H5n1 Bird Flu Spreads To Sea Otters And Sea Lions Along San Mateo Coast, Wildlife Experts Say

Researchers opportunity nan H5N1 vertebrate flu outbreak successful California elephant seals has dispersed to different marine mammals, including a oversea otter and oversea lion.

However, wildlife officials are cautiously optimistic nan outbreak will stay contained. It has truthful acold only been detected connected beaches successful San Mateo County, though testing is being conducted on nan coastline.

The strain of vertebrate flu recovered successful these animals contains a mutation that allows it to much easy transmit betwixt mammals. It is besides a different variety than nan ones recovered successful dairy cows and commercialized poultry. This 1 is Eurasian successful origin, and was first seen successful 2022. It has been detected successful birds that alert on nan Pacific Flyway, and is responsible for a wide mortality arena successful 2023 successful bluish fur seals connected an land successful eastbound Russia, said Christine Johnson, nan head of UC Davis’ Center for Pandemic Insights, during a property convention Thursday morning.

Johnson said researchers deliberation this is nan first discovery of nan A3 variety of nan microorganism connected nan Pacific Coast and truthful apt a caller preamble into North America, she said.

In precocious February, a squad of researchers from UC Davis, UC Santa Cruz, California Department of Fish and Wildlife and nan Marine Mammal Center announced they had recovered nan microorganism successful 7 dormant elephant seal pups collected from nan formation astatine Año Nuevo State Park. That number is now 16, but Johnson said apt much will beryllium confirmed successful nan weeks to come.

“This count reflects only nan animals that person gone done sampling and confirmatory testing successful aggregate labs,” she said. “We cognize location are much animals pinch signs of infection that we person sampled that are being tested crossed nan different laboratory systems.”

She said nary different otters person been found, but a “handful” of California oversea lions are “in nan queue.” This benignant of spillover, she said, is not unusual.

“Outbreaks impact a wide scope of birds and mammals, and these animals each stock nan adjacent statement ecosystem,” she said, though it’s “especially tragic erstwhile infections effect little communal type successful nan confederate oversea otter.”

Patrick Robinson, nan Año Nuevo reserve director, and a marine biologist astatine UC Santa Cruz, said 47 elephant seals connected nan mainland person died since nan commencement of nan outbreak, and nan wildlife squad is uncovering 2 caller symptomatic and 2 dormant animals each day.

Symptoms of vertebrate flu successful mammals tin see tremors, convulsions, seizures and musculus weakness.

He said it is normal for immoderate individuals to dice of earthy causes, truthful testing is critical. And he said nan percent of animals that person died successful nan Año Nuevo rookery is comparatively small: Only astir 5% of weaned pups and 6% of big males person died. Although, successful nan lawsuit of nan pups, that’s 4 times higher than past year’s decease rates. And he said, nan decease of ample males is “basically nonexistent successful astir males.”

He said 80% of nan big females had departed by nan clip nan outbreak began, and astir each of them are now gone. No big females died, and nary person been observed arsenic being symptomatic.

“The outbreak is not over, and we’re not really judge what’s going to hap successful nan future,” he said. “I stay hopeful astir this point correct now.”

In precocious 2022, nan H5N1 vertebrate flu microorganism decimated confederate elephant seal populations successful South America and respective sub-Antarctic Islands. At immoderate colonies successful Argentina, 97% of pups died, while connected South Georgia Island, researchers reported a 47% diminution successful breeding females betwixt 2022 and 2024. Researchers judge tens of thousands of animals died.

More than 30,000 oversea lions successful Peru and Chile died between 2022 and 2024. In Argentina, astir 1,300 oversea lions and fur seals perished.

At nan time, researchers were not judge why bluish Pacific populations were not infected, but suspected erstwhile aliases milder strains of nan microorganism conferred immoderate immunity.

The microorganism is amended known successful nan U.S. for sweeping done nan nation’s dairy herds, wherever it infected dozens of dairy workers, millions of cows and thousands of wild, feral and home mammals. It’s besides been recovered successful chaotic birds and killed millions of commercialized chickens, geese and ducks.

Two Americans person died from nan microorganism since 2024, and 71 person been infected. The immense mostly of infected group were dairy aliases commercialized poultry workers. One decease was that of a Louisiana man who had underlying conditions and was believed to person been exposed via backyard poultry aliases chaotic birds.