The reliability of diagnostic techniques in the diagnosis and management of malaria in the absence of a gold standard.
The accuracy of techniques for the diagnosis of malaria are usually compared with optical microscopy, which is considered to be a gold standard. However, microscopy is prone to error and therefore makes it difficult to assess the reliability of other diagnostic techniques. We did a systematic review to assess the specificity and sensitivity of diagnostic techniques in different settings, using a statistical method that avoided defining a gold standard. Performance varied depending on species of the malaria parasite, level of parasitaemia, and immunity. Overall, histidine-rich protein 2 (HRP2)-based dipsticks showed a high sensitivity (92.7%) and specificity (99.2%) for Plasmodium falciparum in endemic areas. The acridine orange test was more sensitive (97.1%) in detecting P falciparum in epidemiological studies, with a specificity of 97.9%. In the absence of a gold standard, HRP2 dipsticks and acridine orange could provide an alternative for detecting falciparum infections in endemic areas and epidemiological studies, respectively. Microscopy still remains more reliable in detecting non-falciparum infections.
Ochola
L B
LB
Centre for Geographic Medicine Research, KEMRI, Kilifi, Kenya. lochola@kilifi.kemri-wellcome.org
Vounatsou
P
P
Smith
T
T
Mabaso
M L H
ML
Newton
C R J C
CR
D000818:Animals; D006801:Humans; D008288:Malaria / Q000175:diagnosis* / Q000628:therapy*; D008853:Microscopy / Q000592:standards; D018579:Patient Selection; D010961:Plasmodium / Q000302:isolation & purification*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity