Traditionally to rule out a diagnosis of malaria requires three negative blood films. But in the era of routine rapid diagnostic testing, some are questioning the need for continued serial testing. A new study, published online Dec. 3 in theAmerican Journal of Tropical Medicine and Hygiene, shows that for patients not taking anti-malarial therapy nearly all malaria diagnosis are made with the initial blood film and rapid diagnostic test, possibly obviating the need to continue serial testing. Australian researchers examined 255 cases of malaria diagnosed from 1999 to 2010 at three laboratories in a nonendemic area. Standard operating procedures at the three labs require that all clinical requests for thick and thin blood films for malaria also have a reflex rapid diagnostic testing performed (BinaxNOW immunochromatographic test). Plasmodium falciparum malaria was diagnosed on the first diagnostic set in all but one case (99 percent), while initial tests detected more than 97 percent of cases for non–P. falciparum malaria. Nine cases of malaria (3.5 percent) had negative results for the initial blood film and rapid diagnostic test but were diagnosed on the second film. The researchers say that each of the missed cases was atypical with four of the patients having […]