More states are finding bird flu in cattle, raising concerns about potential risks to humans. The outbreak of bird flu in dairy cattle is still unfolding, with North Carolina and South Dakota detecting the virus in dairy herds, bringing the total number of affected states to eight.

Researchers are closely monitoring the situation, trying to understand what mutations could make the virus a threat to humans. There is some reassuring news so far, as scientists from the U.S. Department of Agriculture have stated that the virus is not presenting like a respiratory illness in cattle, indicating that the animals don’t appear to be shedding large amounts of the virus from their nose or mouths.

Instead, federal health officials suspect some form of ‘mechanical transmission’ is responsible for spreading the virus within the herd, possibly occurring during the process of milking the cows. High concentrations of the virus are being found in the milk, supporting this theory.

While the samples collected from infected animals do not suggest radical changes in the virus, scientists are on the lookout for specific signs of trouble in the virus genome as it spreads to more mammals. Genetic sequencing of the virus in a Texas dairy worker showed a mutation in a gene, PB2, commonly affected when the virus infects mammals, indicating potential evolution to better replicate inside a mammal.

Experts emphasize the need to stay vigilant as the virus could potentially evolve to infect humans more easily. The situation is being closely monitored by researchers, with concerns that the virus may reach a point where it poses a significant risk to human health.