The agriculture and food industry is entering an era of stepped-up precautions against the spread of the H5N1 bird flu virus now that it has appeared in cattle for the first time, said FDA commissioner Robert Califf at a Senate hearing on Wednesday. “Unfortunately, there is no absolute barrier that can be created,” he said.
Farmworkers will more commonly wear protective gear and the government will limit the movement of infected herds. The FDA will continue to monitor the milk supply to assure it is free of the virus, said Califf. The agency also is preparing for the possibility of the disease spreading to humans.
“The public need not be worried. The risk is still low that [it] will happen,” said Califf during a Senate Appropriations subcommittee hearing on the FDA budget for fiscal 2025. “We have to prepare for the possibility it might jump to humans,” which means identifying tests, antiviral medicines, and vaccines that would be needed.
There is one known case of cattle-to-human transmission of highly pathogenic avian influenza (HPAI) — a dairy worker in Texas, reported on April 1. The worker was treated for mild symptoms of conjunctivitis and recovered.
“How do you create a very good barrier so people are comfortable you’ve got this thing contained or stopped from further migration?” asked Sen. John Hoeven, a North Dakota Republican. Hoeven was concerned that the virus, by moving through cattle and perhaps hogs, would become contagious to humans. “It’s gone from cattle to humans already in some cases, correct?”
“We have to be ready. And we have to do everything we can to limit the spread of the virus, which has gone around the world multiple times now in many difference species,” said Califf. Containment would reduce the chance of the virus becoming more transmissible.
The USDA has encouraged livestock producers to adopt strong biosecurity measures, such as limiting access to their facilities, washing off boots and donning protective clothing before entering a barn, and not sharing equipment with other farms. The CDC recommends that livestock workers, veterinarians, animal health personnel, and slaughterhouse workers wear “appropriate personal protective equipment,” such as fluid-resistant coveralls, face shields, boots, and gloves in buildings with sick or dead birds and animals.
To date, bird flu has been found in 36 herds in nine states, from Idaho to North Carolina, including 12 herds in Texas. Califf said the FDA began testing milk nationwide “knowing it was likely there were more infected herds than we initially knew, and that’s what we found.”
Nearly 91 million birds in domestic U.S. flocks have died of HPAI or have been culled in infected flocks since outbreaks began in February 2022. Most of the birds were egg-laying hens or turkeys being raised for meat.
Viruses constantly evolve, said Califf. “The real worry is it will jump to the human lungs, where, when this has happened in other parts of the world for brief outbreaks, the mortality rates have been 25 percent.”
To watch a video of the Senate hearing or to read Califf’s written testimony, click here.