The Role of Serological and Molecular Tools in Evaluating Performance of Malaria Control Programs in Ethiopia
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Date
2018-09-01
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Addis Ababa University
Abstract
The global drop in malaria mortality (60%) and morbidity (37%) rates were recorded in 2015 from the 2000 baseline. But in 2016, approximately 5 million more new cases were recorded globally compared to 2015. The same trend was reported in Ethiopia during the same period. These facts underline the need to continuously monitor control programs as we move to malaria elimination, by using improved diagnostic tools than standard diagnostics, Microscopy and rapid diagnostic test (RDT). Thus, this study was designed with the objective; to evaluate seroconversion as readout for the effectiveness of malaria control program and determine the ongoing malaria infection prevalence based on nested polymerase reaction (nPCR) and microscopy. A cross-sectional study was done using a multistage sampling technique to select and enroll 1144 participants from Babile district. Retrospective malaria control program, socio-demographic data and finger pricks were collected. Serology, 18s nPCR and smear microscopy was done at Armauer Hansen research institute. Data were entered into MS-Excel and Statistical analysis was done using STATA 13 and Graph Pad Prism 5.0. Simple reverse catalytic model, profile likelihood test, reverse cumulative distribution (RCD), Kappa and receiver operating characteristic (ROC) tests were done and all the comparisons were considered as statistically significant at a P value <0.05. The 12 years retrospective data showed progressive decline in both malaria cases (33.4% to 2.9%) from 2005 to 2016. The obtained malaria-positivity was 1.84% (21/1144), 7.96% (91/1144) and 21.6% by microscopy, nPCR and serology. The serology showed changes in transmission occurred approximately 15.5 and 11.5 years ago for PfAMA-1 and PvAMA-1 respectively. Serology and 18s targeted nPCR showed higher efficiency to detect submicroscopic and asymptomatic parasitemia in low transmission settings. Therefore, these tools should be used before the commencement of the elimination program than light microscopy.
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Malaria Elimination, Serology, Current Infection, Malaria Metrics