By: Timothy Wanninger
Influenza viruses are well-recognized viruses which cause respiratory disease and have a history of causing various historical epidemics and pandemics. These viruses are not only transmitted from person to person,
but can also transmit from animal reservoirs, such as wild avian species, to humans resulting in zoonotic transmission events. Laura Borkenhagen, a PhD student in the lab of Dr. Jon Runstadler, DVM, PhD at Tufts University, and a UTMB One Health collaborator, studies zoonotic pathogens. She notes that Southeast Asia is a key region for influenza
virus surveillance due to the large poultry industries present and the differing agriculture practices, including open air farming and wet markets, which facilitate interactions between wild birds, domestic birds, and people.
Laura and collaborators from multiple institutions recently authored a new paper, published in the journal Influenza and Other Respiratory
Viruses, regarding a potentially novel introduction of avian influenza A virus strains into Myanmar live bird markets. The viruses were detected when conducting One Health surveillance in live bird markets in Myanmar. In this study, samples were collected
from poultry, bird market workers, and the environment, across three live bird markets in Yangon, Myanmar in the fall of 2019. Among 297 samples tested, three influenza A viruses were isolated, all were subtyped as A/H9N2. These isolates represent
potentially novel introductions of H9N2 into Myanmar as the hemagglutinin and neuraminidase sequences were most closely aligned with viruses from outside of Myanmar. In addition, the H9N2 isolates from this study contained sequence elements that could
facilitate human infection, for example isolates clustered near the G9/Y280 lineage many of which have been frequently identified among humans. Isolates also had a L226/234 amino acid (H3/H9 numbering) in the hemagglutinin protein which has been associated
with increased α2,6‐linked sialic acid‐terminated receptor affinity important for human transmission and a A588V mutation in PB2 which has shown improved polymerase function in mammalian cells. A One Health approach was essential for the completion
of this study, with a team of human and veterinary health professionals across two Myanmar government agencies conducting the sampling and sample processing across both human and animal subjects.
While a researcher at Duke University under Professor Gregory Gray (now at UTMB), Laura conducted the field sampling and laboratory training of human and veterinary health professionals in Myanmar. Laura noted that involving people who understand the
local dynamics, as well as those with veterinary/agricultural expertise, ensures that the nuances of these settings are taken into account. Moreover, she explained that sampling poultry as well as people for influenza viruses ensures that the broader
picture is being uncovered, as opposed to sampling only one host. Tim Wanninger contributed to the manuscript development of this work.
Building off of the results from this study, Laura and the other authors of the paper recommend continued sampling of live bird markets in Myanmar, which would help identify novel and reassortant influenza viruses, and potential zoonotic events. Laura
also explained that regular sampling would provide useful data to poultry farmers in Myanmar to help them manage the health of their flocks. Thus, the increased surveillance recommended offers the opportunity to better protect both human and animal
health in the region.