Information on zoonoses

What are zoonoses?

Zoonoses are infectious diseases that can be transmitted naturally, directly or indirectly between vertebrates and humans.

What are the zoonotic pathogens?

Among all pathogenic agents (viruses, bacteria, parasites, fungi or prions) that are possible for humans and animals, we find those that have zoonotic potential. More than half of all pathogenic (= disease-causing) species for humans (species, such as Hepatitis E Virus, Campylobacter jejuni, Toxoplasma gondii Echinococcus multilocularis) can be transmitted between humans and animals, and many of them can also cause disease in animals.

Which are or were significant zoonotic diseases?

rabies, tuberculosis and plague, as well as numerous food-borne diseases such as salmonellosis or campylobacteriosis , and diseases transmitted by so-called vectors, such as mosquitoes or ticks, such as malaria or early summer meningoencephalitis (TBE).

How are zoonotic pathogens transmitted?

Zoonotic pathogens can be transmitted directly through contact with the diseased animal (bite wound: e.g., rabies virus) or a healthy animal colonized with a zoonotic pathogen (petting zoo: e.g., VTEC, skin fungi); indirect transmission is also possible, through consumption of contaminated food (e.g. e.g. raw eggs - Salmonella, raw milk - Campylobacter or VTEC, fallen fruit from meadow fertilized with cow manure - VTEC, meat - Toxoplasma, or polluted surface water - Campylobacter). If mosquitoes or ticks function as intermediate hosts or vectors, West Nile fever virus or Borrelia can be passed on.

How can I protect myself from zoonotic pathogens?

I can protect myself well from zoonotic pathogens by knowing the possible transmission routes and interrupting them. Since there are many ways of transmission, which make use of the different pathogens, only basic measures can be addressed here, the details are listed with the individual pathogens.

  • After each animal contact, or work in the garden, especially before eating, hands should be washed thoroughly with soap.
  • Wash plant foods carefully before eating them.
  • Avoid eating raw food - this applies especially to persons with increased risk, such as pregnant women, small children, immunosuppressed or elderly persons.
  • Vaccinations are available against many infectious diseases, such as rabies or TBE, which can be used to protect yourself.
  • In mosquito areas, loose clothing and repellents protect against possible bites, especially during the active period of the insects, preventing the transmission of possible pathogens
  • To protect humans, food-producing livestock are vaccinated against zoonotic pathogens, for example (laying hens against salmonella), and animals, before and after slaughter, are officially inspected (official meat inspection) and randomly sampled for certain zoonotic pathogens.

Monitoring and control of zoonoses and zoonotic agents

In order to be able to evaluate and assess hazards posed by possible (over-)carriers of zoonotic pathogens and to combat them in a targeted manner in order to protect humans from such diseases, data on the occurrence of zoonotic pathogens along the entire food chain from the environment, farm animals and food production to consumers are obtained on an ongoing basis. For example, mosquito traps are set up so that captured insects can be identified and tested for pathogenic viruses. Surveillance programs for zoonotic pathogens are conducted in a coordinated manner at the national level, but also across the EU and internationally. Successful surveillance and control strategies in the 2nd half of the 20th century have resulted in Austria achieving official "recognized free" status for certain zoonotic animal diseases (e.g. bovine tuberculosis, bovine brucellosis or Brucella melitensis infections in small ruminants). To maintain this officially recognized disease-free status, control programs must continue to be carried out annually in accordance with EU requirements.

As a center for foodborne infectious diseases, we play an essential role in identifying pathogens and clarifying disease outbreaks caused, for example, by Listeria or Salmonella. In our reference centers, we use state-of-the-art technology such as whole-genome sequencing to determine the genetic fingerprint of a wide variety of pathogens. Every year, we examine thousands of isolates from human, food, feed, veterinary and environmental samples.

When comparing over the years, the sharp decline in Salmonella is striking: This decline in human salmonellosis was almost entirely due to the decline in S. Enteritidis infections. Since 2006, Campylobacter has ranked first among reported foodborne bacterial infectious diseases. Campylobacter infections cluster during the warm season; the fewest cases of illness between November and April, and the most cases between June and September. The reverse is true for noroviruses, one of the most common causes of virus-related infections of the gastrointestinal tract: typically, the norovirus season begins in October and continues through April.

Yersinia(Y. enterocolitica) is the third most common bacterial zoonotic pathogen in the EU. Similar to Listeria, Yersinia can also multiply on contaminated food in the refrigerator. Although illnesses caused by Listeria are rare, they are often fatal. The increase in STEC cases since 2016 is primarily due to the increased use of culture-independent detection methods in laboratories, which means more patient:in samples are also being tested for STEC. A large proportion of all illnesses caused by shigella in Austria are imported by travelers (around 60-70% of reported cases), with the pathogens most frequently being imported from Egypt, India and Morocco.

Pathogen detections over the past years

Joint strategy for the control of zoonoses in the EU and worldwide

In zoonoses monitoring, data on the occurrence of zoonotic pathogens along the entire food chain, from the environment, farm animals and food production to consumers, are continuously obtained across the EU. The so-called One Health approach is based on the understanding that human, animal and environmental health are intertwined. Therefore, the One Health approach serves prevention and promotes interdisciplinary cooperation, especially between human medicine, veterinary medicine and environmental sciences. Across the EU, monitoring and surveillance programs for zoonotic agents along the food chain have been harmonized in recent years, systems for standardized data collection have been created, and consensus has been reached on the most important agents to be monitored. The disease figures of zoonotic agents reported by the Member States to the European Centre for Disease Prevention and Control (ECDC) and the results of the monitoring, surveillance and control programs along the food chain to the European Food Safety Authority (EFSA) are published at least once a year in a joint European One Health Zoonoses Report and made available to the expert community and all interested persons.

Reports on the occurrence of zoonoses

Many countries publish annual national reports on their situation regarding zoonotic pathogens. In Austria, until 2018, annual reports on "Zoonoses and their pathogens in Austria" were presented in printed form and online jointly by the Federal Ministry of Social Affairs, Health, Long-Term Care and Consumer Protection (BMSGPK) and AGES. Since 2019, the annually collected Austrian data are described electronically on the AGES website under the respective pathogens .

The European Food Safety Authority (EFSA), together with the European Centre for Disease Prevention and Control (ECDC), collects the national reports of the EU Member States and uses them to produce the joint "European Union One Health Zoonoses Report". The latest version currently available is "The European Union One Health 2021 Zoonoses Report". The national reports of all Member States with the corresponding veterinary, food and agricultural data and foodborne outbreak surveys submitted to EFSA and from which the EUOHZ was compiled are available on the EFSA website.

Reference centers of zoonotic pathogens

Last updated: 18.01.2023

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