system, can occur as a serious complication of campylobacteriosis.

Diagnosis

Austria and the EU compared: 2011

Food and food products

The incidence rate of notified human campylobacteriosis cases of 61 per 100,000 population in Austria is clearly above the EU average2 of 50.3 per 100,000 population. The incidence rates of campylobacteriosis differ widely within the EU. Bulgaria, Italy, Poland, and

In 2012, 73 out of 147 samples of poultry meat (49.7 %) were positive for Campylobacter; 70 were raw broiler meat samples, part of a special surveillance program, of which 52 (74 %) contained Campylobacter. No Campylobacter were detected in 29 samples

Romania each reported an incidence of less than 1 per 100,000 population, Latvia reported seven cases and two member states lack a surveillance system for Campylobacter (Portugal and Greece). The highest country-specific notification rates were observed in the Czech Republic (178 per 100,000 population), Luxembourg (138 per 100,000 population), and the United Kingdom (115 per 100,000 population).

of milk or milk products, including raw milk, and in 66 samples of meat other than poultry. Beef and pork are investigated infrequently due to slighter roles as potential sources for human infections; during maturation of the meat, the surface dries up and Campylobacter cannot survive.

Campylobacter infection is diagnosed when a culture of a stool specimen yields the bacterium.

Treatment

2

From the European Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents and Food-borne Outbreaks in 2011, EFSA Journal 2013,11(4):3129

The disease is usually self-limiting and therapy which equalizes the body’s water and electrolyte balance usually is sufficient. Infants and patients with high temperature or immune-compromised individuals can be treated with antibiotics.

Campylobacteriosis in Austria, 2012 Humans In 2012, 4,710 cases of laboratory confirmed campylobacteriosis were notified (EMS, as of April 28, 2013). Campylobacteriosis remains the most frequently reported food-borne infection in Austria, with an incidence rate of 55.8 per 100,000 population. A consistent increase in the number of human cases of campylobacteriosis was observed until 2007 (6,132 cases), most likely as a result of the higher sensitivity of modern laboratory techniques and improved diagnosis rather than a true increase in the prevalence of Campylobacter spp.. Since then, the number of cases has stabilized to between 4,000 and 6,000 cases per year. The campylobacteriosis incidence will continue to receive extensive surveillance.

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number of samples

600

poultry meat samples tested

60%

% Campylobacter-positiv 50%

500

40%

400 30% 300 20%

200

10%

100 0

% samples positive

700

0%

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012

year Figure 6: Poultry meat samples tested for thermotolerant Campylobacter in Austria, 2001-2012

Animals Since 2004, Austrian poultry, cattle, and pigs have undergone annual testing in accordance with the national regulations of the monitoring programs for selected zoonotic agents in cattle, sheep, pigs, and broilers. In 2012, broiler slaughter batches were tested for the prevalence of thermotolerant Campylobacter.

Disease Control in Graz for isolation of thermotolerant Campylobacter. In 2012, Campylobacter were detected in 46.8 % out of 312 broiler flocks, depicted in fig. 7. Due to the minor importance as source for human infections, pigs and bovines are not tested every year for Campylobacter.

BRUCELLOSIS

According to the randomized sampling plan, intestines from broiler slaughter batches were taken in selected

Brucellosis is an infectious disease caused by Brucella species, a short, non-motile, non-spore-forming, rod-shaped bacteria occurring worldwide. They are sensitive to heat and all commonly used disinfectants.

abattoirs and sent to the AGES Institute for Veterinary

Occurrence

pigs

75

Campylobacter positive (%)

broilers bovines

50

25

B. melitensis mainly affects sheep and goats in Mediterranean countries. In humans, infection with B. melitensis is referred to as Malta fever. B. abortus causes abortion in cattle and Bang’s disease in humans. B. suis is uncommon in Europe and found mainly in pigs and hares.

Reservoir 0

2004

2005

2006

2007

2008

2009

2010

2011

2012

year Figure 7: Thermotolerant Campylobacter in intestines of slaughtered pigs, bovines and broiler flocks in Austria, 2004-2012

Infected farm animals (cows, goats, sheep, and pigs)

Mode of transmission Transmission to humans takes place via contaminated food (raw milk and milk products) or through direct contact with infected animals or their secretions. Person-to-person transmission occurs very rarely in isolated cases, via breast feeding or blood transfusion.

Incubation period Usually 5-60 days.

Symptoms Up to 90 % of all Brucella infections are subclinical and only detectable by demonstration of specific antibodies in the blood of infected persons that reflect a successful immune response. At the onset of acute brucellosis, symptoms are often unspecific and can include fatigue, low-grade fever, headache, and arthralgia. After a short symptom-free interval, flu-like symptoms with a night-time rise in temperature up to 40 °C is observed together with sweat, frequently associated with low blood pressure and swelling of the liver, spleen, lymph nodes, testicle and scrotum area. Without antibiotic treatment, the disease can heal spontaneously or become chronic with recurrent bouts of fever.

Diagnosis Diagnosis by culture should be based on multiple blood samples, ideally taken prior to initiation of antibiotic therapy. Bone marrow, urine, and samples from other tissues are also used to detect the bacteria, as is serological testing for specific antibodies.

Treatment Brucellosis is treated with antibiotics.

Brucellosis in Austria, 2012 Humans In Austria, brucellosis in humans occurs only sporadically. In 2012, there were three laboratory confirmed cases notified (EMS, as of April 28, 2013).

18

19


6

Brucellosis

number of cases

4

2

0

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012

year Figure 8: Brucellosis cases in Austria, 2000-2012 (EMS, as of April 28, 2013)

Austria and the EU compared: 2011

Bovine brucellosis (Brucella abortus):

In 2011, the incidence rate of brucellosis in Austria (0.06 per 100,000 population) was similar to the EU average3 (0.07 per 100,000 population). In the EU, the number of notified cases is declining; ten member states did not report any cases. Countries whose cattle population resp. small ruminants population carry the status officially brucellosis free or officially Brucella melitensis free, reported the least human cases, as expected and most as imported cases. In 2011, 64 % of reported human cases were in Greece, Portugal and Spain.

In 2008, Austria introduced new Bang’s disease regulations. In 2012, all of Austria’s 31,244 milk-producing cattle farms were required to have their bulk tanks analysed. None of the farms were positive for Brucella. Of the non-milk-supplying cattle holdings, 3,492 were selected according to a risk-based sampling plan, with blood samples for serological analysis drawn from 29,092 bovines older than 2 years. None of the tested bovines were positive for Brucella. Additionally, Brucella was not the causative agent in any of 1,118 notified cases of bovine abortions.

Food and food products

Ovine and caprine brucellosis (B. melitensis):

Because Austria has been officially declared brucellosis-free, food is not tested for Brucella spp.

To keep the OBmF status, Austria must demonstrate annually that less than 0.2 % of all sheep and goat holdings are infected. In 2012, blood samples from 17,367 sheep and goats from 1,495 holdings throughout Austria were tested based on a risk-based sampling plan. None of the animals tested positive by serology.

Animals Austria gained the statuses OBF (Officially Brucellosis Free) and OBmF (Officially Brucella melitensis Free) after cattle populations were officially declared free of Brucella abortus in 1999, and sheep and goats were declared free of Brucella melitensis in 2001, respectively.

3

20

From the European Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents and Food-borne Outbreaks in 2011, EFSA Journal 2013,11(4):3129

21


Listeriosis in Austria, 2012 Humans In 2012, isolates of 34 cases of invasive listeriosis were investigated and typed in the National Reference Centre for Listeria (NRC-L) in the AGES (NRC-L, as of April 22, 2013). Out of those, congenital listeriosis was reported in four cases (the foetus, stillborn or the new-born and the mother count as one case). In 2012, the 28-day lethality4 was 12 % (4/34). Thus, listeriosis is a rare infectious disease in Austria, with an incidence rate of 0.4 per 100,000 population.

In the EMS, 36 cases of listeriosis were notified (as of April 28, 2013); due to the fact that an isolate is not sent to the NRC-L for each notified case, the case numbers may differ. EMS data correlate with the notification data of the medicating physician and the diagnosing laboratory. The cases that were not confirmed by the NRC-L were excluded from fig. 9. According to laboratory confirmed cases in the EMS, one congenital case (the foetus, stillborn or the new-born and the mother count as two cases) was reported; lethality caused by listeriosis was 3 % (1/36).

LISTERIOSIS infection is mostly asymptomatic; however, infection of the unborn child may result in preterm or still birth. Infected infants often develop meningitis.

Occurrence

Diagnosis

The pathogen is widely distributed in the environment, from sewage water to soil and plants. Food products of animal origin, such as raw milk, soft cheese, smoked fish, and raw meat, can become contaminated during the production process (e.g., during milking or at slaughter). The bacterium can be found in foodprocessing plants, where it is feared for becoming a difficult to eliminate ‘domestic pathogen’. Unlike most other zoonotic bacteria, L. monocytogenes can multiply in low-temperature environments, such as refrigerators.

Listeriosis is confirmed by culturing the infectious agent from blood, cerebrospinal fluid, pus, or stool.

Reservoir Ruminant animals (especially cattle, sheep, and goats) and contaminated production facilities.

45 40

Treatment Listeriosis is treated with antibiotics. Despite specific therapy, up to 25 % of invasive listeriosis cases result in death.

letal cases

35 30 25 20

15 10 5 0

Preventive measures Compliance with common kitchen hygiene rules is important to avoid infections with L. monocytogenes. Rules to minimise the risk of food-borne infection include:

Listeriosis cases

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 year

Figure 9: NRC-L confirmed cases of invasive listeriosis and lethal cases (28-day lethality4) in Austria, 2000-2012 (NRC-L, as of April 22, 2013)

Thoroughly cooking meat and fish dishes

Mode of transmission

Boiling raw milk before consumption

Austria and the EU compared: 2011

Consumption of contaminated foods of animal or vegetable origin is the main transmission route, although transmission among humans (e.g., nosocomial infection of neonates) and infection through direct contact with carrier animals can occur.

No consumption of raw minced meat

Keeping food items that pose a higher risk for Listeria contamination, such as soft cheeses, smear cheeses or smoked fish, separated from other dishes and no longer than shelf life

With 0.31 per 100,000 population, the incidence rate of confirmed human listeriosis cases in Austria is similar to the EU average5 of 0.32 per 100,000 population.

Incubation period In case of food-borne infection, symptoms of invasive listeriosis occur within 3‒70 days.

Symptoms In healthy adults, infection with L. monocytogenes does not, in most cases, cause disease, even though some may develop diarrhoea. In immune-compromised individuals, such as neonates, the elderly, and patients with chronic diseases, invasive listeriosis with sudden intense headache, high fever, nausea, and vomiting can occur. In severe cases, patients can develop meningitis or sepsis; about one-fourth of those cases have a fatal outcome. In pregnant women, the 22

50

number of cases

Listeriosis is an infectious disease caused by Listeria monocytogenes, a short, non-spore forming, and rodshaped bacterium.

The incidences vary in the EU from 0.04 per 100,000 population in Romania to 0.88 per 100,000 population in Denmark.

Regular washing of hands before and after the preparation of meals is an important measure of protection against pathogens. Vegetables and salads should be washed properly before eating. Meat and raw vegetables should be prepared on separate kitchen worktops or at separate times. Worktops should always be cleaned thoroughly after use. Freshly cooked meals should be covered when stored in the refrigerator to avoid later contamination.

4 5

28-day lethality = total lethality within 28 days post diagnosis From the European Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents and Food-borne Outbreaks in 2011, EFSA Journal 2013,11(4):3129 23


TRICHINELLOSIS 400

6%

% L. monocytogenes -positive

350

5%

300 250

4%

200

3%

150

2%

100

fermentied sausages

meat and meat products, all animal species, raw, ready to eat

meat and meat products, all animal species, raw, not ready to eat

smoked fish

fishery products

milk products (without cheeses)

cheeses made from mixed milk

cheeses made from sheep's milk

cheeses made from goat's milk

0%

cheeses made from pasteurized cow's milk

0

cheeses made from raw cow's milk

1% milk, cow's pasteurized

50 milk, cow's raw

number of samples

7%

samples tested

positive samples

450

Figure 10: Foodstuffs of animal origin tested for Listeria monocytogenes in Austria, 2012

Food and food products The examination and sampling plans of the Federal Ministry of Health specify the number of food enterprises (food manufacturers, retail outlets, restaurants etc.) and food products that must be tested in each province in a given year. During these inspections, samples are taken and food processing procedures are assessed. In 2012, L. monocytogenes was found in two out of 1,181 samples of milk, milk products or cheeses (see fig. 10) and in nine out of 168 samples of fish products and in two out of 72 smoked fish samples. Among 570 samples of meat and meat products from different animal species, including raw or cooked, ready-to-eat or not-ready-to-eat items, L. monocytogenes could be found in 31 samples; out of those, the pathogen was most frequently found in cooked, ready-to-eat pork

(12 out of 148 samples). Six out of 176 samples of fermented sausages were contaminated with L. monocytogenes. Among other sampled foodstuffs, including salads, sauces, dressings, and vegetables, L. moncytogenes was detected in three out of 313 samples. Out of all L. monocytogenes positive food samples, in only four samples (two samples of smoked fish and two samples of cooked, ready-to-eat pork), the pathogen was present in 10-100 colony-forming units (cfu); none of the samples exceeded 100 cfu of L. monocytogenes. Animals In most cases, food is contaminated with Listeria monocytogenes during production in processing plants. Therefore surveillance of animal populations for this pathogen is not appropriate.

Trichinellosis, also called trichinosis, is an infectious disease caused by the parasitic nematodes of the genus Trichinella, also referred to as trichina worm. In addition to the classical agent Trichinella spiralis, other species of Trichinella are now recognized.

Occurrence Trichinellosis occurs worldwide as a mammalian zoonosis that is independent of climate conditions. Currently in Europe the disease is infrequent but has been described as re-emerging in certain regions.

Reservoir Pig meat, wild boars meat, other game meat, and horse. Rats and rodents are primarily responsible for maintaining the endemicity of this infection.

Mode of transmission The infestation starts through ingestion of raw or improperly processed meat containing encysted Trichinella larvae. The larvae are released by digestive enzymes into the gut and, within a few days, develop into small worms in the mucosal cells of the upper small intestine. As early as 4‒7 days after ingestion, the female worms release larvae that migrate to the striated muscles where they encyst. Encystment is completed in 4 to 5 weeks and the encysted larvae may remain viable for several years. The preferred tissues are oxygen-rich muscles, such as those of the diaphragm, neck, jaw, shoulder girdle, and upper arm.

Incubation period The first symptoms of trichinellosis are gastrointestinal and usually occur 1-2 days after a person consumes raw or undercooked meat from a Trichinella-infected animal. The incubation period is generally between 5 and 15 days, depending on the number of ingested Trichinella larvae. Although data on the number of ingested larvae required to cause clinical infestation in humans vary, more than 70 larvae appear to be sufficient to cause an infestation. Transmission from human to human is not possible.

Symptoms Gastrointestinal symptoms depend on the number of ingested larvae and include nausea, diarrhoea, vomiting, and abdominal pain. The classic trichinellosis symptoms often occur within 2 weeks after eating contaminated meat, and can last up to 8 weeks, with muscle pain, fever, headache, chills and swelling of the face, particularly the eyes.

24

Diagnosis The presumptive diagnosis can be confirmed by detection of Trichinella antibodies in the blood or by muscle biopsy.

Treatment With bed rest and the aid of symptomatic treatment such as analgesic or antifebrile remedies, individuals with mild infection normally recover without complications. Severe infections are treated with anthelmintic (anti-worm) medication.

Preventive measures The best way to prevent trichinellosis is to cook meat to safe temperatures. Another preventive measure involves the mandatory carcass inspection of possible host animals to detect encapsulated larvae. Heating meat to over 70 °C or deep-freezing it below –15 °C for 20 days will kill the parasite. Smoking, pickling, and drying are insufficient for irreversibly inactivating the larvae.

Trichinellosis in Austria, 2012 Humans All cases of trichinellosis notified to the Austrian health authorities over the past three decades have been imported. In 2012, no single case of laboratory-confirmed trichinellosis in humans was reported (EMS, as of April 28, 2013).

25


7 cases of trichinellosis

number of cases

6

5

5 4 3

3 2

2 1

1 0

0

1 0

0

0

0

0

0

0

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 year

Figure 11: Cases of trichinellosis in Austria, 2000-2012 (since 2010: EMS, as of April 28, 2013; previous years: National Neference Centre for Toxoplasmosis, Echinococcosis, Toxocariasis and other Parasites)

Austria and the EU compared: 2011

Food and food products

In Austria, one case of trichinellosis was notified in 2011; the incidence rate of 0.01 per 100,000 population was below the EU average6 of 0.05 per 100,000 population. In 2011, human trichinellosis cases in the EU increased by 20.2 % to 363 cases, but still fell short of numbers reported between 2007 and 2009. Latvia, Lithuania, Romania, Bulgaria and Slovakia reported the highest incidence rates in the EU in 2011 (2.24, 0.89, 0.50, 0.36 and 0.24 cases per 100,000 population, respectively and these countries accounted for 84.3 % of all confirmed cases reported.

In 2012, carcasses of 5,396,345 pigs, 933 horses, and 34,157 wild boars (of which 33,426 were wild and the rest farmed) underwent official meat inspection; no specimens tested positive for Trichinella larvae.

Echinococcosis is a parasitic disease caused by infection with tiny tapeworms of the genus Echinocococcus. Echinococcosis is classified as either cystic echinococcosis or hydatidosis (E. granulosus) or alveolar echinococcosis (E. multilocularis).

Occurrence

number of carcasses tested

10 000 000 1 000 000

pigs

wild boars, wild

100 000

wild boars, farmed horses

10 000

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 year

Figure 12: Carcasses tested for Trichinella larve in Austria, 2001-2012

Animals Industrially raised pigs are normally free of Trichinella because they do not have the opportunity to feed on Trichinella-infested fresh meat. However, wild boars are potential Trichinella carriers.

6

26

Whereas E. multilocularis, a tapeworm found in foxes, occurs mostly in the northern hemisphere (Central and Eastern Europe, areas in the former Soviet Union, Turkey, Japan, USA, and Canada), E. granulosus, a tapeworm found in dogs, occurs worldwide, with clusters in the Mediterranean region and in the Balkan states.

Reservoir

1 000 100

ECHINOCOCCOSIS

E. granulosus: intermediate hosts: sheep, pigs, cattle definitive hosts: dogs E. multilocularis: intermediate hosts: small rodents definitive hosts: foxes

Mode of transmission The adult Echinococcus granulosus (“dog tapeworm”, 3 to 6 mm long) resides in the small bowel of the definitive hosts, dogs or other canids. Gravid proglottids (segments of the worm) release eggs via faeces into the environment. After ingestion by a suitable intermediate host (under natural conditions: sheep, goat, swine, cattle, horses), the egg hatches in the small bowel and releases an oncosphere (larva) that penetrates the intestinal wall and migrates through the circulatory system into various organs, especially

the liver and lungs. In these organs, the oncosphere develops into a hydatid cyst that enlarges gradually, producing protoscolices (small heads) and daughter cysts that fill the cysts´ interior. The definitive host becomes infested by ingesting the cyst-containing organs of the infested intermediate host, developing new adult tapeworms.

E. multilocularis (“fox tapeworm”): The 2‒3 mm long five-segmented worms are found in the small intestines of foxes. Cats and dogs are only rarely infested. Every 1‒2 weeks, the final segment of each tapeworm, which contains up to 500 eggs, detaches and is released into the environment via the host’s f­aeces. If adequate intermediate hosts (rodents) ingest tapeworm eggs in the contaminated ground, the eggs hatch and release larvae invading the host’s intestinal mucosa and reaching the inner organs, especially the liver; larval growth remains indefinitely in the proliferative stage, resulting in invasion of the surrounding tissues similar to a malignant tumour. Humans may become infected via accidental ingestion of tapeworm eggs present on food contaminated with faeces of affected definitive hosts.

Incubation period Cystic echinococcosis: months to years Alveolar echinococcosis: 5‒15 years

Symptoms Persons with cystic echinococcosis often remain asymptomatic until hydatid cysts containing the larval

From the European Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents and Food-borne Outbreaks in 2011, EFSA Journal 2013,11(4):3129 27


Echinococcosis in Austria: 2012

Food and food products

Humans

During mandatory meat inspection, every carcass of a potential intermediate host is examined for tapeworm cysts. In 2012, 679,772 cattle, 130,756 sheep, 5,147 goats, and 5,396,345 pigs were examined. Unspecified tapeworm cysts were detected in 135 cattle and 278 sheep. Six out of the 135 carcasses of cattle were declared unfit for human consumption; the other carcasses with very low number of detected cysts were made fit for consumption by deep-freezing overseen by the official veterinarian.

In 2012, three laboratory confirmed cases of echinococcosis were notified in Austria (EMS, as of April 28, 2013). In two cases, cystic echinococcosis was diagnosed and one case, alveolar echinococcosis. One of the cases of cystic echinococcosis was confirmed as acquired abroad. parasites grow large enough to cause discomfort, pain, nausea, and vomiting. The cysts grow over the course of several years before reaching maturity and the rate at which symptoms appear typically depends on the location of the cyst. Alveolar echinococcosis is characterized by parasitic tumours in the liver and may spread to other organs including the lungs and brain. The larval forms invade and destroy surrounding tissues and cause discomfort or pain, weight loss, and malaise. Alveolar echinococcosis can cause liver failure and death due to spread into nearby tissues and, rarely, the brain.

Diagnosis Cystic echinococcosis: Imaging techniques, such as computed tomography (CT) scans, ultrasonographies, and MRIs, are used to detect cysts. After a cyst has been detected, serologic tests may be used to confirm the diagnosis. Alveolar echinococcosis: Imaging techniques, such as CT scans, are used to visually confirm the parasitic vesicles and cyst-like structures. Serologic tests can confirm the parasitic infection.

Treatment Cystic echinococcosis: In the past, surgery was the only treatment for echinococcal cysts. Chemotherapy, cyst puncture, and PAIR (percutaneous aspiration,

35

Alveolar echinococcosis: The treatment of alveolar echinococcosis is more difficult than cystic echinococcosis and usually requires radical surgery, long-term chemotherapy, or both.

Austria and the EU compared: 2011 In 2011, seven cases of echinococcosis were notified; the incidence rate in Austria (0.08 per 100,000 population) was below the EU average7 of 0.18 per 100,000 population. The highest notification rate was reported by Bulgaria (4.09 per 100,000 population), accounting for 39 % of all cases in the EU (307 out of 781 cases).

Animals In Austria, dogs are generally free of the tapeworm E. granulosus. Foxes infected with E. multilocularis are chiefly found in Vorarlberg and Tyrol, but have also been found in other provinces.

Preventive measures Echinococcus eggs tolerate low temperatures and can therefore stay infectious for months. However, dehydration and high temperatures kill eggs within a short time. To avoid infestation with E. granulosus, dogs should be de-wormed regularly. Prevention measures include limiting the areas where dogs are allowed and preventing animals from consuming meat infected with cysts. Hand washing with soap and warm water should be performed after handling dogs and before handling food. Alveolar echinococcosis can be prevented by avoiding contact with wild animals such as foxes. After contact with foxes or fox furs, hands should be washed with soap and warm water.

cystic echinococcosis

30 number of cases

injection of chemicals and reaspiration) have been used to replace surgery as effective treatments for cystic echinococcosis. However, surgery in combination with anthelmintic therapy remains the most effective treatment to remove the cyst and can lead to a complete cure.

alveolar echinococcosis

25 20 15 10 5 0

2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 year

28

Figure 13: Number of echinococcoses (cystic und alveolar) in Austria, 2002-2012 (from 2010 on: EMS, as of April 28, 2013; previous years: National Reference Centre for Toxoplasmosis, Echinococcosis, Toxocariasis and other Parasites)

7

From the European Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents and Food-borne Outbreaks in 2011, EFSA Journal 2013,11(4):3129 29


logical reaction of the patient to injected components of cultured mycobacteria. A positive test result can be obtained 6 weeks after an infection with mycobacteria. This skin test is increasingly being replaced by interferon-gamma release assays, blood tests for TB infections. Imaging procedures: Chest radiographs reveal characteristic changes in lung tissues. However, X-ray examination alone is not sufficient to distinguish between tuberculosis and other pulmonary diseases.

TUBERCULOSIS DUE TO MYCOBACTERIUM BOVIS Tuberculosis (TB, ‘consumption‛) is a leading cause of

nary tuberculosis) in 80 % of patients, although it can

death by a single infectious agent worldwide. Tuberculosis is caused by bacteria belonging to Mycobacterium tuberculosis complex. The most common pathogen of tuberculosis in humans is Mycobacterium tuberculosis, a non-motile, rod-shaped bacterium. M. bovis is responsible for bovine tuberculosis and for only about 1 % of all human tuberculosis cases in Austria. M. caprae is a species related to M. bovis.

also affect other organs. In cases of open pulmonary tuberculosis, the bacteria can be found in the sputum of affected persons. After zoonotic transmission via food, the intestinal tract and their local lymph nodes may be affected.

Occurrence Tuberculosis is prevalent worldwide, especially in Africa, Asia, and Latin America. The risk of infection is particularly high for persons in close direct contact with patients with open, i.e., infectious, tuberculosis. An alarming increase in tuberculosis caused by multidrug resistant strains, particularly those resistant to the anti-mycobacterial drugs isoniazid and rifampicin, has been observed in recent years. The bacteria can be inactivated through pasteurization (temporary heating to over 70 °C), but not by dehydration or refrigeration.

Reservoir Humans are the only relevant reservoir for M. tuberculosis. Reservoirs for the zoonotic bacteria M. bovis and M. caprae include humans and cattle and occasionally goats and wild ruminants (e.g., red deer).

Mode of transmission Whether tuberculosis develops depends on the frequency and intensity of exposure, the amount of inhaled (human to human) or orally ingested (zoonotic, via food) pathogens, and the health status of the affected person. After inhalation of small air-borne droplets released through the coughing or sneezing of infective carriers, TB manifests in the lungs (pulmo30

Transmission through ingestion of raw (unpasteurised) milk from infectious cattle is theoretically possible, but of little relevance in Austria because Austria’s cattle livestock has been officially declared free of bovine tuberculosis.

Incubation period

Bacteriological diagnosis: A positive culture test result confirms the diagnosis of tuberculosis. The advantage of bacteriological diagnosis is the possibility to test the pathogen for resistance to different anti-mycobacterial drugs (resistance testing).

Treatment

for those who have potentially been exposed to the patient (e.g., index case, family, friends, co-workers, health care personnel etc.) to minimize the risk of secondary infections. Details can be found at: http:// bmg.gv.at/home/Schwerpunkte/Krankheiten/Uebertragbare_Krankheiten/Oesterreichische_Leitlinie_zur_ Tuberkulose_Umgebungsuntersuchung

Tuberculosis in Austria: 2012 Humans In 2012, 404 human cases of tuberculosis confirmed by culture were notified (NRC-Tuberculosis, as of June 7, 2013). One of the patients had been infected with M. bovis, another one with M. caprae, maintaining the low level of zoonotic mycobacterioses as seen in previous years. The M. caprae case was not associated with the occurrence of M. caprae in livestock in western parts of Austria (see animals chapter).

Long treatment duration is required because mycobacteria proliferate quite slowly and can rest in tuberculosis granuloma for a long time; this increases the risk of developing antimycobacterial resistance. In the case of confirmed tuberculosis, the patient has to be treated with a combination therapy including several specific anti-mycobacterial drugs.

Preventive measures With no effective vaccine against tuberculosis, the most important measure is to identify infected persons and to treat them effectively. After making a diagnosis of tuberculosis, it is essential to actively search

The incubation period can last from months in children to many years.

Symptoms Within 3‒6 weeks following airborne infection, small foci of inflammation form in the lungs in response to the presence of bacteria; these lesions develop into small encapsulated lumps (tubercles). This form is referred to as non-infectious tuberculosis; it is not contagious because no pathogens are emitted. An active case of TB starts with the common symptoms of an influenza-like infection, including fever, fatigue, loss of appetite, weight loss, and general malaise. If the respiratory tract is affected, cough, breathlessness, and blood-stained sputum can occur; patients are highly contagious. Miliary tuberculosis occurs when the bacteria spread into the lungs and other organs via the bloodstream. In such cases, tuberculous meningitis can develop.

Diagnosis Tuberculin skin test: To identify an infection without symptoms, the tuberculin skin test (Mendel-Mantoux method) can be used. This test assesses the immuno-

Figure 14: Culture confirmed cases of tuberculosis (Mycobacterium tuberculosis complex) and cases caused by M. bovis or M. caprae in Austria, 2001-2012 (NRC-Tuberculosis, as of June 7, 2013)

31


Austria and the EU compared: 2011 In 2012, two human cases of zoonotic tuberculosis caused by M. caprae were notified in Austria and none due to M. bovis. Throughout the EU8, only M. bovis cases were reported; the most cases were notified in Germany (n = 38), the United Kingdom (n = 31) and Spain (n = 22). The Officially Tuberculosis Free status (OTF) for bovine herds is currently held by Austria, Belgium, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Latvia, Luxembourg, the Netherlands, Poland, Slovakia, Slovenia, Sweden, certain provinces in Italy, Scotland, Norway, and Switzerland. Food and food products In 2012, no cases of M. bovis were detected in cattle, sheep, goats, or pigs. Animals In 1999, Austria’s cattle holdings achieved Officially Tuberculosis Free Status (OTF). The key components of the national tuberculosis surveillance program are mandatory inspections of animals at slaughter and meat inspections. In the spring of 2008, a slaughtered cow in the Tyrol was diagnosed with M. caprae during routine meat inspection. Subsequently, additional animals were

found to be infected. Molecular biological typing of the isolates showed that the causative strain was identical to the strain that caused isolated cases of tuberculosis among cattle and free-living red deer in Lechtal, Tyrol and the neighbouring Allgaeu (Germany). Epidemiological investigation of all newly occurring cases showed that the animals had either stayed in this alpine region or they had come into direct contact with animals from infected holdings. In the fall of 2008, the Federal Ministry of Health therefore required tuberculin skin tests to be performed in cattle subject to mandatory inspection in the affected Tyrolean districts. In 2012, 6,501 bovines were tested in the simultaneous tuberculin skin tests and infections with M. caprae were confirmed microbiologically in animals of three holdings; M. bovis was not detected. Additionally increased hunting of red deer, the implicated reservoir for M. caprae, was initiated to reduce the population size and detailed post-mortem examinations were performed. In the designated area, all hunted red deer and fallen game underwent required examinations by the official veterinarian. After indication of suspicious cases of tuberculosis, the affected organs were sent to the National Reference Laboratory for Bovine Tuberculosis (AGES Moedling). In 2012, M. caprae was microbiologically detected in 67 hunted games from the designated area.

VEROCYTOTOXIGENIC ESCHERICHIA COLI (VTEC) Verocytotoxigenic Escherichia coli (VTEC) are mostly motile, rod-shaped bacteria characterised by their ability to produce special toxins designated verocytotoxins. Based on their variable antigen structures, E. coli are classified into different serovars; E. coli O157:H7 is the most important and common VTEC. E. coli bacteria are sensitive to heat but survive in frozen food and acid environments. The term Shiga toxin-producing E. coli (STEC) is used synonymously with VTEC. If humans affected by VTEC present clinical symptoms such as bloody diarrhoea or Haemolytic-Uraemic Syndrome (HUS), the VTEC is classified as enterohaemorrhagic E. coli (EHEC).

Occurrence E. coli are part of the normal intestinal flora of warmblooded animals, including humans. However, verocytotoxigenic E. coli are pathogens that can produce severe diarrhoea in humans. VTEC was identified in 1982.

Incubation period Symptoms occur within 2 and 8 days, usually 3-4 days.

Symptoms The disease starts with watery diarrhoea that may become bloody after a few days and may be accompanied by severe nausea, vomiting, and abdominal pain. In most cases, the illness is self-limiting and ends within 8‒10 days. A few days after the onset of diarrhoea, about 10 % of patients, especially infants, the elderly, and people with compromised i­mmune systems, can develop a secondary disease, i.e., the potentially life-threatening Haemolytic-Uraemic Syndrome (HUS). The toxins bind to and damage receptors on the cell walls, leading to micro-vascular lesions and, subsequently, to renal failure, reduced ­urine output, anaemia, low platelet counts, intradermal haemorrhage, and neurological changes.

Reservoir All kinds of ruminants (cattle, sheep, and goats) and wildlife animals (roe and deer).

Mode of transmission Transmission of the bacteria can occur through the ingestion of the following foods: raw minced beef, pâté,

8

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From the European Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents and Food-borne Outbreaks in 2011, EFSA Journal 2013,11(4):3129

salami, raw milk, and foods of plant origin grown on soil fertilized with bovine manure (e.g., sprouts). Other routes of transmission include contact with ruminants (petting zoos) if hands are not cleaned properly (i.e., washed with soap) or through person-to-person contact, especially in social areas, such as kindergartens or senior residences. The infectious dose is very low (approx. 50-100 organisms). 33


Diagnosis

Preventive measures

If infection is suspected on clinical grounds, the diagnosis is based on culturing of the VTEC from stool samples, detection of verocytotoxin in stool or by determination of specific antibodies in blood.

Food-related precautions: Because ruminants are possible reservoirs for VTEC bacteria, practicing good hygiene, such as hand washing after contact with animals and before food intake, at all stages of production, processing, storage, transport, and retail of food products is of great importance.

Treatment Antimicrobial treatment is generally c­ ontraindicated; the bacteria may produce more toxins under the influence of antibiotics and increase the rate of complications. Antidiarrhoeal agents may also increase that risk. Non-specific supportive therapy, including hydration, is important. If severe secondary disease (e.g., HUS) develops, treatment in an intensive care unit and haemodialysis may be necessary.

Precautions in the food processing industry: Persons infected with VTEC are not allowed to work in commercial food production, handling, or marketing until the local health authority has confirmed that they are no longer shedding the pathogen. This also applies to kitchen employees, e.g., in restaurants, cafeterias, hospitals, children’s homes, and catering services.

O104:H4 that included 3,800 cases in Germany and associated cases in 15 other EU-member states. Germany had the highest incidence rate of 6.8 cases per 100,000 population (5,558 confirmed cases). Food and food products The examination and sampling plans of the Federal Ministry of Health specify the number of food enterprises (food manufacturers, retail outlets, restaurants etc.) and food products that must be tested in each province in a given year. During these inspections,

samples are taken and food processing procedures assessed. In 2012, VTEC were detected in four out of 185 raw meat samples from farmed ruminants and in ten out of 38 raw meat samples from game. Three out of 149 fermented sausages and two out of 66 sausages from game were contaminated with VTEC. In two out of 63 samples of ready-to-eat food and in four out of 48 samples of cheeses, VTEC were found. VTEC were not detected in ten samples of raw milk.

VTEC infection in Austria, 2012 Humans In 2012, 146 infections with VTEC were diagnosed in the NRC-VTEC (as of April 24, 2013). The incidence rate was 0.21 per 100,000 population. 127 cases were reported to the EMS (as of April 28, 2013). The different number of cases could be due to cases infected with multiple different strains or delayed sending of the patient isolates to the NRC-VTEC. The increase in cases that has been observed since 2011 may be due to intensified national screening after the large VTEC-outbreak in Germany in 2011 caused by VTEC O104:H4. According to NRC-VTEC data, 18 out of the 146 VTECinfections developed HUS. In the EMS, 17 laboratory confirmed cases were notified; in one case HUS status was not notified. Austria and the EU compared: 2011 In 2011, the incidence rate of confirmed VTEC infections was 1.43 per 100,000 population. That rate was below the EU average9 of 1.93 per 100,000 population. In 2011, an increase of 160 % observed in the EU, largely due to an outbreak of enteroaggregative VTEC

Figure 15: VTEC-infections and cases of Haemolytic-Uraemic Syndrome in Austria, 2001-2012 (NRC VTEC, as of April 24, 2013)

One of the 25 VTEC isolates harboured the eae-gene coding for intimin, an essential virulence factor for VTEC to cause disease in humans. This eae-positive VTEC O51:H49 was isolated from a beef sample. Animals Since 2004, Austrian cattle and sheep holdings have undergone annual testing in accordance with the regulations of the national monitoring programs for selected zoonotic agents in cattle, sheep, pigs, and 9

34

broilers. In 2012, specific randomised sampling plans were developed for cattle and sheep to monitor for the presence of VTEC. A rectum sample of slaughtered cattle was sent to the laboratory where swab samples of the recto-anal mucosa were taken and examined. The sampling of sheep was performed at the holding by taking a swab sample of recto-anal mucosa. To comply with specifications, the cooled samples (rectum or swab) had to

From the European Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents and Food-borne Outbreaks in 2011, EFSA Journal 2013,11(4):3129

35


be sent to the AGES Institute for Veterinary Disease Control in Graz within two days. In 2012, 116 samples from cattle and 124 from sheep were examined.

Sheep: Verocytotoxin was detected in 70 % of swabs (2011: 82 %) and VTEC isolated from 80 samples (65 %; 2011: 68 %). One isolate harboured the eaegene, a VTEC O157:H7 strain.

Cattle: Verocytotoxin was detected by ELISA in 46 % of samples, compared to 77 % in 2011; VTEC were isolated in 41 samples (35 %; 2011: 39 %). Two isolates were identified as VTEC O157, the most important serotype causing diseases in humans, compared to 6 VTEC O157 in 2011. Six VTEC-isolates harboured the eae-gene.

Figure 17: Samples from cattle and sheep positive for verocytotoxin, VTEC isolated, VTEC harbouring eae-gene or VTEC O157-serotype in Austria, 2012 (VT-ELISA positive: verocytotoxin detected by ELISA; VTEC isolated: verocytotoxigenic E. coli isolated from sample)

Figure 16: Food items examined for VTEC and results in Austria, 2012

36

37


Symptoms Healthy people who become infected with T. gondii often do not have symptoms because their immune systems typically keep the parasite from causing illness. Cysts can develop in tissue, including brain, retina, heart-muscles or striated muscles, as a reaction to the immune system. However, the parasite remains inactive in the body.

TOXOPLASMOSIS Toxoplasma (T.) gondii, a single-celled, intracellular, obligate parasite, causes a disease known as toxoplasmosis. People typically become infected by three principal routes of transmission: food-borne, animalto-human, and mother-to-child (congenital).

Occurrence Infections with T. gondii are found throughout the world. All warm-blooded animals, including humans, are possible intermediate hosts. The only known definitive hosts for T. gondii are members of the Felidae family (domestic cats and their relatives).

Reservoir Intermediate host: The spectrum of possible hosts that can be infected by unsporulated oocysts (from definitive hosts) or by consumption of meat harbouring tissue cysts includes humans, sheep, goats, rodents, pigs, chicken and birds. Definitive host: Cats become infected after consuming intermediate hosts harbouring tissue cysts; they may

also become infected directly by ingestion of sporulated oocysts. The parasites reproduce sexually in the intestinal tract of cats and unsporulated oocysts are shed in the cat’s faeces.

Mode of transmission Intermediate hosts, including humans, acquire the infection orally through ingestion of oocysts after contact with shedding cats, a cat‘s litter box or via vegetables contaminated with cat‘s faeces or by eating undercooked meat (e.g. lamb or pork) harbouring tissue cysts. If an individual becomes infected for the first time with Toxoplasma during or just prior to pregnancy, then the infection can pass on to the unborn baby.

Incubation period Symptoms typically occur 10-23 days after consumption of meat harbouring tissue cysts and 5-20 days after uptake of oocysts.

If a woman experiences her first infection with T. gondii during pregnancy, the possibility of a congenital Toxoplasma infection depends on the pregnancy stage when the infection occurs. The later during pregnancy the infection occurs, the higher the probability that the pathogen reaches the foetus, causing a transplacental infection. The severity of disease occurs inversely; if the infection is acquired during the first third of pregnancy, the embryo often dies. Clinical manifestations of the foetus have often been observed after infection during the second trimester of pregnancy and include development of hydrocephalus, calcification of the brain and severe eye damages. Infection during the last third of pregnancy most frequently results in clinically unremarkable new-borns. However long-term sequelae can develop after months or years, presenting as a developmental disorder, psychic retardation or ocular diseases with progressive loss of vision that can lead to blindness. Persons with compromised immune systems may experience severe symptoms if they are infected with Toxoplasma while immunosuppressed. The parasite can multiply uninhibited and cause toxoplasmic encephalitis (inflation of the brain).

Diagnosis The diagnosis of toxoplasmosis is typically made by serologic testing. Diagnosis can be made by direct observation of the parasite in stained tissue sections, cerebrospinal fluid (CSF), or other biopsy material by

microscopy or polymerase chain reaction. Molecular techniques that can detect the parasite‘s DNA in the amniotic fluid can be useful in cases of possible mother-to-child (congenital) transmission.

Treatment If symptoms occur, antibiotic-antiprotozoal combinations are used to treat patients.

Preventive measures Seronegative pregnant women should avoid contact with new or unfamiliar cats and abstain, as pregnant women should in general, from undercooked meat. Vegetables and fruits should be peeled or washed thoroughly. Freezing of meat at -20 °C for 24 hours inactivates possible present cysts. Lamb is regarded as the main source of food-borne toxoplasmosis. Work gloves should be used for garden work. Cats should not have access to kitchens and areas where food is prepared.

Toxoplasma infection in Austria, 2012 Humans In Austria, notification of toxoplasmosis is not mandatory. The toxoplasmosis laboratory of the Department of Paediatrics and Adolescent Medicine10 tests amniotic fluid sent by prenatal centres and umbilical cord blood of infected pregnant women from hospitals all over Austria. The infectious status of the child of an infected mother is surveyed in follow-up studies. In 2012, 106 cases of maternal infection, an incidence of 1.36 maternal infections per 1,000 pregnancies, and 8 congenitally-acquired infections, an incidence of 1.0 infantile infection per 10,000 live births, were diagnosed. Both incidences are minimal.

10

38

Laboratory for Toxoplasmosis Department of Paediatrics and Adolescent Medicine Medical University of Vienna 1090 Vienna, Waehringer Guertel 18-20 Department Head: Univ. Prof. Dr. Michael Hayde

39


Austria and the EU compared: 2011 No toxoplasmosis data were published in the EUSR 201111. Food and food products

samples, 193 sheep samples, 184 goat samples, and 13 samples from cats were examined. Toxoplasma antibodies or T. gondii (direct or indirect observations) were detected in 1 bovine, 2 pigs, 82 sheep, 56 goats, and 1 cat.

Figure 18: Diagnosed infections of maternal and congenitally acquired toxoplasmosis in Austria, 2009-2012 (Laboratory for Toxoplasmosis of the Department of Paediatrics and Adolescent Medicine, Medical University of Vienna, as of June 19, 2013)

Food has not been tested for Toxoplasma cysts in Austria in the last several years. Animals In the event of an abortion or other occurrence of clinical interest, livestock and cats are tested for T. gondii. From 2008-2012, 71 bovine samples, 30 pig

11

From the European Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents and Food-borne Outbreaks in 2011, EFSA Journal 2013,11(4):3129

Figure 19: Tested bovines, pigs, sheep, goats and cats for Toxoplasma antibodies or T. gondii oocysts in Austria, 2008-2012

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FOOD-BORNE OUTBREAKS IN AUSTRIA Consumers expect hygienic food-products and food industries place high value on the quality of their products. In the event of human illness after consumption of food contaminated with pathogens, investigations should attempt to determine the cause. If only a single case occurs, it is nearly impossible to find the source of infection due to the variety of foods consumed and exposures. However, in the occurrence of a food-borne outbreak with more people affected, the likelihood of identifying the vehicle for the causative agent, by analysing associations of the exposure with illness, is much higher.

Definition According to the Directive 2003/99/EC, a food-borne outbreak is defined as an incidence, observed under given circumstances, of two or more human cases of the same disease and/or infection or a situation in which the observed number of cases exceeds the expected number and where the cases are linked, or are probably linked, to the same food source.

Why should outbreaks be investigated? Is there a necessity to investigate outbreaks? Or is this only a gimmick for academics? Is this effort only conducted to fulfill legislation? The food vehicle and the reservoir of the causative agent (e.g., processing plant or primary production) should be identified to set targeted and useful interventions. Those measurements should result in removing the causative agent from the food chain so that consumers are no longer exposed to it. The aim of an outbreak investigation is

40

to halt an on-going event and also to prevent incidents from occurring in the future. A historical example demonstrates the great preventive potential of a successful outbreak investigation. In July 2004, a Salmonella Enteritidis phage type 36 outbreak, which affected 38 people across four of the nine Austrian provinces, could be traced back to the eggs from a layers flock. The flock was culled and the stables carefully cleaned and disinfected. Subsequently the holding was restocked with layers but, since then, no new cases of Salmonella Enteritidis phage type 36 have been diagnosed in Austria (fig. 20).

Who conducts investigations of outbreaks? According to the national Epidemics Act, in the event of a notifiable disease or a food-borne outbreak (or suspected outbreak), the local authorities, via their official physicians, immediately must initiate investigations to determine the extent of the disease and the source of infection. Furthermore the national Zoonosis Act of 2005 requires the competent authorities to investigate food-borne outbreaks and to conduct adequate epidemiological and microbiological assessments. The authorities may bring in experts. In the past, intensified sampling of foodstuffs alone has been inadequate. In many cases, at the start of the outbreak investigation, the food vehicle or the contaminated batch of food was no longer available for microbiological examinations. Epidemiological studies may result in findings that allow measures to be taken to prevent similar events in the future. Attained findings

July 2004: flock of laying hens culled

Number of cases

30 20 10 0

0

0

0

0

0

0

0

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012

Year Figure 20: Human cases of S. Enteritidis phage type 36 in Austria, 2000-2012 42

0

Types of food-borne outbreaks

from successfully investigated national or international outbreaks in the last several years underscore the importance and necessity of epidemiological investigations.

Frequency of food-borne outbreaks in Austria In 2012, 122 food-borne outbreaks were detected. Compared to 2006, this corresponds to an 80 % reduction in outbreaks (tab. 2). 561 persons were affected by those outbreaks, with no deaths. The reduction of outbreaks caused by Salmonella since 2006 is very remarkable (nearly 90 %) and reflects the successful control program of Salmonella in laying hens. As seen in 2011, in 2012 the number of outbreaks caused by Campylobacter (n=61) exceeded the number of those caused by Salmonella. This fact was foreseeable; in 2006 the number of campylobacteriosis cases exceeded the number of salmonellosis cases (fig. 5). In 2012, outbreaks were also caused by norvirus, verocytotoxigenic E. coli and Listeria monocytogenes (twice each) and by hepatitis A virus and Entamoeba spp. (once each).

The national Zoonosis Act requires the AGES to annually collect outbreak data and subsequently report the date to the EU, using the following classifications: if all the human cases live in one single household, the outbreak is classified as a household outbreak; an outbreak involving human cases from more than one household is designated as a general outbreak. The majority of outbreaks are classified as household outbreaks; a single causative foodstuff or component associated with cases of several household outbreaks often cannot be identified. In 2012, 81 % of all outbreaks were classified as household outbreaks.

Food-borne outbreaks affecting people in more than one Austrian province, 2012 General outbreaks can include cases from different provinces, as described before in the S. Enteritidis PT36 outbreak that affected people from four provinces. If such an outbreak is suspected, often an expert from AGES is mandated to investigate the outbreak. In 2012, six outbreaks affecting more than one province were investigated. The largest outbreak, caused by

Table 2: Number of reported food-borne outbreaks in Austria, 2006-2012

Year

2006

2007

2008

2009

2010

2011

2012

Food-borne outbreaks

609

438

368

351

193

232

122

- caused by Salmonella

452

305

223

208

98

100

53

- caused by Campylobacter

137

108

118

120

82

116

61

2.530

1.715

1.376

1.330

838

789

561

493

286

338

223

155

179

97

3

1

0

6

2

0

0

Number of cases affected by an outbreak - number hospitalised - number of deaths

Salmonella Stanley, affected 147 cases from every Austrian province except Vorarlberg; turkey meat was identified as the vehicle. A norovirus outbreak, including 39 cases from Carinthia, Lower Austria, Salzburg, Styria and Vienna, was investigated; the most likely source were fruits, berries, fruit juice and other fruit products. Other smaller outbreaks included two caused by Listeria monocytogenes and one by Campylobacter coli. A Salmonella outbreak with four cases from three Austrian provinces was acquired in Italy; all Austrian cases stayed in the same hotel and were infected there. According to EFSA’s Manual on reporting of foodborne outbreaks, a distinction must be made between outbreaks with strong evidence and with absent or weak evidence. Only if the evidence implicating a food vehicle is strong a detailed outbreak dataset should be provided to the EU. For food-borne outbreaks where no particular food is suspected (i.e. there is no evidence) or where the evidence is weak, member states should report a limited, aggregated dataset.

Strong epidemiological evidence is a statistically significant association in a well-conducted analytical epidemiological study or convincing descriptive evidence. Strong microbiological evidence includes: identification of an indistinguishable causative agent (pathogen) in a human case and in a food, a food component, or its environment that is unlikely to have been contaminated following the event or coincidentally; or identification of a causative agent such as a toxin or bio-active amine in the food vehicle, in combination with clinical symptoms in outbreak cases that are consistent with the causative agent. In 2012, three outbreaks (2.5 %) with strong evidence were reported, including the previously mentioned outbreak caused by S. Stanley, a VTEC O113:H8 outbreak with three cases, and a S. Enteritidis PT8 outbreak affecting 67 cases. The VTEC O113:H8 outbreak strain was detected in frozen deer meat and the vehicle in the S. Enteritidis PT8 outbreak was broiler meat and related products imported from outside the EU.

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Austria and the EU compared: 2011 Reporting systems for food-borne outbreaks and investigation systems at national level are not harmonised among EU member states. Therefore, the differences in the number and type of reported outbreaks, as well as in the causative agents, may not necessarily reflect the level of food safety among member states; rather they may indicate, due to the sensitivity of national systems, differences in identifying and investigating food-borne outbreaks. In 2011, a total of 5,648 foodborne outbreaks, including outbreaks with both weak and strong evidence, were reported by 25 member states. As in Austria, the decline in the number of Salmonella outbreaks within the EU continued, from 1,888 outbreaks in 2008 to 1,501 outbreaks (26.6 %

Summary In 2012 a decline in food-borne outbreaks could be observed in Austria, after a slight increase in 2011 (tab. 2, fig. 21). As in 2011, the outbreaks caused by Campylobacter were most frequent (50 %), although fewer people (one-fourth of all cases) were affected by those outbreaks. This is consistent with international observations; Campylobacter outbreaks are usually reported as small household outbreaks. 65 % of all outbreak cases were caused by Salmonella (two large Salmonella outbreaks causing 214 cases). In 2012, among outbreak cases, no deaths were reported.

of all outbreaks) in 201112. Bacterial toxins, Campylobacter and viruses accounted for 12.9 %, 10.6 % and 9.3 % of the outbreaks, respectively. No causative agent was identified for more than 2,000 outbreaks (36 %) in the EU.

12

44

700 600

Number of outbreaks

17 outbreaks causing 37 cases, including the previously mentioned Italian hotel outbreak cases, were associated with travelling abroad.

500 400 300 200 100 0

2006

2007

2008

2009

2010

2011

2012

Year Figure 21: Number of reported food-borne outbreaks in Austria, 2006-2012 (source: Trends and Sources of Zoonoses, Zoonotic Agents and Food-borne Outbreaks in Austria, 2012)

From the European Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents and Food-borne Outbreaks in 2011, EFSA Journal 2013,11(4):3129 45


LIST OF NATIONAL REFERENCE CENTRES AND NATIONAL REFERENCE LABORATORIES INCLUDING CONTACT PERSONS13 National Reference Centre for Salmonella Institute for Medical Microbiology and Hygiene/Centre for Food-Borne Infectious Diseases Austrian Agency for Health and Food Safety 8010 Graz, Beethovenstrasse 6 Contact: Dr. Christian Kornschober National Reference Centre for Campylobacter/ National Reference Laboratory for Campylobacter Institute for Medical Microbiology and Hygiene/Centre for Food-Borne Infectious Diseases Austrian Agency for Health and Food Safety 8010 Graz, Beethovenstrasse 6 Contact: Mag. Dr. Sandra Jelovcan National Reference Centre and National Reference Laboratory for Brucella

Institute of Specific Prophylaxis and Tropical Medicine Medical University Vienna 1095 Vienna, Kinderspitalgasse 15 Contact: Univ.-Prof. Dr. Herbert Auer or Univ.-Prof. Dr. Ursula Wiedermann-Schmidt National Reference Laboratory for Trichinellosis in Animals Institute for Veterinary Disease Control, Innsbruck Austrian Agency for Health and Food Safety 6020 Innsbruck, Technikerstraße 70 Contact: Dr. Walter Glawischnig National Reference Centre for Tuberculosis

Institute for Veterinary Disease Control, Moedling

Institute for Medical Microbiology and Hygiene/Centre for Anthropogenic Infections

Austrian Agency for Health and Food Safety 2340 Moedling, Robert-Koch-Gasse 17 Contact: Dr. Erwin Hofer

Austrian Agency for Health and Food Safety 1096 Vienna, Währinger Straße 25a Contact: PD Mag. Dr. Alexander Indra

National Reference Laboratory for Listeria

National Reference Laboratory for Bovine Tuberculosis

Institute for Medical Microbiology and Hygiene/Centre for Food-Borne Infectious Diseases Austrian Agency for Health and Food Safety 8010 Graz, Beethovenstrasse 6 Contact: Mag. Dr. Ariane Pietzka

Institute for Veterinary Disease Control, Mödling Austrian Agency for Health and Food Safety 2340 Moedling, Robert-Koch-Gasse 17 Contact: Dr. Erwin Hofer

National Reference Centre for Listeria (Binational Consiliar Laboratory for Listeria (Germany/ Austria)

National Reference Centre and National Reference Laboratory for Escherichia coli including Verocytotoxigenic E. coli

Institute for Medical Microbiology and Hygiene/Centre for Anthropogenic Infections Austrian Agency for Health and Food Safety 1096 Vienna, Währinger Straße 25a Contact: Dr. Steliana Huhulescu

Institute for Medical Microbiology and Hygiene/Centre for Food-Borne Infectious Diseases Austrian Agency for Health and Food Safety 8010 Graz, Beethovenstrasse 6 Contact: Mag. Dr. Sabine Schlager

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National Reference Centre for Toxoplasmosis, Echinococcosis, Toxocariasis and other Parasitic Diseases

Information about all National Reference Centres and Laboratories according to article 3 of Commission Decision 2009/712/EG can be found on the homepage of the Federal Ministry of Health (http://bmg.gv.at) 47


HEALTH FOR HUMANS, ANIMALS AND PLANTS

Imprint Editor: Federal Ministry of Health

AGES - Austrian Agency for Health and Food Safety

Radetzkystr. 2

Spargelfeldstraße 191

1030 Vienna, Austria

1220 Vienna, Austria

www.bmg.gv.at

www.ages.at

Design & Layout: strategy-design Photos: BMG, AGES, fotolia © BMG & AGES September 2013 All Rights Reserved.


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