Analysis of zoonotic mutations of avian influenza viruses

Avian influenza viruses (AIVs) pose a global health risk for animals and humans with outcomes ranging from asymptomatic cases to fatalities. In recent years, HPAI were detected in several mammal species globally including minks in Spain, marine mammals in South America, cats in Poland, and seals along the North Atlantic coast. The H5N1 outbreak in U.S. dairy cattle marked the first detection of HPAI in this species. Although human-to-human transmission has not been clearly demonstrated so far, this scenario raises epidemiological concerns, particularly due to the ability of AIVs to adapt and infect mammalian hosts. Close monitoring of genomic sequences and mutations is essential to quickly identify markers that affect host range or virulence, potentially leading to spillover in mammals with possible harmful effects. Efficient evaluation of AIV risks requires the analysis of mammalian adaptation markers and the screening of genomic sequences. To enhance pandemic preparedness measures and to understand the evolution of AIVs, a total of 592 potential zoonotic markers across eight viral segments were identified from a literature review and screened in over 1.4 million sequences from available public databases. From these inputs, mutation frequencies were observed within avian and mammalian hosts, including humans, per geographical area, and per period, generating a database composed of a total of 1,974 spreadsheets. The present report updates the list of potential zoonotic markers and provides an overview of their frequency in avian and mammalian populations, including humans. It serves as the basis for future in-depth investigations to assess the zoonotic risks associated with avian influenza viruses and to develop a comprehensive risk assessment