Infectious Disease
Varying Malaria Rapid Diagnostic Test Accuracy by Regional Transmission Level and Demographics in Mainland Tanzania Danielle Wiener* Danielle Wiener Zachary R. Popkin-Hall Misago D. Seth Rashid A. Madebe Rule Budodo Dativa Pereus Catherine Bakari Sijenunu Aaron Daniel Mbwambo Abdallah Lusasi Stella Kajange Samwel Lazaro Ntuli Kapologwe Celine I. Mandara Jeffrey A. Bailey Jonathan J. Juliano Timothy P. Sheahan Deus Ishengoma
A cornerstone of malaria control is accurate diagnosis and rapid treatment, which predominantly relies on point-of-care effective malaria rapid diagnostic tests (RDTs). This is of particular importance in Tanzania, where overall cases remain high, but where transmission intensity can vary from very low to very high depending on the district/region. Thus, it is important to quantify the accuracy of these tests across different transmission settings and by different demographic groups. Clarifying how RDT results differ from qPCR results, and the nature of additional variance in sensitivity and specificity by test manufacturer, will be useful for reducing outcome misclassification when studying malaria prevalence and optimizing their routine use. We compared 3 national standard histidine rich protein 2 (HRP2) based RDTs (Care Start, First Response, and SD Bioline), and a research RDT based on detection of lactate dehydrogenase (Rapigen) to qPCR. Data were collected in a nation-wide survey in 2021 covering 10 of the 26 regions in Mainland Tanzania from the four strata of high, moderate, low and very low transmission intensities. We found differences by age, gender and regional transmission rate of malaria. The research RDT had overall low performance, with the lowest sensitivity across the 4 designated transmission strata (very low: 0.66, low: 0.82, moderate: 0.82, high: 0.68) and across most demographic subgroups (range: 0.70-0.82). Additionally, negative predictive value was low for all tests in moderate to high transmission regions (range: 0.52-0.78). These results offer pertinent information on test accuracy and reliability, compare a new RDT to current national standard RDTs in Tanzania, and decrease outcome misclassification for malaria prevalence estimates.
