​Tulare County's H5N1 Respo​nse – A Model for California​

Originally published: October 2025

When H5N1 (bird flu) started spreading across the U.S. in 2024, Tulare County Public Health knew it could face significant challenges due to the vast dairy agriculture industry in the region. “H5N1 is a virus that primarily affects birds, but can also infect dairy cattle, and humans, typically through direct contact with infected animals." said Nilsa Gonzalez, Tulare County Public Health Deputy Director, Environmental Division. 

Tulare County Public Health leaned on California Department of Public Health (CDPH) Future of Public Health (FoPH) and other federal funding sources to advance their public health infrastructure to prepare for emergency incidents just like this.   

“Tulare County has oversight of the Tulare and King Counties Milk Inspection Programs," Gonzalez said. “We knew early on once we started to hear about H5N1 impacting other states that if and when it arrives in California, it is going to land in Tulare County, and we were prepared."

The County itself is the top milk producer in California and the second largest in the nation. If the virus were to reach California, it would threaten Tulare's local economy, thousands of farm workers, and neighboring communities.

“Thanks to FoPH and California Strengthening Public Health Initiative (CASPHI) funding, as well as Centers for Disease Control and Prevention (CDC) Epidemiology and Laboratory Capacity Program funds, we had systems in place to help mitigate the spread ofthe virus to humans," Gonzalez explained. ​ 

​Building Preparedness Before the Outbreak  

Months before H5N1 reached California, Tulare County Health and Human Services Agency gathered more than 80 partners, farmers, hospitals, industry and local, state and federal agencies to walk through different H5N1 outbreak scenarios.

“It was about sitting at the table, working through real scenarios that built the connections and trust that carried us through when the virus actually arrived," said Gonzalez. “Once that first case hit our county, we had clear lines of communication in place, and we knew what we needed to do."

While the United States Department of Agriculture (USDA) and the California Department of Food and Agriculture (CDFA) managed the spread of H5N1 among poultry and dairy cattle, the CDC, CDPH and Tulare County Public Health led prevention efforts to mitigate the spread of H5N1 to humans.

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“We were prepared. By leveraging FoPH funds we successfully added the positions of a public health lab director, deputy health officer, quality infection prevention nurse, nursing supervisor, equity coordinator and multiple epidemiologists and emergency preparedness staff. Every one of them played some part in our H5N1 response and without that added layer, it would have been much more difficult." 

— Tulare County Public Health Director, Karen Elliott  ​

Arrival of H5N1 – Protecting Workers and Families  ​​

On August 30, 2024, Tulare County confirmed its first infected dairy herd and just weeks later, on October 3rd, the county saw its first human case. Tulare's public health laboratory – funded in part by FoPH – was one of the first in California authorized to test for H5N1. Over the course of the outbreak the lab processed 1900 samples from hospitals and clinics from around the region confirming 22 human cases, with 18 of them local. 

“Nurses checked in with nearly 2,000 exposed workers, making sure they had access to testing, follow-up care and medication to help prevent illness," said Gonzalez. “They also created information packets for dairy employees that were utilized by other counties. We weren't just responding, we were leading." The support from FoPH and CASPHI funding enabled Tulare County to partner with 14 federally qualified health centers (FQHCs) to make testing and treatment available across the county's large rural geography. Outreach materials were delivered in multiple languages to ensure access for all workers.

“We relied on trusted messengers—our clinics and community health partners, to help spread the word," said Staci Chastain, Tulare County Public Health Deputy Director of Health Operations. “Building on the strong partnerships we formed during COVID, we were able to extend our outreach even further. That's how we reach people who might not otherwise connect with government."

With farm workers at the heart of Tulare's strategy, their emergency preparedness program worked with the agricultural commissioner, creamery representatives, and the Tulare County Farm Bureau to deliver 1.8 million pieces of PPE directly to dairies. PPE included safety goggles, face shields, respirators, nitrile powder-free gloves, and bouffant caps.“We took the importance of distributing PPE to the dairies very seriously. Through our scheduled Point of Distribution events we were able to provide equipment to all of the Tulare County dairies. PPE meant workers were protected and farms could keep operating safely," said Elliott.  ​​

A Blueprint for the State  ​

By the end of 2024, Tulare County had managed nearly half of California's H5N1 human cases. Its coordinated response became a model and resource for other partners. Residents and health departments of neighboring counties leaned on the Tulare County Public Health Laboratory for testing. 

“Kern and Fresno County residents utilized the lab for testing, the lab had a notification process in place for results to their public health departments which was critical with their follow up and contact tracing as applicable," Gonzalez explained. “Kings County Public Health Department also relied on Tulare's laboratory for expedited Avian Flu PCR testing"

Tulare County's communication materials for dairies and workers were also adopted statewide.  “The way we responded, reached out, and created communication for the dairies and workers truly provided a blueprint for other counties in California," Elliott said.   

Though the outbreak has slowed, monitoring still continues. Some farms remain under quarantine and case management work hasn't fully stopped. According to the CDFA there have been several dairies that have shown the presence of the virus in recent months and all dairies in the state continue to be under regular surveillance. The last human case reported in California was on January 14, 2025.  

Tulare County's experience shows that when local health departments have the staff and resources they need, they can protect people, keep industries running and build trust in the community – even during an outbreak. FoPH funding is doing exactly what it is intended to do - build core infrastructure to help locals respond to emergent needs and priorities.  

“FoPH funding has significantly bolstered Tulare County Public Health's capacity," said Elliott. "This support would have been invaluable during the COVID-19 pandemic, as it has enabled us to respond more swiftly to outbreaks, prevent infections, and enhance disease tracking. In this instance, investing in public health has protected employees, contained outbreaks, and reassured communities – and that's the true impact of this funding." ​​​​

Photos courtesy of: Tulare County Public Health

​If you’re a member of the media and have a question about this story, email Media@cdph.ca.gov​. ​​​​​​​​​​