Merced County grapples with severe bird flu outbreak, leading state in cases and third nationally in infected poultry flocks. (Shutterstock)
- Merced County reports highest number of infected poultry flocks in California, with 5.7 million birds culled in 2024.
- Bird flu outbreak impacts Central Valley egg, poultry, and dairy producers, raising concerns for human health.
- Industry implements strict biosecurity measures, hoping for return to normal production by spring.
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As the bird flu outbreak continues to wreak havoc on Central Valley egg, poultry and dairy producers — not to mention grocery prices and concerns over human health — Merced sits in the epicenter of the crisis in California and across the country.
Marijke Rowland
The Merced FOCUS
Merced County in the central San Joaquin Valley reported the most infected flocks in the state in 2024, with 5.7 million culled birds. Since the start of the outbreak in 2022, Merced County has recorded the highest number of cases across California and the third-highest in the nation at 8.3 million birds, according to the U.S. Department of Agriculture.
The San Joaquin Valley is the state’s most prolific egg producer, and its counties have been heaviest hit by the crisis since the USDA began tracking the H5N1 avian flu in 2022. Following Merced in total number of poultry in infected flocks in California counties is Kern with 3.2 million, Stanislaus with 2.7 million, Tulare with 1.8 million, and Fresno with 1.7 million.
Nationwide, some 134 million birds have been affected by the virus since 2022 with cases recorded in all 50 states, including Alaska and Hawaii. The only two counties across the country with higher infected flock numbers than Merced were Sioux County, Iowa with 12.1 million birds, and Weld County, Colo. with 9.6 million birds.
In California, the avian flu has also spread to dairy farms, with 711 confirmed cases, according to the USDA.
“This has been the worst year, unfortunately,” said Bill Mattos, president of the California Poultry Federation. “It’s affected most of the nation very badly the last two years. And the Central Valley, from Sacramento to Bakersfield, is where we have most of the poultry and now dairy cows are getting it.”
Once the virus is detected, all poultry in the flock are quarantined and euthanized to prevent further spread. Infected dairy cows don’t need to be put down, but the illness significantly reduces milk production.
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Human Health Concerns and Economic Impact
The virus has also raised serious concerns for its potential to cross over and sicken people. Last year 66 confirmed cases of bird flu were reported in humans nationally — with more than half of those, or 37 cases, in California — the U.S. Centers for Disease Control stated. Most of those cases have been people who work in close contact with livestock at commercial poultry or dairy farms.
Last week, the first human bird flu death from this outbreak was reported in Louisiana. Merced County reported its first human case last October.
Outbreaks across the Valley and state have also driven up egg prices locally, with shoppers feeling shortages and higher costs. That includes cases reported in early December of last year in Merced County at a commercial egg producer that resulted in the deaths of 2.8 million hens.
“We are very aware of (the Merced outbreaks),” Merced County Agricultural Commissioner Sean Runyon said. “This is kind of a replay of what happened last year as well. Some of the same poultry flocks in Merced were affected last year and this year. We’ve been keeping up good communication with the CDFA to coordinate activities between public health and other agencies.”
The USDA and California Department of Food and Agriculture do not disclose the locations of facilities with outbreaks because of the potential for the virus to spread.
Merced County is the second-highest egg and poultry-producing county in the state, according to the most recent CDFA report from 2022, behind only San Joaquin County.
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Hope for Recovery and Future Outlook
Despite the scope and severity of the outbreaks in Merced and the state, Mattos said he is hopeful the industry can return to more regular production this year — perhaps as early as spring.
Avian flu, like the human flu, often spikes in winter. California egg and poultry producers, and now the dairy industry, have implemented strict biosecurity measures to mitigate the outbreak. This includes protective gear, disinfection stations, and restricting visitors.
“We are hoping to get birds back into the barns. We are hoping the price starts to see some reduction. That’s our goal to get things somewhat normal,” Mattos said. “Hopefully, by Easter, we can have the eggs back in the stores with prices that are less than they are now.”
About the Author
Marijke Rowland is the senior health equity reporter for the Central Valley Journalism Collaborative, a nonprofit newsroom that publishes The Merced FOCUS in collaboration with the California Health Care Foundation (CHCF).