Current trends in mammalian infection patterns with HPAIv H5N1
A comprehensive review of mammalian infections during the current panzootic period (2020-2023), compared to previous waves of infection (2003-2019), was recently published in EID. It highlights the expanded geographic reach and increased number of species affected by the current event, emphasizing the importance of continuous surveillance to mitigate the risk of a global pandemic.
During the current panzootic period (2020-2023), the virus has affected a larger number of mammalian species worldwide compared to previous waves of infection. The current panzootic event has impacted a variety of mammalian species, including those classified as near-threatened, endangered, vulnerable, and critically endangered, potentially exacerbating their conservation status. The most likely source of mammalian infection appears to be close contact with infected birds, with some evidence suggesting potential mammal-to-mammal transmission.
The main mutations that confer efficiency to the highly pathogenic avian influenza A(H5N1) virus in the replication process within mammals include:
PB2-E627K: This mutation is commonly associated with virulence and efficiency in the replication of the H5N1 virus in mammalian hosts.
PB2-D701N: Another mutation in the PB2 gene, PB2-D701N, has also been found to enhance the replication of the H5N1 virus in mammalian cells. These mutations are significant as they may facilitate the adaptation of the H5N1 virus to replicate more efficiently in mammalian hosts, potentially increasing the risk of mammal-to-mammal transmission and posing a greater threat to both wildlife and human health. Monitoring these mutations is crucial for understanding the evolution and spread of the virus and for assessing the risk of a potential pandemic.
