Harsh deportation measures have instilled fear among farmworkers who are crucial to the U.S.’s avian influenza control efforts, according to public health officials.

Most bird flu cases in the U.S. have been among dairy and poultry workers, making their cooperation vital for preventing and detecting new infections to stop a potential pandemic. However, public health experts are finding it increasingly difficult to engage with these workers as many are afraid to interact with outsiders or even leave their homes.

“People are extremely fearful of stepping outside, even for basic necessities like groceries,” explained Rosa Yanez, a community outreach worker with Strangers No Longer, a Catholic organization in Detroit that assists immigrants and refugees in Michigan with legal and health issues, including bird flu. “There’s a genuine concern about family separation — parents are scared of being separated from their children,” she added.

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“Initially, people were eager to learn about the bird flu,” Yanez continued. “Now, they’re primarily focused on understanding their rights.”

Outreach staff who educate farmworkers about bird flu, distribute protective equipment, and facilitate testing have observed a notable change. This shift began in California, where the bird flu has hit hardest, following immigration raids that started on January 7, the day after Congress confirmed President Donald Trump’s election victory. During these raids, Border Patrol agents indiscriminately detained about 200 Latino farmworkers and day laborers in California’s Central Valley, sparking a lawsuit led by the American Civil Liberties Union on behalf of the United Farm Workers union and others detained.

Described as a “fishing expedition,” the three-day “Operation Return to Sender” raid “shattered families and terrorized the community,” according to the lawsuit.

Yolanda Aguilera Martinez, a legally residing grandmother and farmworker with no criminal record, was one of those stopped. She was forcibly removed from her car and handcuffed by plainclothes agents, despite following traffic laws on her way to a medical appointment, the lawsuit details. While Aguilera Martinez was eventually released, others were not so fortunate; they were held in harsh conditions before being deported without explanation or legal counsel, the lawsuit claims.

The news of the raid spread quickly throughout California, home to an estimated 880,000 predominantly Latino farmworkers. This group is vital as dairy farms employing immigrant labor produce nearly 80% of the U.S. milk supply, a 2014 survey showed.

“Post-Operation Return to Sender, dairy workers have been even more reluctant to discuss their lack of protective measures and sick leave benefits, even anonymously,” stated Antonio De Loera-Brust, a representative for the United Farm Workers.

Similar chilling effects from raids and immigration policies enacted after Trump took office have been reported by outreach workers in other states. Trump’s harsh rhetoric and promises of mass deportations during his campaign set the tone. “They’re not humans, they’re animals,” he remarked about undocumented immigrants last April.

Trump’s initial legislative act was the signing of the Laken Riley Act, which mandates federal detention for immigrants charged with any crime, regardless of conviction. On January 20, the Department of Homeland Security lifted the “protected areas” policy, allowing arrests at schools, churches, and hospitals. Recently, the administration deported over 100 Venezuelans and others without a hearing, ignoring a court order to halt the deportation flights to El Salvador.

The implications for public health are significant: Infectious disease experts emphasize the importance of preventing and detecting bird flu among farmworkers to avoid a pandemic. This has led to government-funded efforts to monitor and protect these workers for signs of the virus, like red eyes or flu symptoms.

“Every sick worker represents a risk, so protecting them benefits everyone,” De Loera-Brust commented. “The virus doesn’t discriminate based on your immigration status.”

Potential for a Pandemic

Since March 2024, approximately 65 dairy and poultry workers have tested positive for the bird flu, but real infection rates are likely higher. A KFF Health News investigation revealed that less comprehensive surveillance led to undetected cases on farms last year, and studies indicate previous infections in untested farmworkers.

Efforts to improve bird flu testing by state and local health departments were making headway until recently, noted Salvador Sandoval, a recently retired doctor from the Merced County health department in California. “Now, seeing a mobile testing unit makes people think of Border Patrol,” he said.

Last year, outreach organizations engaged with farmworkers at community events like food distributions, but these are no longer well-attended, Sandoval and others reported.

“Regardless of legal status, anyone who looks like an immigrant is experiencing heightened fear,” Hunter Knapp, development director at Project Protect Food Systems Workers in Colorado, observed. He noted that some Latino community health workers have reduced their outreach efforts due to concerns about potential harassment by authorities or the public.

A Latina outreach worker in Michigan, who requested anonymity due to fears of retaliation against her family, shared, “Many are avoiding doctors because of the immigration climate.”

“They’d rather stay home and hope that the pain or eye redness subsides,” she explained. “The situation has intensified this year, and the level of fear is extremely high.”

Since Trump’s inauguration, the Centers for Disease Control and Prevention has reported significantly fewer human bird flu cases. In the three months before January 20, the agency confirmed two dozen cases. Since then, only three cases have been detected, including two severe enough to require hospitalization.

While the CDC maintains its surveillance of the bird flu, Jennifer Nuzzo, director of the Pandemic Center at Brown University, expressed concerns that the reduction in cases might be due to a decrease in testing rather than a true contraction of the virus’s spread. “I’m worried we’re seeing a reduction in surveillance rather than a reduction in the virus spreading,” she said.

Undetected infections pose risks not only to farmworkers but also to the broader public. Viruses mutate within hosts, and each infection represents a chance for the virus to evolve. A recent case in Louisiana highlighted this risk: A person who died of the bird flu in December had viruses that had evolved to potentially enhance human-to-human transmission, though, fortunately, no further spread occurred due to the patient’s isolation in a hospital.

However, this might not be the case if infected farmworkers don’t receive medical treatment and reside in crowded living conditions or detention centers, where the virus could spread, noted Angela Rasmussen, a virologist at the University of Saskatchewan in Canada. Although the bird flu doesn’t easily transmit between humans like the seasonal flu, it could potentially evolve to do so more effectively in close quarters.

“My concern is that we might not realize this is happening until some people become severely ill,” Rasmussen stated. “By then, the outbreak could spiral out of control.”

While the virus may never evolve to spread easily between people, the possibility exists. Rasmussen described such a scenario as “catastrophic.” According to a new report by her and her colleagues, an H5N1 bird flu pandemic could overwhelm healthcare systems and “cause millions more deaths” than the COVID-19 pandemic.

Decline in Vaccinations

In late 2020, the CDC launched a flu vaccine campaign aimed at over 200,000 livestock workers, hoping to reduce the risk of co-infection with seasonal and bird flu viruses. Such co-infections could allow the viruses to exchange genetic material, potentially creating a bird flu strain as transmissible as the seasonal flu.

However, Sandoval noted that vaccine uptake plummeted immediately following the January operation in California.

U.S. Customs and Border Protection officials stated they arrested 78 “unlawfully present” immigrants during the three-day operation, including a convicted sex offender and others with criminal records for vandalism and petty theft. The agency did not specify the charges against each individual or confirm if all had been prosecuted.

Former officials from the Biden administration, which was ending as the arrests took place, distanced themselves from the operation in interviews with the Los Angeles Times.

Mayra Joachin, an attorney at the ACLU of Southern California, characterized the operation as uncharacteristic of the Biden administration, noting it involved indiscriminate arrests by Border Patrol in the country’s interior. “It aligns with the Trump administration’s broader strategy of instilling fear in immigrant communities,” she said, “as evidenced during the election campaign and subsequent actions targeting anyone perceived as a noncitizen.”

In March, an assistant chief in the Border Patrol unit responsible for the operation, David Kim, described the operation as a “proof of concept.”

“We now know we can extend our reach as far as distance is concerned,” he told the Southern California news outlet Inewsource.

The Department of Homeland Security did not respond to requests for comment. In an email, White House spokesperson Kush Desai wrote, “Contrary to what the ‘experts’ believe, combating the Avian flu epidemic and enforcing our immigration laws are not mutually exclusive.”

Anna Hill Galendez, a managing attorney at the Michigan Immigrant Rights Center involved in bird flu outreach, reported that unusually aggressive tactics by Immigration and Customs Enforcement agents in late January deterred sick dairy workers in Michigan’s Upper Peninsula from seeking medical care. They reached out to the center for assistance.

“They needed medical care, flu vaccines, personal protective equipment, and testing,” Hill Galendez said. “But they were too frightened to venture out due to immigration enforcement.”

Lynn Sutfin, a public information officer at the Michigan Department of Health and Human Services, responded to inquiries about the situation in the peninsula in an email to KFF Health News, stating, “The farmworkers did not take the local health department and MDHHS up on the testing offer.”

The CDC declined to comment on the impact of immigration actions on farmworker outreach.

Adapting to the new reality, Yanez now emphasizes her bird flu advice in Michigan by coupling it with information on immigrant rights. Knapp, in Colorado, mentioned his organization is shifting its approach away from bird flu outreach at gatherings where farmworkers typically meet, as these could be perceived as setups — and potentially become targets for ICE raids.

Outreach workers who live among farmworkers are also becoming more cautious. “As Latinos, we are always identified,” said the outreach worker who wished to remain anonymous. “I have a visa that protects me, but things are rapidly changing under the Trump administration, and frankly, nothing is certain.”

KFF Health News, formerly known as Kaiser Health News (KHN), is a national newsroom that produces in-depth journalism about health issues and is one of the core operating programs at KFF — the independent source for health policy research, polling, and journalism.