Gov. Gavin Newsom declared a state of emergency Wednesday as the H5N1 avian flu virus spreads from the Central Valley to Southern California dairy farms, while federal officials confirmed the first severe case in the U.S. of a Louisiana patient hospitalized — —As the virus develops, there is concern that it will continue to spread across the country through migratory birds.
Newsom’s announcement will allow state and local agencies to take a more streamlined approach to responding to the virus and “provide flexibility in staffing, contracts and other rules to support California’s evolving response,” a statement said .
“Building on California’s largest testing and monitoring system in the nation, we are committed to further protecting public health, supporting our agricultural industry, and ensuring Californians have access to accurate, up-to-date information,” Newsom said in a statement. “While the risk to the public remains low, we will continue to take all necessary steps to prevent the spread of this virus.”
According to the U.S. Department of Agriculture, 645 California dairy herds have been infected with the H5N1 virus since August. Nationally, the number stands at 865 cases, dating back to March, when the virus was first identified in Texas cattle.
California has also seen multiple cases of infection in pet cats, including three announced on Wednesday.
According to the CDC, 61 people have been infected with the virus since March, the vast majority at dairies or commercial poultry farms. Most people suffer from mild illness, including conjunctivitis, pink eye, and upper respiratory tract irritation.
In California, 34 people have been infected with H5N1, all but one of whom contracted the virus through infected dairy products. The outlier is a child in Alameda County; the source of the infection has not been determined. There is also a suspected case in a child in Marin County who drank raw milk known to be infected with the virus. The CDC could not confirm whether the child was sick.
The Louisiana cases have concerned public health officials because of their severity. Federal officials would not provide details about the patient’s symptoms and deferred all inquiries to the Louisiana Department of Public Health.
Emails and phone calls to the agency went unanswered.
The patient reportedly had close contact with sick and dead birds in the patient’s backyard chicken flock, according to CDC officials. The virus is a version of H5N1 bird flu, which researchers have labeled D1.1, and is circulating among wild birds.
The strain circulating in dairy cows is known as B3.13.
This is the D1.1 version detected in a Canadian teenager who was hospitalized with serious illness in November. The source of the patient’s infection remains unclear.
Louisiana health officials and the CDC are investigating the patient’s contacts and conducting further genetic testing of the patient’s virus, said Demet Daskalkakis, director of the CDC’s National Center for Immunization and Respiratory Diseases. Analysis to determine what changes, if any, may have occurred.
“These additional laboratory investigations help us identify relevant changes in the virus, including changes that indicate an increased ability to infect humans, increased human-to-human transmission, or that currently available diagnostics, antiviral treatments, or vaccine candidates for the virus may be less effective,” Daskalakis said at a news conference Wednesday morning.
He said analyzes so far have not shown that the virus has changed in a way that makes it “better adapted to infection or transmission in humans.”
An analysis of the virus among Canadian teenagers shows mutations that make that version of the H5N1 virus more likely to infect humans. However, it is unclear whether these changes occur before infection (in the wild) or during the course of infection in children.
None of the children’s family members or contacts were infected, suggesting that the adolescents had changed during the course of their infection so that the virus hit a dead end when it couldn’t spread beyond the child.
These cases are similar to those historically recorded in Asia and the Middle East, where the H5N1 virus caused a mortality rate of approximately 50%. Since the virus was first discovered in 1997, 948 cases have been reported globally, resulting in 464 deaths.
To date, cases associated with the B3.13 strain circulating in dairy herds across the country have resulted in only mild symptoms.
Still, research shows that at least one viral isolate taken from a Texas dairy worker had a mutation that allowed airborne transmission between mammals and was 100% contagious to laboratory ferrets. fatal.
However, as is the case with Canadian teenagers, this version is believed to be unique to dairy workers and has not spread elsewhere.
Other studies have shown that version B3.13 only requires a single mutation to be efficiently passed from person to person.
Richard Webby, director of the World Health Organization’s Collaborating Center for Research on the Ecology of Animal and Avian Influenza, said the D1.1 version of the virus “concerns me a little bit.” “Not necessarily because I know it would evolve differently, but it does have a different combination of H5 and N1 that could theoretically help support a different set of mutations,” rather than the researchers’ experiments with version B3.13 Seen.
Daskalakis said the CDC continues to believe the risk to the general population is low, and the agency is working to expedite influenza and avian influenza testing at clinical and public health laboratories “to help expedite identification of this disease through routine influenza surveillance.” “like cases”.
Newsom’s office said, “California has established the largest testing and surveillance system in the country to respond to the outbreak.”