CDC and researchers reveal inconsistencies with rapid influenza tests

Avatar By Le Williams | 2 years ago

A study abstract compiled by the Centers for Disease Control and Prevention has been confirmed by a group of researchers involving rapid influenza antigen tests (RIATs) proven as untrustworthy due to extreme low sensitivity attributes.

According to the abstract presented Sunday at the ASM Microbe 2018 conference, 50% of patients infected with influenza may have had prolonged illness if they were initially misdiagnosed as flu-free and did not receive the proper treatment.

Anthony Fauci, director, National Institute of Allergy and Infectious Diseases stated, “You have to be careful about relying heavily upon rapid flu tests.” Additionally, Fauci told Axios that clinicians and patients should rely upon nasal swabs that look for influenza viral RNA, nucleic acids or have their patient samples cultured for a couple days.

“Nonetheless, treatment should not wait for cultured analysis,” Fauci added.

Taiwanese intensive care unit doctors require virus cultures at the same time as RIATs. The team analyzed the results for 307 patients with laboratory-confirmed influenza admitted to ICUs over a 10-year period, from August 2009 to July 2017.

“Decision-making based on RIAT is strongly discouraged and prompt empiric antiviral medication is justified in severe respiratory infection,” the researchers say in the abstract.

Out of the 307 cases, RIAT was checked for 259, and of those, 126 or 49% were wrongly labeled.

Patients who had tested negative for influenza using the RIAT, when compared to the RIAT-positive patients, had a longer average ICU stay of 12 days. This compared to an average length of stay of just 9 days for those labeled immediately positive.

The FDA recently reclassified rapid flu tests, requiring new purchases to meet the minimum of more than 80% sensitivity.