Diverse strains of highly pathogenic avian influenza (HPAI) H5N1 are lurking in New York City's bird population, according to a recent study that unveiled the presence of multiple viral genotypes in an urban environment.

The study, conducted from January 2022-November 2023, involved the collection of 1,927 samples from avian species in New York City parks, green spaces, and wildlife rehabilitation centers. The researchers found six samples from four bird species, including Canadian geese and a peregrine falcon, that tested positive for HPAI H5N1. Whole-genome sequencing revealed multiple genotypes, indicating a diverse viral population.

"It is important to state that all six positive samples came from either the Wild Bird Fund or the Animal Care Centers of New York City, stressing the important role that urban wildlife rehabilitation centers can play in urban viral surveillance efforts,” said researchers.

The study findings support the need for viral surveillance in urban areas that have green spaces and wetlands that support resident and migratory birds. Because of the closeness to dense human populations, it “creates an extensive urban animal–human interface”, where not only humans but cats and dogs can be affected, the researchers noted.

The researchers collaborated with local organizations and community scientists to implement culturally responsive science education and outreach, communicating the risks associated with HPAI H5N1. Their findings were disseminated through community boards and scientific conferences to ensure comprehensive public awareness. They also reported their findings to the United States Department of Agriculture (USDA) and discussed them with the New York City Department of Health and Mental Hygiene, as well as the Wild Bird Fund and the Animal Care Centers of New York City. Additionally, the researchers noted the importance of physicians in urban centers to be aware of the potential presence of HPAI H5N1 and be aware that atypical influenza cases in humans may be caused by avian influenza viruses.

"Our work highlights that the interface between animals and humans that may give rise to zoonotic infections or even pandemics is not limited to rural environments and commercial poultry operations but extends into the heart of our urban centers," they noted.

The study was funded by Flu Lab, anonymous donors, and the Richard Lounsbery Foundation.