WHO chief raises alarm about bird flu circulating among US livestock

MONDAY, April 22, 2024 (HealthDay News) — The H5N1 avian influenza virus affecting livestock in the U.S. is increasingly appearing in mammals, a dangerous sign that it could one day easily infect humans.

This warning was made late last week by Dr. Jeremy Farrar, chief scientist at the World Health Organization, CNN reports.

“We must monitor, more than monitoring, we must ensure that if H5N1 reaches people through person-to-person transmission, we are able to respond immediately by ensuring equitable access to vaccines, therapeutics and diagnostics,” he said at the conference conference, press conference on the new WHO definition of airborne pathogens.

In rare cases, H5N1 can infect a person who has regularly been in close contact with infected animals, as happened on a Texas ranch earlier this month, but so far human-to-human transmission of the virus has been very difficult.

However, the virus is increasingly appearing in mammals, which are much closer relatives of humans than birds.

“The big concern, of course, is that by doing this and infecting ducks and chickens and now more and more mammals, this virus will evolve and develop the ability to infect humans,” Farrar said. “And then, more importantly, the ability to move from person-to-person transmission.”

According to the WHO, the number of deaths that would have occurred would have been catastrophic: since 2003, there have only been 889 cases of human infection with avian influenza reported worldwide, but in 463 (52%) of these cases the infected person died.

“This virus is a truly scary virus. I wouldn’t want to see it in people,” Dr. Richard Webby, who heads the WHO’s coordinating center for environmental research on influenza, told CNN.

Webby is also a scientist at St. Jude Children’s Research Hospital. He has studied H5N1 for two decades and said the transition to mammals is ominous.

“What’s happening now is that many more small mammals are infected with this virus, and we’ve seen that over the last 20, almost 25 years of monitoring, so it’s absolutely concerning,” he said.

Currently, H5N1 does not appear to have the acquired mutations that allow human-to-human transmission of the virus, so “this virus has a big hurdle to overcome to become a true type of human pathogen,” Webby said.

The virus linked to a single human case reported this month in Texas was studied by the US Centers for Disease Control and Prevention (CDC), which said it appeared vulnerable to existing antiviral drugs.

The man involved showed only mild symptoms but was placed in isolation. At the time, the CDC rated the threat to the public as “low.”

The current H5N1 outbreak in US cattle herds has occurred in eight states: Texas, New Mexico, Kansas, South Dakota, Idaho, Michigan, Ohio and North Carolina.

The Centers for Disease Control and Prevention (CDC) said it has also created an H5N1 vaccine candidate virus. The strain will be ready to help produce a viable vaccine if the need arises.

More information

The US Centers for Disease Control and Prevention (CDC) has more information on avian influenza.

SOURCE: CNN