US confirms first bird flu case without animal contact

WASHINGTON - A person in the state of Missouri has become the first in the US to test positive for bird flu without a known exposure to infected animals, the authorities said on Sept 6.

The adult patient, who has underlying conditions, was admitted to hospital on Aug 22, received antiviral medications against influenza, then recovered and was discharged, according to statements from the Centres for Control and Disease Prevention (CDC) and the Missouri Department of Health and Senior Services.

Since the patient’s flu type appeared suspicious on an initial test, it was sent for additional testing in state and federal laboratories, which revealed it was H5, also known as avian flu or bird flu.

The person was the 14th to test positive for bird flu in the US in 2024, and the first without known contact with animals.

“No H5 infection in dairy cattle has been reported in Missouri,” said the Missouri health department, though “some H5 cases in commercial or backyard flocks and wild birds have been reported”.

All previous bird flu cases in the US have been among farmworkers, including the very first in 2022.

Bird flu is most commonly found in wild birds and poultry, but has more recently been detected in mammals, with a cattle outbreak seen across the country in 2024. It can occasionally infect humans through close contact or contaminated environments.

While the CDC continues to assess the risk to the public as low, “circumstances may change quickly as more information is learnt”, it said.

In the decades since H5 has been found in humans, there have been rare cases where an animal source cannot be identified, but there has so far not been evidence of sustained human-to-human transmission, which would significantly increase the threat level. AFP