Evaluation of light microscopy and rapid diagnostic test for the detection of malaria under operational field conditions: a household survey in Ethiopia
Open Access
- 3 July 2008
- journal article
- research article
- Published by Springer Science and Business Media LLC in Malaria Journal
- Vol. 7 (1), 118
- https://doi.org/10.1186/1475-2875-7-118
Abstract
Background In most resource-poor settings, malaria is usually diagnosed based on clinical signs and symptoms and not by detection of parasites in the blood using microscopy or rapid diagnostic tests (RDT). In population-based malaria surveys, accurate diagnosis is important: microscopy provides the gold standard, whilst RDTs allow immediate findings and treatment. The concordance between RDTs and microscopy in low or unstable transmission areas has not been evaluated. Objectives This study aimed to estimate the prevalence of malaria parasites in randomly selected malarious areas of Amhara, Oromia, and Southern Nations, Nationalities and Peoples' (SNNP) regions of Ethiopia, using microscopy and RDT, and to investigate the agreement between microscopy and RDT under field conditions. Methods A population-based survey was conducted in 224 randomly selected clusters of 25 households each in Amhara, Oromia and SNNP regions, between December 2006 and February 2007. Fingerpick blood samples from all persons living in even-numbered households were tested using two methods: light microscopy of Giemsa-stained blood slides; and RDT (ParaScreen device for Pan/Pf). Results A total of 13,960 people were eligible for malaria parasite testing of whom 11,504 (82%) were included in the analysis. Overall slide positivity rate was 4.1% (95% confidence interval [CI] 3.4–5.0%) while ParaScreen RDT was positive in 3.3% (95% CI 2.6–4.1%) of those tested. Considering microscopy as the gold standard, ParaScreen RDT exhibited high specificity (98.5%; 95% CI 98.3–98.7) and moderate sensitivity (47.5%; 95% CI 42.8–52.2) with a positive predictive value of 56.8% (95% CI 51.7–61.9) and negative predictive value of 97.6% (95% CI 97.6–98.1%) under field conditions. Conclusion Blood slide microscopy remains the preferred option for population-based prevalence surveys of malaria parasitaemia. The level of agreement between microscopy and RDT warrants further investigation in different transmission settings and in the clinical situation.Keywords
This publication has 14 references indexed in Scilit:
- Integrating an NTD with One of “The Big Three”: Combined Malaria and Trachoma Survey in Amhara Region of EthiopiaPLoS Neglected Tropical Diseases, 2008
- Rapid Diagnostic Tests for Malaria at Sites of Varying Transmission Intensity in UgandaThe Journal of Infectious Diseases, 2008
- A Review of Malaria Diagnostic Tools: Microscopy and Rapid Diagnostic Test (RDT)The American Journal of Tropical Medicine and Hygiene, 2007
- An exploratory study of factors that affect the performance and usage of rapid diagnostic tests for malaria in the Limpopo Province, South AfricaMalaria Journal, 2007
- Meta-Analysis: Accuracy of Rapid Tests for Malaria in Travelers Returning from Endemic AreasAnnals of Internal Medicine, 2005
- Association between climate variability and malaria epidemics in the East African highlandsProceedings of the National Academy of Sciences of the United States of America, 2004
- Self-treatment of malaria in rural communities, Butajira, southern Ethiopia.2003
- Rapid Diagnostic Tests for Malaria ParasitesClinical Microbiology Reviews, 2002
- Community participation in malaria control in Tigray region EthiopiaActa Tropica, 1996
- Plasmodium vivax and P. falciparum epidemiology in Gambella, south-west Ethiopia.1992