Avian influenza in humans: Annual Epidemiological Report for 2022
Avian influenza virus A(H3N8)
In 2022, China reported two children infected with avian influenza virus A(H3N8) reassortant virus – both children were exposed to live poultry before the onset of symptoms. These are the first two cases of human avian influenza A(H3N8) globally.
Avian influenza virus A(H5N1)
In 2022, six human cases with avian influenza virus A(H5N1) were reported globally. In Europe, Spain detected viral fragments of A(H5N1) in specimens taken from two asymptomatic poultry workers involved in culling and cleaning activities during an avian influenza outbreak at the same farm. However, productive infection was ruled out, and a contamination was considered. Similarly, in the US, a low level of viral fragments was detected in a worker identified with mild symptoms (fatigue), who was involved in culling activities. One lethal case of an individual exposed to backyard poultry was reported by China. One human infection with avian influenza virus A(H5N1) was reported in Vietnam, in a five-year-old girl exposed to sick poultry. For the first time, an avian influenza virus infection was reported in South America: a nine-year-old girl developed severe symptoms following exposure to sick and dead backyard poultry in Ecuador.
Avian influenza virus A(H5N6)
In 2022, 18 human cases of avian influenza virus A(H5N6) were reported from China, including three deaths. All the cases were exposed to infected poultry or virus-contaminated environments, such as live poultry markets. However, the source of exposure is unknown for one case.
Avian influenza virus A(H9N2)
In 2022, 16 human cases of avian influenza virus A(H9N2) were reported globally. Out of these, 15 were reported from China (one adult, and the remaining children). Among the cases with known exposure, all the infected individuals were exposed to poultry. In addition, Cambodia reported one case of avian influenza virus A(H9N2) in a one-year-old female with exposure to backyard poultry. Avian influenza virus A(H10N3)
One human case of avian influenza virus A (H10N3) was reported from China in 2022, following exposure tobackyard poultry. This was the second human case of avian influenza virus A (H10N3), after the first reported from China in 2021.
