CDC Confirms First Bird Flu Infection in Missouri Resident With No Animal Contact

Casim Abbas feeds chickens at his small egg farm at his home in Williamston, Mich., on Feb. 8, 2023. Matthew Hatcher/AFP via Getty Images

Missouri has detected its first human case of bird flu in a patient who had no known contact with an infected animal, the U.S. Centers for Disease Control and Prevention (CDC) said on Friday.

This is the first time a patient who did not work with any poultry or dairy farms has tested positive for bird flu, and it is the 14th human bird flu case reported in the United States this year.

The case was detected through Missouri’s seasonal flu surveillance system, according to a CDC press release.

The patient, who had underlying health conditions, was hospitalized on Aug. 22. The CDC said a sample was sent to the agency, where it was confirmed to be the H5 subtype, also known as avian influenza A or bird flu.

The Missouri Department of Health and Senior Services said the patient has since recovered and been discharged from the hospital. No transmission of the virus has been identified among the patient’s close contacts.

State health officials did not provide details on how the patient contracted the virus or what symptoms they experienced.

The CDC said the risk to the general public from avian flu remains low.

“The results of this investigation will be particularly important in light of the current lack of an obvious animal exposure,” the agency said in a statement.

“It is important to note that, while rare, there have been novel influenza A cases where an animal source cannot be identified.”

Missouri has not reported any H5 infections in dairy cattle, although there have been some cases reported in commercial poultry or backyard flocks and wild birds, according to the CDC.

The state health department said there has been no sign of unusual influenza activity in people, including no increase in emergency room visits or laboratory detection of human influenza cases in Missouri.

As of Sept. 3, the bird flu virus has affected at least 196 dairy herds in 14 states across the country, according to the CDC.

The CDC announced in July a $5 million initiative to offer seasonal flu vaccines to livestock workers in a bid to reduce the risk of potential co-infection of both seasonal influenza and bird flu virus in farm workers.

Infection with both viruses could lead to a genetic reassortment, where genetic material from the two influenza viruses mixes and creates a new influenza virus, according to the agency.

“In theory, reassortment could lead to a new influenza A virus that could pose a significant public health concern by becoming more efficient at spread and potentially more severe. A virus that has the transmissibility of seasonal influenza and the severity of H5N1,” the CDC’s principal deputy director, Nirav Shah, said during a July 30 press call.

Shah acknowledged that dual infections are rare but said the agency aims “to do everything we can” to reduce the risk of a new virus emerging from such infections.