26 June 2026
Hungary reported the detection of the A(H9N2) clade G5.5 virus in April in seven establishments keeping broiler chickens, all located within a single geographical area in the same settlement. Increased mortality in one establishment initially raised suspicion of HPAI; however, the birds tested negative for A(H5) and A(H7) HPAI viruses. Testing for infectious bronchitis virus (IBV) yielded positive results, and pathological examination revealed tracheitis, indicating a clinical presentation consistent with co-infection. This finding prompted additional testing for the A(H9N2) virus.
As this particular clade had previously been restricted to countries outside the European Union, including those in the Middle East, poultry workers were interviewed regarding their travel history. However, no plausible epidemiological link could be established, and the source of introduction remained unknown at the time of reporting.
All affected establishments were depopulated, cleaned, and disinfected. Following repopulation, the birds will be retested for A(H9N2) virus after 2–3 weeks. Waterfowl flocks in the affected county were also tested for A(H9) virus prior to movement, and all results were negative.
Source: EFSA/ECDC
