United States: Federal health officials are urging farmworkers to be tested for bird flu, even if they don’t feel sick. A new study found some dairy workers showed signs of infection without any symptoms. Experts say workers who are around infected animals should get tested and treated to stay safe. 

The new guidance comes after 115 farmworkers in Michigan and Colorado underwent blood tests to determine that eight of the workers – or 7 percent — had antibodies indicative of past exposure to the virus, also known as Type A H5N1 influenza. “The intent of these measures is to protect workers, to prevent cross species transmission of H5 to humans and to mitigate the risk of the virus mutating,” explained Shah to reporters. 

As reported by Associated Press, the CDC study gives the largest look so far at how the bird virus first identified in March in dairy cows is infecting people. This means that the virus has affected more humans than the forty-six farmworkers who were infected in the United States by Thursday. 98% had exposure to infected dairy cows or infected poultry. 

Experts not involved in the study said it was remarkable that the research raised new actions needed by CDC. Earlier guidelines prescribed to test and treat employees that are symptomatic. 

“This is a move towards the assessment that these H5N1 viruses pose a greater risk than the CDC estimated before,” charged Dr. Gregory Gray of the University of Texas’ Medical Branch in Galveston, a specialist in infectious diseases. 

Each new infection within animals or humans potentially allows the virus to evolve in a way that is risky, said Angela Rasmussen, a virus expert at the University of Saskatchewan in Canada. 

“It shows yet again that we are not responding effectively to the H5N1 cattle outbreak in humans or animals and if we continue to let this virus spread and jump from species to species, our luck will eventually run out,” Rasmussen said in an email. 

The CDC investigation involved 45 workers in Michigan as well as 70 in Colorado, all of whom were tested between June and August. When looking at the eight workers whose blood tested positive for alcohol the four still claimed not to have any symptoms.