Avian flu outbreak explained: CA declares state of emergency

• An outbreak of bird flu has ravaged the world’s birds since 2020 and infected cattle earlier this year.
• California Governor Gavin Newsom declared a state of emergency over the virus this week.
• Health officials also confirmed the first “severe” case and hospitalization for the H5N1 virus.

The burgeoning global bird flu outbreak continued its flight path across the country this week, with two major developments pointing to the virus’ growing concern about spreading.

California Governor Gavin Newsom declared a state of emergency over the virus on Wednesday, citing a worrying number of infected herds across the state in recent months and a need for more resources.

Since the state first identified the H5N1 avian influenza virus in cattle in late August, the California Department of Agriculture has confirmed 645 infected dairy herds.

Newsom’s announcement, meanwhile, came just hours after health officials confirmed the first serious case of bird flu in Louisiana, saying a person was hospitalized with an infection after being exposed to sick birds in his backyard.

In recent months, infectious disease experts have grown increasingly nervous about the possibility of a human pandemic linked to the virus, although the Centers for Disease Control and Prevention has maintained that the public health risk to humans is low.

Here’s where things stand.

Bird flu outbreak

The H5N1 virus first appeared in Europe in 2020 and has since become widespread in birds worldwide. The eruption has killed tens of thousands of birds and tens of thousands of sea lions and seals in recent years.

Birds carry the disease while migrating and can expose domestic poultry to the virus while never showing signs themselves, according to CDC.

The virus jumped to cattle herds for the first time ever earlier this year in a major escalation. Then, in October, a pig in Oregon tested positive for the virus, a particularly worrisome case since pigs can host both bird and human flu viruses.

There has not yet been any known human-to-human transmission. Still, the growing pattern of mammal-to-mammal transmission has infectious disease experts wary of the possibility that H5N1 could eventually become a human pandemic.

“If it continues to spread in animals, then eventually it will cause problems for humans, either because we don’t have food, because they have to start exterminating herds, or because it starts to make a jump in humans,” Dr. Jerome Adams, a former surgeon general and director of health equity at Purdue University, told Business Insider in April.

“The more it replicates, the more chances it has to mutate,” he added.

The ongoing multi-state dairy outbreak, believed to have started in Texas, has infected 865 herds in 16 states, according to the CDC, and has led to an increasing number of human cases among US dairy and poultry workers.

The CDC has so far confirmed 61 reported human cases and seven probable cases across the United States, although some scientists estimate the real number of infections to be higher.

More than half of the human cases are linked to interaction with sick cattle. The remaining infections have been traced to exposure to sick poultry or have an unknown origin, the CDC said.

state of emergency

California’s announcement Wednesday will give state and local authorities increased resources to study and contain the outbreak, Newsom said.

Related stories

“This proclamation is a targeted action to ensure that state agencies have the resources and flexibility they need to respond quickly to this outbreak,” the governor said in a statement.

Earlier this month, the Department of Agriculture said it would begin testing the nation’s milk supply for traces of the virus, requiring dairy farmers to provide samples of raw milk upon request. Until then, cattle testing for potential infections had been almost entirely voluntary.

Dr. Monica Gandhi, professor of medicine and associate chief of the division of HIV, infectious diseases and global medicine at the University of California, San Francisco, said the declaration is likely to give California a greater ability to monitor dairy farms for signs of the virus.

But declaring a state of emergency can be a double-edged sword.

Phrases “like ‘state of emergency,’ given that we have just been through a pandemic, can induce panic,” Gandhi said.

And it’s not time to panic yet, she said.

Gandhi praised the CDC’s “very measured” messaging around the virus so far and said health officials are closely monitoring the spread.