Bird flu cases have continued to climb in birds and cattle across California, prompting a greater sense of urgency for health professionals to prevent transmission of the virus to humans.
In the North State, the need for oversight has increased with the recent discovery of tens of thousands of bird flu infections in commercial game bird farms in the county, and a new variant detected separately at a commercial duck farm in Merced County.
Maurice Pitesky studies bird flu at UC Davis. He says bird flu has been around for decades. What makes the current H5N1 strain of the virus different from those in the past is its high mortality rate in animals and how easily it spreads.
“We're seeing it in species and in geographies we've never seen before,” Pitesky said. “We're seeing it in marine mammals. We're also seeing it now, as many people know, in dairy cows, and now, unfortunately, we're starting to see it in humans. So it's shown an amazing ability to be infectious to a variety of species.”
Along with this, Pitesky said, birds can recover from the virus or be asymptomatic like any other flu while still being infectious. This is especially dangerous for hunters and backyard farmers who may be exposed to bird flu without knowing.
Because of this, Pitesky said its crucial health providers test patients for bird flu if they are positive for influenza.
“We don't know the extent of an outbreak until we start testing,” he said.
A lack of clarity about testing for local health officials
A media blackout at national health institutions ordered by President Donald Trump’s new administration has made monitoring the spread of bird flu even harder.
North State Public Radio reached out to the California Department of Public Health, the Centers for Disease Control and Prevention (CDC), and the U.S. Department of Health and Human Services for information on what guidelines providers should be following when testing for bird flu. All three agencies told NSPR they would be unable to respond to any requests for information due to the indefinite pause in mass communications, or did not respond to information requests.
This is despite California’s declaration of a state of emergency just last month and the CDC’s health advisory declared this month requesting providers conduct more bird flu testing in patients. Both come as a new variant of the virus was recently detected in a commercial duck farm in Merced County.
“I've heard people who, in all honesty, should know better, say, ‘well, it's just in a handful of people at this point,’ or something to that equivalent. That's because we're not really robustly checking. We're not really looking for this virus in human populations in the same way that we're looking for it in animal populations.”Maurice Pitesky, veterinarian and epidemiologist at UC Davis
The CDC’s advisory told health providers to test hospitalized patients with cold and flu symptoms for influenza, especially those in an intensive care unit with severe symptoms. Should any test results be positive for Influenza A, the CDC recommended hospitals then test for the subtype of the virus to determine if a patient could have the H5 variant, indicating a potential bird flu infection.
In the North State, health providers only test patients for bird flu if they show clear symptoms of the virus, test positive first for influenza A and have a known exposure to the virus.
The Butte County Public Health Department said this is because California law says health agencies cannot force hospitals to report influenza cases. It’s up to individual hospitals to determine their own protocols for reporting.
Daniel Walker is the epidemiology and evaluation supervisor for Shasta County’s Health and Human Services Agency. He said it’s up to healthcare providers in the region to reach out to local health departments if they suspect a patient may have bird flu. How they determine this varies from hospital to hospital.
Cold and flu season complicates things
All of this comes amid a rough cold and flu season across the North State.
Dr. Tanya Layne is the ambulatory chairperson for Enloe Prompt Care in Chico and also owns a private practice.
Layne says this season, hospitals in the region are seeing between 7 to 12 admissions a day for severe cases of the flu.
“We’re seeing more complications, and our pediatric age group is getting hit pretty hard, not only with the flu but with RSV too,” Layne said. “We don’t screen for bird flu, we have what’s called a respiratory panel, and it covers about 20 viruses. Bird flu is not on it and we don’t routinely screen for it. Certainly we don’t at the prompt care.”
Pitesky said policies like those in the North State mean there will be cases of bird flu that go undetected.
“I've heard people who, in all honesty, should know better, say, ‘well, it's just in a handful of people at this point,’ or something to that equivalent,” Pitesky said. “That's because we're not really robustly checking. We're not really looking for this virus in human populations in the same way that we're looking for it in animal populations.”
He says human testing should be done on people who are not hospitalized and who may not be severely ill.
Pitesky said testing the entirety of a population, whether or not they have known exposures, can rule out the possibility of dangerous unknown infections.
