CDC wants faster testing for bird flu in hospitals

Hospitals should expand and speed up testing of people hospitalised with influenza to see if they are suffering from bird flu, according to the Centers for Disease Control and Prevention (CDC).

The agency is now recommending that testing for the H5N1 strain of bird flu currently decimating wild and domesticated bird populations around the world and causing a major outbreak in US cattle should be carried out within 24 hours as part of a ramp-up of efforts to guard against a potential epidemic.

The action comes amid increasing numbers of H5N1 infections in humans – and the first fatality from bird flu in the US earlier this month – although, the CDC has stressed that it still thinks that the overall risk to the public is low.

"Clinicians and laboratorians are reminded to test for influenza in patients with suspected influenza and, going forward, to now expedite the subtyping of influenza A-positive specimens from hospitalised patients, particularly those in an intensive care unit (ICU)," it said in a health advisory.

"This approach can help prevent delays in identifying human infections with avian influenza A(H5N1) viruses, supporting optimal patient care and timely infection control and case investigation," it added.

Previously, hospitals in the US would usually save up batches of samples from flu patients and send them to government labs for subtyping every few days, and by the time results are available patients will often have been discharged, making follow-up difficult. Moreover, the CDC acknowledges that not all patients hospitalised with flu are tested.

Since 2022, a total of 67 human cases of bird flu infection have been identified in the US, with all but one of those cases occurring in 2024. Those cases are thought to have been caused by either exposure to animals or consumption of poorly cooked meat, although three cases have no known cause. Still, there is no evidence of direct human-to-human transmission, which would be needed for an epidemic to occur.

More rapid testing would make it easier to monitor sources of infection and allow family members and other associates of people found to have H5N1 to be tested and – if appropriate – to receive treatment with antiviral drugs like oseltamivir.

The most recent update from the CDC on influenza indicates that more than 37,000 patients were admitted to hospital with flu in the week ending 4th January.

Photo by Mufid Majnun on Unsplash