In its weekly update on avian influenza, the Hong Kong Centre for Health Protection (CHP) has reported 2 new cases of H9N2 virus infection in China. The two girls, aged one, hail from the neighbouring provinces of Guizhou and Guangxi. Their symptoms and health conditions remain unknown. The source of infection is also unclear, though exposure to infected poultry is suspected. The total number of human cases in 2024 now stands at 15, with most cases occurring in children under ten.
The threat that avian influenza viruses pose to public health is heightened by the possibility of these pathogens accumulating mutations and exchanging genes with other viruses that infect humans, including those of the H9N2 subtype. A recent study published in the scientific journal Nature Communications has revealed that most H9N2 viruses currently circulating in China exhibit a high affinity for human cells, comparable to that observed in human influenza viruses. This finding may explain the rising number of human H9N2 infections reported in the country. A further consequence of this scenario would be the possibility of avian influenza viruses adapting to humans, enabling them to transmit from person to person, as supported by recent findings published in the scientific journal Science.
