California has reported its fourth bird flu case, with the outbreak linked to the dairy industry in the state, according to officials on Thursday.

Similar to previous cases, the infected individual is employed in the agricultural Central Valley and had contact with sick dairy cows, the California Department of Public Health stated in a news release. All individuals confirmed with the virus in California have experienced mild symptoms, such as reddening or discharge from the eyes, and none have required hospitalization.

The confirmed cases do not show any connections, indicating that the virus is likely spreading widely among dairy herds, making those working with the animals at greater risk.

In total, 17 cases of bird flu have been reported across the U.S. this year, with almost all involving individuals working with infected poultry or dairy livestock.

Additionally, there are two more individuals in California’s Central Valley who are suspected of having avian influenza, with test results pending from the U.S. Centers for Disease Control and Prevention in Atlanta.

While California officials assert that the general public’s risk remains low, they caution that people who work directly with infected animals have a higher risk of contracting bird flu.

On Thursday morning, CDC officials indicated that the first two cases in California were caused by the same viral strain found in affected dairy cows. There appears to be no significant genetic changes in the virus that would enhance its ability to infect people or undermine the effectiveness of antiviral treatments.

As of Thursday, nearly 100 dairy farms in central California have confirmed cases of bird flu in cattle, local officials reported. Health authorities are advising farm workers to wear personal protective equipment, including N95 masks, goggles, face shields, and gloves.