Rapid flu test falls short in detecting H1N1

Identifying pandemic H1N1 flu in children may not be as easy as administering rapid influenza tests, some of which have been shown to have poor sensitivity for H1N1 flu detection, 2 studies published in the March issue of Pediatrics found.

In an analysis of 1 rapid influenza diagnostic test (RIDT) for H1N1 flu, researchers found a sensitivity of 45%. There was 62% sensitivity with the same test in a second study.

"Although a positive rapid influenza diagnostic test result was highly accurate in predicting infection with influenza type A H1N1 2009 in children, a negative RIDT result did not preclude a child having H1N1," the authors of the first study reported.

In a second study, which enrolled 820 children aged 17 years and younger (median age, 3.4 years), there was a higher sensitivity among patients aged 5 years or younger than in older children (P=.003).