Deadly Avian Influenza Outbreak! 11 Countries Affected, Human Cases Surge to 19, New Strain of Virus Emerges

From 15 June to 20 September 2024, a total of 11 European countries experienced concentrated outbreaks of highly pathogenic avian influenza (HPAI). As of September 20, 2024, there have been six confirmed cases of A (H5N1) virus and five confirmed human cases of A (H5) virus infection in the United States. Five cases of A (H5N1) infection have been reported in Cambodia; China has reported 1 human case of A H5N6 and 1 human case of A H9N2 infection. In addition, Ghana has reported one case of A (H9N2) virus infection. For the general population in the EU/EEA, the risk of infection is assessed as low grade, while for occupationally exposed populations, the risk of infection is judged to be in the low to moderate range.

During the outbreak, A total of 75 cases of highly pathogenic avian influenza (HPAI) A (H5) and A (H7) viruses were detected in samples from 16 poultry and 59 wild animals in 11 countries in the European region. Although the overall number of detections in Europe remains low compared to epidemiological data from previous years, it is worth noting that there has been a significant increase in the number of cases reported in the Atlantic, North Sea and Baltic coastal regions, and in particular an increase in the number of highly pathogenic avian influenza viruses detected in cluster-breeding seabirds. In addition to EA2022BB and other popular genotypes, the test also identified for the first time a new genotype, EA2023DT, that may be more efficient in seagulls. In particular, the HPAI A (H7N5) virus has also been detected on a German poultry farm near the Dutch border.

In addition, no new highly pathogenic avian influenza viruses were reported in mammals in the European region during this period. In the United States, however, the number of affected dairy farms has grown to more than 230 in 14 states, and highly pathogenic avian influenza viruses have been detected for the first time in three new mammal species. Specifically, from June 21 to September 20, 2024, A total of 19 new human cases of avian influenza virus infection have been reported in the United States (6 A (H5N1) and 5 A (H5) cases), Cambodia (5 A (H5N1) cases including 1 death), China (1 A (H5N6) death and 1 A (H9N2) case) and Ghana (1 A (H9N2) case). Of these, the vast majority of human cases (90%, or 17/19) had a history of contact with poultry, live poultry markets or dairy cows prior to infection or illness.

It is worth emphasizing that human infection with the avian influenza virus remains extremely rare, and no clear evidence of human-to-human transmission was found during the reporting period. For the general public in the European Union/European Economic Area (EU/EEA), the risk of infection with the 2.3.4.4b Clade A (H5) avian influenza virus currently circulating in Europe remains low. For those who may be exposed to infected animals or contaminated environments for occupational or other reasons, the risk continues to be assessed as low to moderate.