First Human Infection of Avian Influenza A(H5N6) Virus Reported in Lao People’s Democratic Republic, February-March 2021

In March 2021, Lao People’s Democratic Republic (Laos) reported an avian influenza A(H5N6) virus infection in a 5-year-old child identified through sentinel surveillance. This was the first human A(H5N6) infection reported outside of China. A multidisciplinary investigation undertook contact tracing and enhanced human and animal surveillance in surrounding villages and live bird markets. Seven Muscovy ducks tested positive for highly pathogenic avian influenza A(H5N6) viruses. Sequenced viruses belonged to clade 2.3.4.4h and were closely related to viruses detected in poultry in Vietnam, and to previous viruses detected in Laos. Surveillance and coordinated outbreak response remain essential to global health security.

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First human infection of avian influenza A(H5N6) virus reported in Lao People's Democratic Republic, February–March 2021

Influenza and Other Respiratory Viruses ◽

10.1111/irv.12934 ◽

2021 ◽

Author(s):

Bounthanom Sengkeopraseuth ◽

Kim Carmela Co ◽

Phetdavanh Leuangvilay ◽

Joshua A. Mott ◽

Boungnasith Khomgsamphanh ◽

...

Keyword(s):

Avian Influenza ◽

Influenza A ◽

Democratic Republic ◽

Human Infection ◽

Lao People’S Democratic Republic ◽

Lao People's Democratic Republic

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Genetic Characterization of Highly Pathogenic Avian Influenza A(H5N8) Virus in Pakistani Live Bird Markets Reveals Rapid Diversification of Clade 2.3.4.4b Viruses

Viruses ◽

10.3390/v13081633 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1633

Author(s):

Muzaffar Ali ◽

Tahir Yaqub ◽

Muhammad Furqan Shahid ◽

Foong Ying Wong ◽

Nadia Mukhtar ◽

...

Keyword(s):

Avian Influenza ◽

Influenza A ◽

Virus Detection ◽

Human Infection ◽

Economic Losses ◽

Influenza Surveillance ◽

Highly Pathogenic ◽

Live Bird Markets ◽

Domestic Poultry ◽

Live Bird

The highly pathogenic (HPAI) avian influenza A(H5N1) viruses have undergone reassortment with multiple non-N1-subtype neuraminidase genes since 2008, leading to the emergence of H5Nx viruses. H5Nx viruses established themselves quickly in birds and disseminated from China to Africa, the Middle East, Europe and North America. Multiple genetic clades have successively evolved through frequent mutations and reassortment, posing a continuous threat to domestic poultry and causing substantial economic losses. Live bird markets are recognized as major sources of avian-to-human infection and for the emergence of zoonotic influenza. In Pakistan, the A(H5N1) virus was first reported in domestic birds in 2007; however, avian influenza surveillance is limited and there is a lack of knowledge on the evolution and transmission of the A(H5) virus in the country. We collected oropharyngeal swabs from domestic poultry and environmental samples from six different live bird markets during 2018–2019. We detected and sequenced HPAI A(H5N8) viruses from two chickens, one quail and one environmental sample in two markets. Temporal phylogenetics indicated that all novel HPAI A(H5N8) viruses belonged to clade 2.3.4.4b, with all eight genes of Pakistan A(H5N8) viruses most closely related to 2017 Saudi Arabia A(H5N8) viruses, which were likely introduced via cross-border transmission from neighboring regions approximately three months prior to virus detection into domestic poultry. Our data further revealed that clade 2.3.4.4b viruses underwent rapid lineage expansion in 2017 and acquired significant amino acid mutations, including mutations associated with increased haemagglutinin affinity to human α-2,6 receptors, prior to the first human A(H5N8) infection in Russian poultry workers in 2020. These results highlight the need for systematic avian influenza surveillance in live bird markets in Pakistan to monitor for potential A(H5Nx) variants that may arise from poultry populations.

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