Molecular dipstick test for diagnosis of sleeping sickness.
Human African trypanosomiasis (HAT) or sleeping sickness is a neglected disease that affects poor rural populations across sub-Saharan Africa. Confirmation of diagnosis is based on detection of parasites in either blood or lymph by microscopy. Here we present the development and the first-phase evaluation of a simple and rapid test (HAT-PCR-OC [human African trypanosomiasis-PCR-oligochromatography]) for detection of amplified Trypanosoma brucei DNA. PCR products are visualized on a dipstick through hybridization with a gold-conjugated probe (oligochromatography). Visualization is straightforward and takes only 5 min. Controls both for the PCR and for DNA migration are incorporated into the assay. The lower detection limit of the test is 5 fg of pure T. brucei DNA. One parasite in 180 microl of blood is still detectable. Sensitivity and specificity for T. brucei were calculated at 100% when tested on blood samples from 26 confirmed sleeping sickness patients, 18 negative controls (nonendemic region), and 50 negative control blood samples from an endemic region. HAT-PCR-OC is a promising new tool for diagnosis of sleeping sickness in laboratory settings, and the diagnostic format described here may have wider application for other infectious diseases.
Deborggraeve
S
S
Department of Parasitology, Institute of Tropical Medicine, Nationalestraat 155, B-2000 Antwerpen, Belgium. sdeborggraeve@itg.be
Claes
F
F
Laurent
T
T
Mertens
P
P
Leclipteux
T
T
Dujardin
J C
JC
Herdewijn
P
P
Büscher
P
P
D000818:Animals; D001483:Base Sequence; D001769:Blood / Q000469:parasitology; D016054:DNA, Protozoan / Q000032:analysis* / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D025202:Molecular Diagnostic Techniques; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000379:methods*; D012015:Reference Standards; D012680:Sensitivity and Specificity; D014346:Trypanosoma brucei brucei / Q000235:genetics / Q000302:isolation & purification*; D014353:Trypanosomiasis, African / Q000175:diagnosis*
D016054:DNA, Protozoan