Plasmodium falciparum parasite infection prevalence from a household survey in Zambia using microscopy and a rapid diagnostic test: Implications for monitoring and evaluation

• Published in: Acta tropica Vol. 112; no. 3; pp. 277 - 282
• Main Authors: Keating, Joseph, Miller, John M., Bennett, Adam, Moonga, Hawela B., Eisele, Thomas P.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 01.12.2009; Elsevier
• Subjects: Animals; Biological and medical sciences; Child, Preschool; Family Characteristics; Female; General aspects; Human protozoal diseases; Humans; Infant; Infant, Newborn; Infectious diseases; Malaria; Malaria, Falciparum - diagnosis; Malaria, Falciparum - epidemiology; Male; Medical sciences; Microscopy; Microscopy - methods; Molecular Diagnostic Techniques - methods; Monitoring and evaluation; Parasitic diseases; Plasmodium falciparum - isolation & purification; Population-based survey; Prevalence; Protozoal diseases; RDT; Sensitivity and Specificity; Zambia; Zambia - epidemiology; Zambia; Africa; Zambia; RDT; Monitoring and evaluation; Microscopy; Malaria; Population-based survey; Protozoa; Apicomplexa; Protozoal disease; Prevalence; Parasite; Parasitosis; Epidemiology; Infection; Plasmodium falciparum; Survey; Rapid technique; Surveillance; Tropical medicine; Diagnosis
• ISSN: 0001-706X; 1873-6254
• DOI: 10.1016/j.actatropica.2009.08.011

This paper presents estimates of P. falciparum infection prevalence in children under 5 years old in the context of a population-based household survey in Luangwa District (Lusaka Province), Zambia, an area where greater than 75% of households possess at least one insecticide-treated mosquito net (ITN). The sensitivity and specificity of an HRP-2 rapid diagnostic test (RDT) (ICT Malaria Pf ®) compared to microscopy, as well as factors associated with discordant diagnostic results are also presented. P. falciparum infection prevalence was estimated at 7.0% (95% CI 4.9–9.0%) using microscopy. Using microscopy as the gold standard, the sensitivity of the HRP-2 RDT was 100% and specificity was 91.5%; positive predictive value was estimated to be 46.7% (95% CI 36.3–57.4%). RDT discordance, or HRP-2 false positivity, was highest among older children, those in the northern part of Luangwa District, and those with a reported history of antimalarial treatment. These data suggest microscopy should remain the gold standard for estimating malaria parasite point prevalence from household surveys for monitoring and evaluation purposes.