Third person tests positive in dairy cattle outbreak
(CNN) — A third person in the United States has tested positive for the H5 avian influenza virus, the Michigan Department of Health and Human Services said Thursday. This is the second case reported in Michigan in the ongoing outbreak of the virus.
This time, in addition to the eye symptoms seen in other recent human infections with the virus, the farm worker had a cough and other respiratory symptoms that are more typical of human influenza infections, the health department said.
Experts familiar with the case said the addition of respiratory symptoms does not necessarily indicate that the virus has become more dangerous or that it can spread more easily from person to person.
Instead, they say the person likely developed symptoms in the lungs due to the route of infection, possibly from inhaling infectious aerosols in the milking parlor instead of rubbing their eyes with contaminated hands.
“In the first case in Michigan, eye symptoms occurred after contaminated milk came into direct contact with the eyes. In this case, respiratory symptoms occurred after direct contact with an infected cow,” Dr. Natasha Bagdasarian, Michigan’s chief medical officer, said in a press release.
“None of the people were wearing full personal protective equipment (PPE). This tells us that direct contact with infected livestock poses a risk to people and that PPE is an important tool in preventing the spread of infection among people working in dairy and poultry plants. “We have seen no evidence of sustained human-to-human transmission of the virus and the current risk to public health remains low.”
The U.S. Centers for Disease Control and Prevention said the risk to the general population is low, according to a health department statement.
Research is being done into how infections are transmitted between cows and from cows to the people who work with them.
This is the third human infection caused by this highly pathogenic form of avian influenza currently affecting dairy cattle in the United States. None of the three people had contact with each other, but they all worked with livestock, suggesting that these were cases of cow-to-human transmission. Two other cases were associated with eye infections or conjunctivitis.
The person had direct contact with infected livestock and notified local health officials that they were feeling ill. Its symptoms are described as mild.
The Michigan Department of Health recommends that people who work on poultry or dairy farms get the seasonal flu vaccine.
“This will not prevent infection with avian influenza viruses, but may reduce the risk of co-infection with avian influenza and influenza viruses,” the health department said.