Changes to the version dated 9 April 2024: Addition of new findings on the transmission of the bird flu virus from infected cattle to humans through contact with the animals and consumption of milk and meat
Concerned persons are asking whether poultry, poultry products or other foods such as cow’s milk can become contaminated with the bird flu virus (various subtypes of the avian influenza virus including H5N1 and H5N8). Here, the German Federal Institute for Risk Assessment (BfRshort forGerman Federal Institute for Risk Assessment) provides answers to these questions.
Generally, the transmission of the pathogen via infected food cannot be ruled out. However, infections of humans with the bird flu virus are rare, and direct and close contact with infected birds or other animal species appears to be the main transmission route to humans. The BfRshort forGerman Federal Institute for Risk Assessment does not have any data verifying that humans have been infected and became ill after ingestion of food that was contaminated with the bird flu virus.
As the virus is sensitive to high temperatures, no adverse health effects are to be expected if the food has been well cooked. Meat is considered well-cooked if all sides and the core reach a temperature of at least 70 °Cshort fordegrees Celsius for 2 minutes. This is evident when the poultry meat is no longer red or pink and no red juices are leaking out.
So far, there is no evidence suggesting that humans can be infected by raw eggs or raw sausage products containing poultry meat from infected animals. However, it has been proven that eggs of infected animals can contain the virus both on the shell and also in the egg white and yolk. As a precaution, anyone who wants to protect themselves against bird flu viruses and other pathogens that are possibly present in eggs and egg products should not consume raw egg products (whipped egg whites, tiramisu, etc.). The egg white and egg yolk of boiled eggs should be solid.
The consumption of pasteurised milk from cattle possibly infected with the bird flu virus is not expected to have any adverse health effects, as the virus - like other pathogenic microorganisms - is efficiently inactivated by heating.
[Accordion] Selected questions and answers relating to hygiene of food and consumables in times of the bird flu – How can I protect myself and my family?
The highly pathogenic avian influenza (bird flu, classical fowl plaque) is a disease that is highly infectious for birds and poultry, and these hosts suffer from serious disease courses. Bird flu is caused by various subtype A strains of avian influenza virus, including the subtypes A(H5N1), A(H5N6), A(H5N8) and A(H7N9), that can also cause serious illness among humans in some cases.
The subtype A(H5N1) has also been found in mammals, including in mink, cats, and sea lions. Since 2024, the virus has been spreading among cattle in the United States, too, where it predominantly causes udder infections.
The BfRshort forGerman Federal Institute for Risk Assessment provided more information about the subtype H5N1 in 2004 at
and about subtype H5N8 in 2021 at
Further information is available on the websites of the Friedrich Loeffler Institute (External Link:www.fli.de), the Robert Koch Institute (External Link:www.rki.de), and the Federal Ministry of Food and Agriculture (External Link:www.bmel.bund.de).
There is more information about the latest spread of bird flu on the homepage of the Food and Agriculture Organization of the United Nations (FAO) at External Link:https://www.fao.org/animal-health/situation-updates/en and the World Health Organization (WHO), at External Link:https://www.who.int/health-topics/influenza-avian-and-other-zoonotic#tab=tab_1.
The US Animal and Plant Health Inspection Service provides information regarding the spread of H5N1 virus in cattle and humans in the United States (External Link:https://www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influenza/hpai-detections/hpai-confirmed-cases-livestock) as well as the Centers for Disease Control and Prevention (External Link:https://www.cdc.gov/bird-flu/spotlights/).Since March 2024, cases of H5N1 infection in cattle have been reported in several US states. In this context, a few H5N1 infections have also been detected in humans with close contact to the diseased cattle. The infected persons showed light signs of illness, predominantly conjunctivitis and low-grade respiratory symptoms. As of yet, there is no evidence of human-to-human transmission.
In diseased cattle, the involved virus strain is similar to a strain that is currently widespread worldwide, particularly in wild birds. In the USA, the virus was detected in milk samples and swab samples from the mouth and throat of sick cattle. The disease in cattle was mainly characterised by temporary fever, lethargy, reluctance to eat and a drop in milk yield. In cattle, the virus multiplies mainly in the udder and transmission of the virus between cattle appears to occur predominantly through the udder and contaminated milking equipment.
Outside of the USA, no evidence of H5N1 infections in cattle have been found to date. No H5N1 virus has been detected in milk samples from German cattle (External Link:https://www.fli.de/de/aktuelles/kurznachrichten/neues-einzelansicht/gefluegelpest-keine-hinweise-auf-h5n1-infektionen-bei-milchkuehen-ausserhalb-der-usa/).
According to the reports from the USA, the virus was also detected in in milk samples from sick cattle. The virus was also detected in commercially available pasteurised milk in the United States, although the virus was no longer infectious. It is not yet known whether humans can become infected by consuming H5N1-contaminated milk. However, previous human H5N1 infections were mostly due to close contact with sick animals or their excrements. The consumption of pasteurised milk from cattle possibly infected with the bird flu virus is not expected to have any adverse health effects, as the virus - like other pathogenic micro-organisms - is destroyed by heating. Nevertheless, milk from infected animals should not be sold. Raw milk should generally be heated before consumption, also to protect against other pathogens that may be present.
The virus was detected in the lean meat of an infected cow; no evidence of virus transmission through consumption of raw beef or beef products from infected animals has been found so far. Using burger patties artificially contaminated with virus, it has also been shown that cooking them to be “well-done” or “medium” completely inactivates the virus.Based on the current knowledge, direct contact with poultry is the most important transmission route of the virus between poultry and humans. There is only little known about virus transmission by the consumption of raw poultry meat products from infected animals. However, with respect to the preventive consumer protection, care should be taken to comply with hygiene rules when handling or preparing raw poultry meat and poultry meat products. As the virus is highly sensitive to high temperatures, no adverse health effects are to be expected if the food has been well cooked. Meat is considered well-cooked if all sides and the core reach a temperature of at least 70 °Cshort fordegrees Celsius for 2 minutes. This is evident to consumers when the poultry meat is no longer red or pink and no red juices are leaking out.
In the case of eggs or egg products, it is possible to protect against these viruses and other possibly present pathogens by avoiding the consumption of raw egg products (whipped egg whites, tiramisu etc.), and by ensuring that the egg white and yolks of boiled eggs are solid.
Humans should avoid contact with wild birds. This particularly applies for died animals and for regions in which the bird flu virus was detected in dead wild birds. Visitors to countries in which the bird flu is widely distributed among poultry flocks should avoid direct contact with poultry and their excretions. It is advised to refrain from visiting poultry markets of poultry farms. Import bans on poultry or other birds, poultry meat, eggs and other poultry products, or feathers or untreated hunting trophies from affected countries into the European Union should always be observed to prevent further outbreaks of bird flu in domestic commercial livestock. When preparing poultry meat and raw eggs, the general hygiene regulations should be observed:
- Store and prepare raw poultry products and other food separately, especially if the latter is not reheated.
- Thoroughly clean equipment and surfaces that have come into contact with raw poultry products with warm water and detergent.
- Dispose of packaging materials, thawing water and similar immediately.
- Wash hands with warm water and soap.
- Cook poultry meals thoroughly. This means that all areas, even the core, must have reached a temperature of at least 70 °Cshort fordegrees Celsius for 2 minutes.
- In the case of eggs or egg products, it is possible to protect against these viruses and other possibly present pathogens by avoiding the consumption of raw egg products (whipped egg whites, tiramisu etc.), and by ensuring that the egg white and yolks of boiled eggs are solid.
In countries where the virus has also been detected in cattle, close contact with infected animals should be avoided. Raw milk should generally be heated before consumption, also to protect against other pathogens that may be present.
Surface water from waters with large populations of wild birds may, in principle, be contaminated with bird flu viruses. It should not be used as drinking water for breeding and commercial poultry if it has not been appropriately treated.
Drinking water in Germany is primarily collected from deep wells. This guarantees a high level of safety regarding microbiological risks. Wherever drinking water is collected from surface waters, complex technical procedures are used that comply with the tolerances and requirements of the Drinking Water Regulations. This reliably rules out contamination of drinking water with bird flu viruses. The German Federal Office for Environment provides more information about drinking water (External Link:https://www.umweltbundesamt.de/themen/wasser/trinkwasser).
The code number of the packing point must be stated on egg cartons. This may also contain information about the origin of the eggs. The eggs themselves bear the country code of the country of origin.
Poultry meat sold in retail shops bears the approval number of the slaughterhouse or meat processing facility, and poultry meat that was imported from non-EU countries the country of origin, on the packaging or label.
There are relevant legal regulations that govern the import and the trade of live poultry from livestock populations and their products. There are more recommendations about hygienic handling of poultry meat on the websites of the German Federal Institute for Risk Assessment (External Link:www.bfr.bund.de).
Down is washed during production and then dried at 100 °Cshort fordegrees Celsius. Influenza viruses are very sensitive to heat and to the detergents used in soaps and washing agents. Based on the current knowledge, the methods used to produce down also inactivate bird flu viruses so that they are no longer infectious. An infection with the bird flu virus through objects that contain feathers or down is therefore very unlikely.