Concern Over Bird Flu Spread In House Mice, Domestic Cats

NEW DELHI, (IANS) – The H5N1 virus, or bird flu virus, has raised fresh concerns for humans with reports of spillover to mammals like domestic cats and mice, infectious disease experts said on June 12.

The World Health Organization on June 11 confirmed a human infection with bird flu caused by the H9N2 virus in a four-year-old child in West Bengal.

It is the second human infection of H9N2 bird flu from India, with the first in 2019, the agency said.

The US Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service on June 12, reported 36 more H5N1 avian flu detections in house mice and four more virus detections in domestic cats — from New Mexico county.

While there is no immediate threat, biologist Vinod Scaria, in a post on X.com, said it “is concerning as the virus is moving to domestic animals with human contact”.

The bird flu virus H5N1 has seen a significant increase in spillover to mammals in recent years. The virus killed a record number of birds in 2023.

It spread to otters, sea lions, minks, foxes, dolphins, and seals, among others.

The virus also killed 29 cats in Poland and 38 of 40 shelter cats in South Korea. Meanwhile, in separate incidents, the bird flu virus also affected several humans in China, Chile, the US, and India.

The virus in the child was detected by health authorities in Australia’s Victoria.

In late March, H5N1 infected dairy cows in the US, and subsequently, at least three humans in Texas and Michigan have reportedly contracted the virus from sick cattle. More recently, a 59-year-old man in Mexico died after being infected with H5N2 bird flu, a strain not previously seen in humans.

Avian influenza in humans can range in severity from mild, resembling a common head cold, to life-threatening. Beyond respiratory problems, symptoms of bird flu can include eye inflammation (conjunctivitis), stomach and intestinal issues (gastrointestinal symptoms), and even brain inflammation (encephalitis) and brain dysfunction (encephalopathy).

In some special cases, some people exposed to bird flu, particularly the H5N1 strain, show no symptoms at all.