Cooler Temperatures and the Congregation of Certain Species in the Same Winter Habitat May Increase the Spread of Avian Flu

Because of avian flu outbreaks on farms, finding a turkey this holiday season may be difficult.

Migratory wild birds may have spread the virus to commercial flocks, but no one has looked closely at this roving population until now.

Cooler temperatures and certain species congregating in the same winter habitat, according to researchers, may increase the circulation of H7 and H9 strains.

Temperature and nearby species could affect avian flu transmission in migrating birds

(Photo : FRED TANNEAU/AFP via Getty Images)

Avian flu is currently being monitored in the air at a number of poultry farms and live markets, where large outbreaks are expected, as per ScienceDaily.

However, migratory birds infected with H5, H7, or H9 strains have been linked to many of the deadliest outbreaks.

These wild birds live in dispersed populations where, even if infected individuals exist, virus levels in the ambient air are quite low, making them difficult to measure.

Pei-Shih Chen and colleagues previously discovered how to detect low levels of avian flu virus RNA in the environment.

Chen, Chen-Chih Chen, and a new team wanted to use this method to collect first-of-its-kind information on virus strains that really are likely to be making the rounds among migrating birds at a winter habitat and assess, which factors could be influencing the allowing it to move within the wild flock.

For two years, the researchers collected air samples near a large wetland in east Asia and filtered them through very fine membranes.

Viral RNA was extracted from the filters, amplified, and analyzed by quantitative real-time polymerase chain reaction for influenza strains A, H5, H7, and H9.

The results were then compared to weather data and the team's log of bird species present during the migratory season.

Lower daily temperatures were found to be associated with higher levels of influenza A, H7, and H9 in the air.

Furthermore, the presence of certain migratory bird species, including Anseriformes, Charadriiformes, and Pelecaniformes, was linked to periods of elevated H7 and H9 viral copies.

The researchers claimed that by demonstrating that ambient air sampling can detect airborne avian flu, they have identified potential factors that influence the strains of the disease that circulate in the winter among migratory birds.

Also Read 29,000 Turkeys Killed to Prevent a Highly Pathogenic Strain of Bird Flu in the U.S.

What role do wild birds play in avian influenza spread?

Waterfowls, in particular, are the natural host and reservoir of avian influenza viruses.

They can carry various avian influenza virus strains in their respiratory or intestinal tracts, as per the World Organization for Animal Health.

The virus can be harmless or fatal to wild birds depending on the virus strain and the species of bird.

When birds have few or no symptoms of the virus, they can spread it between neighboring countries or over long distances along their migratory routes.

During the off-season, wild birds play an important role in the evolution and maintenance of avian influenza viruses.

Waterfowls, gulls, and shorebirds are the main wild species involved in the viral cycle of avian influenza; however, the virus appears to pass easily between different bird species.

The virus is most likely transmitted through direct contact between farmed and wild birds.

As a result, it is critical to limit their exposure to wild birds in order to reduce the risk of avian influenza spreading to flocks.

Avian influenza has a high mortality rate and can have a significant impact on the health of both poultry and wild birds.

Wild birds, including endangered species, are also victims, despite being primarily regarded as disease vectors.

The effects of AI on wildlife could have a devastating impact on the biodiversity of our ecosystems.

Furthermore, avian influenza can infect mammals such as rats, mice, weasels, ferrets, pigs, cats, tigers, dogs, and horses by crossing the species barrier.

Related article: Bird Flu Outbreak Suspected as Dozens of Dead Birds Reported in Scotland, UK