Bird flu at poultry farms, updates 2025/2026

Avian influenza (AI) is also known as bird flu. It is a collective term for several influenza viruses. Especially chickens, turkeys, waterfowl, waders, beach birds, ratites and starlings are susceptible to avian influenza. Avian influenza has two variants: a mild and a hazardous variant. Most viruses are of the mild variant; Low Pathogenic Avian Influenza (LPAI). Chickens infected with LPAI viruses exhibit few disease symptoms. However, LPAI viruses of types H5 or H7 can adapt (mutate) into a highly pathogenic variant; Highly Pathogenic Avian Influenza (HPAI). In chickens infected with HPAI viruses, very serious disease is seen, with up to 100% mortality.

Some types of bird flu are transmissible to humans (zoonosis). The chance of humans becoming infected is small, and if it does happen the symptoms are usually very mild. However, it is important to prevent infections as much as possible. The bird flu virus could adapt itself (by mutation), after which it could also spread between people. Therefore we strongly advise to avoid direct contact with sick and dead wild birds and poultry.

Avian influenza is transmitted by infected wild (water) birds and their faeces. The risk for poultry that can roam outside is therefore much higher. As more and more poultry is kept in free-range conditions, the risk of bird flu in the Netherlands will increase. The (illegal) import of ornamental birds also constitutes a risk. The risk of bird flu entering the Netherlands via the import of poultry, hatching eggs and poultry products is probably small. A monitoring programme for avian influenza in the Netherlands is running, so that we can quickly trace new introductions.

Birds, including poultry, can catch bird flu in several ways:

• Through direct contact with infected birds or faeces; the virus can be spread through the respiratory system, eye fluids and droppings
• Through contaminated materials such as food, crates, vehicles and people who have been in contact with the virus through their shoes or clothing
• Via dust from a contaminated coop (spread through the air)

It is impossible to prevent the infection of wild birds. However, farmers can take a large number of measures to decrease the risks of potential contamination. The virus can be kept from affecting stables by putting in place bio-safety measures. Implementing and following up these measures requires perseverance and strict discipline. Businesses such as breeding farms that are higher up in the pyramid, generally invest more in bio-safety. These companies are seldom affected by avian flu.

Within the European Union legislation exists to prevent avian influenza from being introduced or spread via infected poultry or transport.

Vaccination of poultry is possible but there are many snags to it.