California reports 4 more probable H5 cases among dairy workers

The California Department of Public Health (CDPH) today reported four additional probable avian influenza infections among dairy workers and is awaiting final confirmation from the U.S. Centers for Disease Control and Prevention (CDC) on an earlier probable case identified during state testing .

The newly identified potential cases came from proactive testing over a three-day period, the CDPH said. All sick people had contact with infected cattle on nine different farms.

So far, all patients have had mild symptoms such as conjunctivitis. None of the people were hospitalized.

Delivery delays and late confirmation due to federal holidays

Shipping delays late last week and today’s federal holiday mean specimens are expected to arrive at the CDC early this week.

California reported its first outbreak in dairy cows in the Central Valley in late August, but the state – the country’s largest milk producer – quickly became the hardest hit. To date, the United States Department of Agriculture (USDA) has confirmed 100 H5N1 cases in dairy herds.

If the CDC confirms the five probable cases in California, the number of infections among dairy workers in the state would rise to 11. And if confirmed, the new cases would bring the year-to-date statewide total to 25.