Habitat destruction may be bringing migratory birds closer to communities, facilitating the spread of avian influenza.
Habitat Loss and Bird Flu Transmission
A new study suggests that habitat destruction, particularly in coastal areas of Malaysian Borneo, may be increasing the risk of bird flu (avian influenza) transmission from migratory birds to humans. Published in Nature Communications, the study examines how deforestation and other environmental changes bring migratory birds into closer proximity to human populations, thereby potentially facilitating the spread of the virus.
Study Findings and Antibody Evidence
Researchers analyzed blood samples from 2,000 people living near migratory shorebird habitats in northern Sabah, Borneo. Surprisingly, individuals—whether they owned poultry or not—had antibodies to the H5 strain of avian influenza, which is commonly found in wild birds. This suggests that human exposure to the virus may not be solely related to contact with poultry, as previously assumed. Notably, no human cases of H5 flu had been reported in these areas, but the presence of antibodies indicates past exposure.
Environmental Factors and Potential Risks
The study found that individuals with antibodies lived near coastal areas that serve as stopovers for migratory shorebirds, such as sandpipers and redshanks. These birds, which migrate along the East Asian-Australasian Flyway, are known to carry avian influenza. However, the study ruled out waterfowl like geese and swans as a primary source of transmission, as they were not found in the region.
Implications for Disease Surveillance
This study highlights the need for increased surveillance at migratory bird sites to better understand the risk of zoonotic diseases—diseases that can be transmitted from animals to humans. Researchers emphasize the importance of preserving wildlife habitats, as urban development and deforestation increase human-wildlife interaction, raising the risk of disease spillover.
Next Steps and Broader Concerns
The study’s findings challenge the conventional wisdom about avian influenza transmission, particularly the assumption that poultry is the primary risk factor. Experts, including Associate Professor Kimberly Fornace, suggest that understanding the links between habitat destruction, wildlife, and disease is crucial to mitigating future risks.
The study also raises concerns about the impact of urbanization on wildlife populations and the potential for future outbreaks, highlighting the need for further research into how environmental changes might alter disease transmission patterns.
