Avian influenza A H5N1 viruses have transmitted in some instances from animal to human and they can cause flu-like symptoms, which can lead to serious complications. Close virological surveillance is important to identify the possibility of human transmission early.
Situation in Switzerland
A number of cases of highly pathogenic avian influenza (HPAI) have been reported among domestic and wild birds in Switzerland. The Federal Food Safety and Veterinary Office (FSVO) is monitoring the situation on an ongoing basis. In November 2022, the FSVO declared the whole of Switzerland a control area with heightened security regulations and initiated corresponding measures. Further information on the disease among animals and countermeasures is available on the FSVO website.
There have to date been no laboratory-confirmed cases in Switzerland of human infection with H5N1.
International situation
The avian flu virus H5N1 is spreading among farmed and wild birds in large areas of Europe. In recent times, mammals are often affected as well. Cases globally comprising people were reported to the WHO since 2003, including fatalities. You can find further information on the international situation on the WHO page.
Pathogen and transmission
The influenza A H5N1 virus can be transmitted to humans through contact with infected farmed or wild birds, and potentially with infected mammals. Direct airborne transmission is possible (respiratory secretions, dust) as well as indirect transmission through contaminated hands coming into contact with the eyes, nose and mouth.
The Federal Office of Public Health (FOPH) rates the risk of infection for the general public as low based on the assessments of the WHO and European Centre for Disease Prevention and Control (ECDC). The infection risk is low to medium for occupationally exposed persons, whereby this risk may differ depending on the type of bird or mammal and the circulating avian flu virus. Persons most at risk of infection are those who come into close contact with farmed and/or wild birds. There is no evidence to date of sustained human-to-human transmission or the spread of avian flu among people.
Clinical picture/treatment
Initial symptoms usually occur 2 to14 days after coming into contact with an infected animal. The flu-like symptoms can manifest themselves in different degrees of severity. Infected persons are treated with antiviral medication. There is currently no vaccine approved for people against a current strain of the H5N1 influenza subtype. The FOPH is, however, monitoring the development of such vaccines.
Recommendation
- The public are advised not to touch sick or dead animals found outdoors. If they do come into contact with such animals, they are advised to disinfect their hands or wash them thoroughly with soap and water. Please report dead animals to the cantonal veterinary services (page available in German or French) or to the relevant cantonal office of the Conference of Chiefs of the Environmental Protection Office of Switzerland (page available in German, French or Italian)
- People who work with or otherwise regularly come into contact potentially infected poultry or birds held in captivity, or who encounter potentially infected mammals, such as foxes or other wild animals, are to take appropriate protective measures. The FSVO provides details on protective measures, such as hand disinfection, on its website (page available in German, French or Italian).
- People must check for potential symptoms following unprotected contact with birds, especially sick birds or sick mammals.
If flu-like symptoms occur, contact a doctor and refer to the contact with farmed and/or wild birds.
Measures
Doctors are obliged to notify any suspected cases of a new influenza subtype in people, H5N1 for example, by telephone within two hours. The infected person may be isolated depending on the circumstances.
Last modification 09.10.2023
Contact
Federal Office of Public Health FOPH
Division Communicable diseases
Schwarzenburgstrasse 157
3003
Bern
Switzerland
Tel.
+41 58 463 87 06