Highly pathogenic avian influenza (HPAI) H5N1 continues to pose a significant threat to animal health, poultry production, and public health worldwide. Mali experienced two outbreaks of Highly Pathogenic Avian Influenza (HPAI) H5N1 in 2021 and 2022, raising concerns about viral evolution and potential public health risks in West Africa. Suspected samples (Tissue and swab) collected from sick and dead birds during these outbreaks were analyzed at the Central Veterinary Laboratory of Bamako using quantitative real-time PCR. Whole-genome sequencing was performed on thirteen H5N1-positive samples using the Illumina MiSeq platform with a paired-end sequencing approach. Phylogenetic analyses were conducted using the maximum-likelihood method implemented in IQ-TREE v1.6.6. Phylogenetic analysis of the hemagglutinin (HA) gene revealed that all detected viruses belonged to clade 2.3.4.4b and clustered closely with strains previously reported in West Africa. In-depth analysis of the whole genome phylogenetic topology revealed the emergence of an H9N2/H5N1 reassortant strain during the 2022 outbreak. Molecular characterization of all eight genomic segments identified several mutations associated with host specificity, including markers linked to adaptation in gallinaceous poultry and mutations potentially associated with increased zoonotic potential. These findings demonstrate the continued genetic evolution of H5N1 viruses circulating in Mali and emphasize the importance of sustained genomic surveillance. Strengthening hygiene practices and biosecurity measures in poultry farms, live bird markets, and slaughterhouses is essential to reduce the risks posed to both animal and public health.
Adama Diakite, M. Diakité, F. Dembele et al.· International Journal of Mic...· 0 citations
ABSTRACT Background H5Nx goose/Guangdong (Gs/GD) lineage highly pathogenic avian influenza (HPAI) viruses pose a significant public health threat due to their global spread, mutation accumulation, and expanding host range. The descendant clade 2.3.4.4b has been causing widespread infections in birds and increasing spillover events in mammals. Methods This report documents the first fatal case of highly pathogenic avian influenza virus (HPAIV) H5N1 clade 2.3.4.4b infection in a domestic cat in Italy, detected in early January 2025. The cat (CAT 1) resided on a backyard poultry farm experiencing a high pathogenicity avian influenza outbreak and succumbed rapidly following the onset of respiratory signs. A second exposed cat (CAT 2) developed clinical disease without fatal outcome. Comprehensive outbreak investigations were conducted, including pathological, serological, molecular analyses, and genomic characterization. Results Pathological examination of CAT 1 revealed acute necrotizing bronchointerstitial pneumonia, non‐suppurative meningoencephalitis, and disseminated foci of hepatic necrosis. Interestingly, the PB2‐E627K mutation associated with mammalian virus adaptation was observed in the feline viral isolate compared to avian isolates. Such polymerase complex mutations are key determinants of host range and increase pathogenicity in mammals. CAT 2 from the same farm tested negative for AIV genome detection but subsequently seroconverted for antibodies against NPA, H5, and N1. Conclusion Sharing these findings is crucial for surveillance aimed at enabling early identification of increased risks to human and animal health, preventing cross‐species viral transmission and mitigating the risk of potential spillover events.
G. D’Annunzio, Ana Moreno, Giovanni Tosi et al.· Influenza and Other Respirat...· 0 citations
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