The Centers for Disease Control and Prevention announced the second case of highly pathogenic avian influenza in a dairy worker in a week, and the third this year, but the agency said the risk to the public remains low.

As with the first case announced last week, the latest one involves a worker in Michigan.

“This case highlights the elevated risk of H5N1 infection, particularly for individuals who have contact, particularly unprotected contact, with animals,” CDC Principal Deputy Director Nirav Shah said on a call with reporters Thursday.

“In this instance, what we're really focused on are dairy cows, so no change in our overall risk assessment for the general public, but a renewed focus – a continued focus – on the risk that dairy workers may see.”

The announcement came the same day that USDA announced increased financial help for dairy producers. 

Ag Secretary Tom Vilsack has approved the transfer of $824 million from the Commodity Credit Corp. to the Animal and Plant Health Inspection Service for "critical rapid response activities," the department said.

"This funding allows APHIS to continue its critical work with state and local partners to quickly identify and address cases of HPAI/H5N1 in poultry and livestock, USDA said. It "will support anticipated diagnostics, field response activities, pre-movement testing requirements, other necessary surveillance and control activities, surveillance in wildlife for APHIS, the Agricultural Research Service’s (ARS) work in developing vaccines for HPAI in cattle, turkeys, pigs, and goats, and ARS and the Food Safety and Inspection Service’s food safety studies."

Natasha Bagdasarian, chief medical executive for Michigan’s Department of Health and Human Services, said in both the cases in the state, “Neither individual was wearing full personal protective equipment. This tells us that direct exposure to infected livestock poses a risk to humans, and that PPE is an important tool in preventing spread among individuals who work on dairy and poultry farms. We have not seen signs of sustained human-to-human transmission, and the current health risk to the general public remains low.”

The first person to contract H5N1 from cows was in Texas.  Another case in Colorado in 2022 involved exposure to infected poultry.

CDC said none of the three cases announced this year are associated with each other. 

CDC also said it “continues to closely monitor available data from influenza surveillance systems , particularly in affected states, and there has been no sign of unusual influenza activity in people, including no increase in emergency room visits for influenza and no increase in laboratory detection of human influenza cases.”

Shah said CDC has tested more than 40 people, and more than 350 have been enrolled in monitoring, including about 220 in Michigan’s monitoring system.

“None of this individual’s close contacts have developed or reported any symptoms,” Shah said.

Shah said use of PPE in states with affected herds has been “mixed.”

                Cut through the clutter! We deliver the news you need to stay informed about farm, food and rural issues. Sign up for a FREE month of Agri-Pulse here.

“Previously, we had focused on the importance of eye protection, given the conjunctivitis in the first two cases,” he said. “But this case also underscores the importance of barrier protection –  things like masks and other forms of protection for dairy workers, particularly those who are working with infected cows.”

He said CDC asked state health departments at the beginning May to start distributing PPE. “I've heard from state health officials in some states where there has been strong demand for things like goggles as well as other forms of PPE,” he said. “In other jurisdictions, it's been less so.”

USDA has made financial incentives available for affected farms that want PPE and released updated guidance on use of PPE on Wednesday.

Eric Deeble, USDA’s acting senior adviser for HPAI and deputy assistant secretary for congressional relations, said the department has “performed over 17,000 individual PCR tests for cattle,” but noted that does not mean 17,000 cows, “as many of these are pooled samples, so individual tests can represent many more animals.”

Deeble said he could not estimate how many cows in the country’s dairy herd of nearly 9.4 million are infected.

“It is uncertain how many cows in the national herd may have been affected,” he said, but USDA is trying to determine the extent of the infection through epidemiological investigations.

“I will say, fortunately, that H5N1 in dairy cattle is quite different than it is in poultry,” Deeble said. “Cows that get sick with this particular illness tend to recover well. There are no known mortalities due to H5N1, although a few animals were euthanized for testing purposes.” 

To date, USDA’s Animal and Plant Health Inspection Service has confirmed detections of H5N1 in 67 herds in nine states.

For more news, go to

This story has been updated to include information about USDA's use of the CCC.