#19,235
Nestled between India and China, Nepal is no stranger to HPAI H5N1 - including at least 1 human case in 2019 - along with sporadic outbreaks in poultry over the years.
In recent months, however, FluTrackers has been following an increasing number of reports of outbreaks in both wild birds and poultry.
Since early March, WOAH reports 66 outbreaks across the country, involving the loss of more than 500,000 domestic birds, and reports of die offs of wild birds (mostly wild house crows).
While official government reports are infrequent and hard to access, local and international media have reported increasing concern over the spread of H5N1 in Nepal, with Nepal News reporting yesterday (Jul 4th) Health Ministry issues nationwide alert over spreading bird flu outbreak.
Ministry Joint Spokesperson Samir Mani Adhikari is quoted as urging `. . . the public to completely avoid direct contact with sick, dead, or infected poultry, to consume meat and eggs only after they are thoroughly cooked, and to report dead birds to nearby veterinary authorities.'
The subclade currently circulating in Nepal remains a bit of a mystery. I've not seen any recent mention, but we know that both clade 2.3.4.4b (the primary global subclade) and a more regional 2.3.2.1a have been reported in Nepal.
This event was not unlike what we saw 3 years ago with the emergence of a new, more transmissible H5 Clade 2.3.2.1e virus in Cambodia & Vietnam that subsequently sparked an abrupt uptick in human infections between 2024-2026.A 3rd possibility exists, as eight months ago, in Viruses: Zoonotic Implications of the Co-Circulation of Clade 2.3.4.4b and 2.3.2.1a H5N1 Avian Influenza Viruses in Nepal in 2023, we looked at a report of a reassortment event which combined genetic elements from both subclades.
Zoonotic Implications of the Co-Circulation of Clade 2.3.4.4b and 2.3.2.1a H5N1 Avian Influenza Viruses in Nepal in 2023
Pragya Koirala 1, Manju Maharjan 2, Sharmila Chapagain 3, Barun K. Sharma 1,
Tirumala B. K. Settypalli 4, Charles E. Lamien 4 and William G. Dundon 4,*
Viruses 2025, 17(11), 1481; https://doi.org/10.3390/v17111481
Abstract
Samples collected from two avian influenza outbreaks in Bagmati Province in central Nepal between January and March 2023 were positive for H5N1. Full genomes were generated for both viruses, which revealed that one of the viruses was very similar to clade 2.3.4.4b H5N1 identified in Bangladesh in 2021/2022.
The second virus was a reassortant H5N1 virus consisting of four genes (HA, NA, NP, and M) originating from a clade 2.3.2.1a H5N1 and the remaining four genes (NS, PB1, PB2, and PA) originating from a 2.3.4.4b H5N1. Notably, this second virus had a high identity with 2.3.2.1a clade viruses identified in humans and cats in India in 2024–2025.
These are the first full genome sequences of H5N1 avian influenza viruses from Nepal and given the recent human infections by 2.3.2.1a H5N1 viruses in the region, these data will be of interest to both public health and veterinary authorities.
The caveat here is, this study analyzed only two poultry isolates - taken from two different farms roughly 10 km apart in early 2023 - which tells us very little about prevalence or spread of variants the region.
Regardless of the subclade involved, a large and escalating bird flu outbreak lying beneath the flyway between the two most populous countries (India & China) on the planet is very much worth our attention.
Stay tuned.
