Four farmworkers in Washington state have suspected cases of bird flu after working to remove carcasses from a farm where around 800,000 chickens were culled. The Centers for Disease Control and Prevention is sending a team to the state to investigate the suspected infections, reports Reuters. If confirmed, the cases will make Washington the sixth state, after California, Colorado, Michigan, Missouri, and Texas, to have confirmed human cases of the virus. Washington's health department said the workers were part of a crew cleaning up at a farm where chickens were culled after they were infected by wild birds. Officials say the workers had mild respiratory symptoms and conjunctivitis, aka pinkeye.
The workers had protective gear, but their use of it was inconsistent, authorities say. The suspected cases bring the total in the US to 31. All the cases were linked to infected poultry and cattle apart from a case in Missouri that has puzzled researchers, NBC News reports. Authorities say there's no evidence of transmission between humans, but they're worried that could change. "The longer this virus hangs out in the environment, the more animals it spills over into, the more it changes in ways we don't understand or predict, the more concerned we are going to be that this becomes the next global pandemic," said Dr. Amber Itle, the Washington state veterinarian.
Experts are worried about what could happen if people get infected with bird flu and seasonal influenza at the same time. "You don't want people affected with the seasonal flu virus to get a virus from animals and for those viruses to potentially recombine," Dr. Peter Rabinowitz, a professor of environmental and occupational health sciences at the University of Washington, tells NBC News. "This is a wakeup call," he says. "We need to do a better job of protecting workers." The CDC is providing free seasonal flu vaccines to farmworkers in a dozen states, including California and Texas. (More bird flu stories.)