CDC: 'Close contact' of Mo. bird flu patient also fell ill, but human transmission unlikely

Sept. 14 (UPI) -- A close contact of a Missouri resident identified as having a human case of the H5N1 avian flu also became sick around the same time, the Centers for Disease Control and Prevention has revealed.

According to a CDC avian flu update issued Friday, an investigation of last week's mysterious case of the Missouri bird flu patient found that a "household contact" of the patient also became ill with similar symptoms on the same day. That person was not tested for the avian flu and his since recovered.

The CDC probe also found that a second close contact of the Missouri patient, identified as a health care worker, similarly developed "mild symptoms" and tested negative for flu.

Despite the multiple illnesses, the agency has determined there was no human-to-human transmission of the H5N1 virus, which has been circulating among poultry and wild birds since 2022 and made the interspecies jump to dairy cows earlier this year.

"The simultaneous development of symptoms does not support person-to-person spread but suggests a common exposure," the CDC said.

The agency's update also confirmed that genetic tests performed on the virus from the Missouri patient determined it is closely related to the strain found in dairy cattle, thus deepening the question of how the person contracted the infection. The case marked the first instance of the virus in someone without a known occupational exposure to sick or infected animals.

It was the 14th overall human case of H5N1 reported in the nation.

The Missouri patient was hospitalized on Aug. 22, underwent testing and was treated before being released, according to the Missouri Department of Health and Senior Services .

Dr. Dana Hawkinson, the medical director for infection prevention and control at the University of Kansas Health System, told the Kansas City Star a pet could be responsible for the infection.

"I think household pets are probably a fairly good, plausible explanation for this," he said. "In general we just don't have a lot of information about this case."