A person has been hospitalized with bird flu in Louisiana, according to the Centers for Disease Control and Prevention (CDC), marking the first time since the outbreak began that an infection with the H5N1 virus reached such severity. Although another severe case hospitalized in a teenager in Canada last month, this is the first severe case reported in the U.S.
This case brings this outbreak's total number of human infections to 61, though many cases may be going uncounted. Most of these infections occur among farmworkers who come into contact with dairy cows and poultry, which the virus is infecting and massacring in massive numbers. This week, seven more outbreaks were reported among Californian dairy herds, bringing the total number of herds affected across the country to 860. More than 123 million poultry and more than 10,000 wild birds (with 300 million dead birds worldwide) have been affected.
The case in Louisiana — along with recent cases in Washington state and in the Canadian patient with severe illness — involves a type of the virus that has recently been detected in wild birds in the U.S. and it is different from another type that is circulating in dairy cows.
This week, the CDC also announced another probable case of bird flu in a person in Delaware. The source of infection is being investigated, but if confirmed, this would indicate the virus is continuing to increase its geographical range. Most cases in the U.S. have occurred in California and Colorado, but it has not yet reached the Northeast. Another presumptive case was reported in Wisconsin today, a first for the state.
Public health officials have not been able to identify the source of three cases of bird flu detected in a person in Missouri, a child in California, and the teen in Canada. Although the source of infection for the person in Louisiana has not been confirmed, they did come into contact with dead birds in backyard flocks. This is the first infection known to have occurred among someone exposed like this in the U.S., although backyard flocks have been infected in places like Oregon.
Another possible means of transmission is through drinking raw milk from cows infected with the virus. After the virus was detected in raw milk sold in California last month, the U.S. Department of Agriculture ordered raw milk manufacturers to ramp up testing as well as recalling some raw milk from stores.
