Bird flu has been found in dairy cows in 16 states and in more than 60 humans on the mainland so far this year.

Hawaiʻi is on high alert after an increasing number of avian influenza cases in California's dairy industry and a severe infection in a human prompted Gov. Gavin Newsom to declare a state emergency Wednesday.

Local officials have deemed the bird flu virus a low risk, but in a state uniquely vulnerable to contagions of all kinds from the mainland, they remain worried about the state's milk supply and human health issues.

H5N1 Avian Influenza -- commonly known as bird flu -- can be deadly for humans and birds. Nationally, there have been 61 human cases since April. The U.S. Centers for Disease Control and Prevention reported its first "severe" case on Wednesday in Louisiana.

Cattle can also contract the virus, which they can pass on through raw dairy products. This contributed to Newsom declaring an emergency as 645 of the state's more than 1,100 dairies have had confirmed cases in their herds. Thirty-four human cases of bird flu have been detected in California.

Bird flu was detected for the first time in Hawaiʻi in November during a routine sampling of Oʻahu's wastewater system. It was later detected in wild birds and in a duck sanctuary in Wahiawā and again on Dec. 2 in Hilo's wastewater on the Big Island.

Hawaiʻi authorities have continued to track the state's incidents of bird flu but there have not been any confirmed cases since Dec. 2. On Friday, the state implemented a 90-day pause on the movement of domestic and poultry birds in a bid to mitigate the potential spread of the virus among Hawaiʻi's wild and domestic bird populations.

California produces 20% of the nation's milk and supplies the lion's share of milk to Meadow Gold in Hawaiʻi, one of the state's largest dairy distributors and the owner of the state's only commercial dairy farms.

The milk is pasteurized before it leaves the mainland and again on arrival in Hawai'i. That process of heating the milk to remove pathogens, combined with testing in California, makes the presence of the virus extremely low.

Arizona -- without any confirmed bird flu cases in cows -- is also a major supplier of milk to Hawaiʻi through other brands, Hawaiʻi Food Retail Industry Association President Lauren Zirbel said.

For Cloverleaf Dairy, which has 400 milking cows on the Big Island's northern coast, "there's always a concern" about bird flu or other pathogens, Meadow Gold owner Bahman Sadeghi said.

But the risk so far appears to be minimal because the strain of bird flu in Hawaiʻi is different than the one on the mainland, Sadeghi said.

The major concern is raw milk products, Sadeghi says, which are illegal in Hawai'i despite almost 10 years of efforts to legalize raw milk sales.

Sadeghi has nevertheless volunteered his Hilo pasteurization silo and North Kohala farm for testing by the state Department of Health.

"We're awaiting further instructions," he said.

The U.S. Department of Agriculture is currently testing milk across select states, including California, but not in Hawaiʻi.

Any trickle-down effects from the mainland dairy industry's woes are hard to predict for Sadeghi, who says the commodity's price is dictated by myriad factors, including the price for butter, cheese and whey, among other things.

The state's current focus is on wild and domestic birds, with the departments of Agriculture, Land and Natural Resources and Health coordinating efforts.

"The virus has been around for many years in some version," Hawaiʻi Health Director Dr. Kenneth Fink said at a news briefing Friday with Green and state veterinarian Isaac Maeda. "It does not seem to have variants or mutations like we saw with Covid. It seems more stable, which is reassuring."

Fink said despite the low risk of transmission to humans, the health department is cautioning livestock workers and residents to be careful around wild and domestic birds.

State Agriculture Director Sharon Hurd says the voluntary 90-day stop-movement order for poultry and domestic birds was put in place to help stem the spread, though if the situation worsens a mandatory order may be imposed.

Hawaiʻi's egg industry is one of the state's most valuable sectors of agriculture. Local producers have said they are working to safeguard themselves and their flocks from the virus. The risk to other wild and native species remains a serious concern.

Hurd says that means people need to stop feeding feral chickens and other wild birds because it just takes one infected bird to get too close to the others to potentially spread the disease.

The departments are all working to plan for the worst-case scenario but are trying to keep from making premature decisions, Hurd said.

"Right now we're deciding what to do next," Hurd said Wednesday. "We're trying to make a science-based, data-driven decision."