Public health officials are concerned about bird flu, which has so far been detected in three dairy farm workers — two in Michigan and one in Texas — as well as in cattle in a dozen states.
The farmworkers’ symptoms were mild, and researchers have not found that the H5N1 virus, also known as bird flu, can spread from person to person. The federal Centers for Disease Control and Prevention (CDC) says the risk to the general public is low. However, flu viruses evolve, and the H5N1 virus could mutate and gain the ability to infect people more easily.
“The reason public health authorities are and should be on high alert is that this is a potentially serious pathogen,” said Meghan Davis, an epidemiologist and microbiologist at Johns Hopkins University.
That is why state authorities are placing great emphasis on testing and monitoring dairy workers. But they are facing considerable difficulties.
According to the U.S. Department of Agriculture, the H5N1 virus is deadly to domestic poultry and can wipe out entire flocks in a matter of days. As a result, the poultry industry has responded aggressively to the threat, culling entire flocks as soon as it detects even a single infected bird. But H5N1 is less severe in cows, and dairy farms have responded less aggressively.
The CDC and USDA have advised dairy farms to monitor cattle and humans for the virus, but testing remains voluntary except for herds moving between states.
Additionally, dairy farms are often located in remote rural areas, and workers have little access to transportation and no sick leave. As a result, it is difficult for them to get to health care providers for testing and treatment. Many dairy workers, most of whom are immigrants, speak indigenous languages like Nahuatl or Quiché, according to the National Center for Farmworker Health, a nonprofit that provides support and training to centers that focus on farmworker health.
Amesh Adalja, an infectious disease physician and researcher at the Johns Hopkins Center for Health Security, stressed that the current strain of bird flu does not pose a pandemic threat to humans. That’s why, he said, now is the ideal time to put in place appropriate screening and surveillance measures.
“If you can’t get it right with something that’s as forgiving as this virus has been, in terms of its inefficiency in infecting humans, it really doesn’t bode well for when the stakes are higher,” Adalja said.
So far, cases of the virus have been reported among domestic cattle in Colorado, Idaho, Iowa, Kansas, Michigan, Minnesota, New Mexico, North Carolina, Ohio, South Dakota, Texas and Wyoming, according to the USDA. Last week, federal officials announced grants to farms to offset the cost of milk losses caused by sick cows. Four states — Kansas, Nebraska, New Mexico and Texas — are launching voluntary pilot programs to test for the virus in bulk milk tanks on dairy farms.
In Michigan, where the virus has been detected in 25 herds, Tim Boring, director of the state Department of Agriculture and Rural Development, said efforts are focused on helping farmers recoup their losses and agree to get tested. Last month, the agency announced it would use a combination of federal and state funds to give up to $28,000 to up to 20 affected farms.
The state has also launched a study to see if there are antibodies in people exposed to sick cows, with the goal of determining whether there were asymptomatic infections.
Natasha Bagdasarian, Michigan’s chief medical officer, said the state is working with community health clinics and local health departments to reach farmworkers.
“They not only know the farms in their counties, but they also know many farm worker organizations,” she said.
Dairy farm workers, who are often immigrants, can’t afford to miss a day of work and may be reluctant to ask for a test or say they feel sick, advocates say.
“This is a population that is vastly underserved in terms of outreach and trust that is built with federal and state agencies,” said Elizabeth Strater, director of strategic campaigns for the United Farm Workers union. “This is a group of workers that is among the poorest in the United States.”
Immigrants make up 51 percent of the daily workforce on dairy farms, and farms that employ immigrants produce 79 percent of the nation’s milk supply, according to the National Milk Producers Federation.
Amy Liebman of the Migrant Clinicians Network, a group of experts in migrant health education and outreach, said testing should be administered on farms rather than in clinics.
“Dairy farms are in rural areas, very geographically isolated. You can’t get all these workers in one place to do surveys or testing. You really have to try to go where the workers are,” she said.
But convincing farm owners to accept the offer hasn’t been easy. The Texas State Department of Health told Stateline that it had offered on-site testing to farmers, but as of mid-June, it had tested only about 20 symptomatic dairy workers who had volunteered for testing. It also donated personal protective equipment to “interested dairies” and posted an online notice offering to deliver the equipment.
Coordination between state and local agricultural and health departments is essential to tracking the spread of the virus. A lack of coordination and tracking can contribute to underreporting of cases.
“I think the virus is more widespread than what is currently being reported,” said Shira Doron, chief infection control officer at Tufts Medicine. “The barriers between agencies are really hampering our efforts right now.”
The CDC has offered a $75 stipend to any farmworker who agrees to get tested and provide blood and nasal swab samples to the agency. But Doris Garcia-Ruiz, who directs farmworker outreach at Texas Rio Grande Legal Aid, said that wouldn’t make up for days of lost income.
“If they take time off to go to their doctor, they don’t have sick leave and therefore won’t get paid,” she said.
The latest CDC figures show that at least 53 people have been tested in connection with the cattle outbreak, the majority of them in Michigan. Strater says that’s not enough.
“It’s appalling,” she said. “Our testing approach is very passive. They rely on workers showing up at health clinics; these are workers who are not going to seek treatment themselves unless they have a life-threatening condition.”
Getting workers to use personal protective equipment is also challenging. The CDC recommends that workers wear respirators, impervious aprons and coveralls, non-vented safety glasses or a face shield, and rubber boots with sealed seams that can be disinfected. It also advises workers to follow a specific sequence of steps for removing PPE at the end of a shift to avoid contamination.
“Dairy work is very wet and very hands-on,” said Christine Sauvé, who directs community engagement at the Michigan Immigrant Rights Center. “While some industries are very familiar with PPE, the full CDC recommendation is new and different. So it really needs to be promoted by the employer, but also by state agencies.”
Sauvé worries that Michigan is prioritizing farmers’ losses over the health of farmworkers in its response. While the risk to the public is low, she and other experts say the farmworker population should not be forgotten.
Bethany Alcauter of the National Center for Farmworker Health described the threat of bird flu as “a kind of ticking time bomb.”
“Maybe it’s not completely the case yet. But if we don’t manage it well, it could happen,” Alcauter said.