Diagnosis of malaria by detection of Plasmodium falciparum HRP-2 antigen with a rapid dipstick antigen-capture assay.
Two field studies in Kenya and an experimental challenge study in the USA were done to assess the accuracy of a dipstick antigen-capture assay based on qualitative detection of Plasmodium falciparum histidine-rich protein 2 (PfHRP-2) in peripheral blood for diagnosis of P falciparum infection. In these studies, the assay was 96.5-100% sensitive for detection of greater than 60 P falciparum asexual parasites/microL blood, 70-81% sensitive for 11-60 parasites/microL blood, and 11-67% sensitive for 10 parasites or less/microL blood. Specificity was 95% (95% CI 85-105%; n = 20) among naive American volunteers, 98% (96-101%; n = 112) among volunteers exposed to the bite of P falciparum-infected mosquitoes, and 88% (84-92%; n = 285) among Kenyans living in an area with holoendemic malaria. Our results also indicated that PfHRP-2 antigen was not detectable in blood 6 days after initiation of curative chemotherapy, and suggest that such circulating antigens rarely lead to false-positive tests. The dipstick assay's sensitivity, specificity, simplicity, and speed may make it an important tool in the battle against malaria.
Beadle
C
C
Malaria Program, Naval Medical Research Institute, Rockville, MD 20852-1820.
Long
G W
GW
Weiss
W R
WR
McElroy
P D
PD
Maret
S M
SM
Oloo
A J
AJ
Hoffman
S L
SL
D000293:Adolescent; D000328:Adult; D000818:Animals; D000953:Antigens, Protozoan / Q000097:blood*; D002648:Child; D005260:Female; D006801:Humans; D016778:Malaria, Falciparum / Q000175:diagnosis* / Q000276:immunology; D008297:Male; D010963:Plasmodium falciparum / Q000276:immunology*; D011237:Predictive Value of Tests; D015800:Protozoan Proteins / Q000097:blood*; D011934:Reagent Strips; D012680:Sensitivity and Specificity
D000953:Antigens, Protozoan; D015800:Protozoan Proteins; D011934:Reagent Strips