Serology reveals heterogeneity of Plasmodium falciparum transmission in northeastern South Africa : implications for malaria elimination

Show simple item record Biggs, Joseph Raman, Jaishree Cook, Jackie Hlongwana, Khumbulani Drakeley, Chris Morris, Natashia Serocharan, Ishen Agubuzo, Eunice Kruger, Philip Mabuza, Aaron Zitha, Alpheus Machaba, Elliot Coetzee, Maureen Kleinschmidt, Immo 2017-02-16T06:32:17Z 2017-02-16T06:32:17Z 2017-01
dc.description Additional file 1. Box plots of antibody responses, in the form of optical density (OD) values, for both PfAMA-1 and PfMSP-119 among different ages/age bands across the entire study site. Hollow black circles represent outlier OD responses. Red lines correspond to seropositive cut-offs, which equate to 0.067 for PfAMA-1 and 0.103 for PfMSP-119. en_ZA
dc.description Additional file 2. Age-seroprevalence to either PfAMA-1 or PfMSP-119 among sampled participants of both Ba-Phalaborwa and Bushbuckridge. Red triangles: observed age-seroprevalence; solid lines: predicted seroprevalence; dotted lines: predicted seroprevalence upper and lower 95% confidence intervals. en_ZA
dc.description Additional file 3. Demographic and risk factors associated with seroprevalence to either PfAMA-1 and PfMSP-119. en_ZA
dc.description.abstract BACKGROUND : It is widely acknowledged that modifications to existing control interventions are required if South Africa is to achieve malaria elimination. Targeting indoor residual spraying (IRS) to areas where cases have been detected is one strategy currently under investigation in northeastern South Africa. This seroprevalence baseline study, nested within a targeted IRS trial, was undertaken to provide insights into malaria transmission dynamics in South Africa and evaluate whether sero-epidemiological practices have the potential to be routinely incorporated into elimination programmes. METHODS : Filter-paper blood spots, demographic and household survey data were collected from 2710 randomly selected households in 56 study wards located in the municipalities of Ba-Phalaborwa and Bushbuckridge. Blood spots were assayed for Plasmodium falciparum apical membrane antigen-1 and merozoite surface protein-119 bloodstage antigens using an enzyme linked immunosorbent assay. Seroprevalence data were analysed using a reverse catalytic model to determine malaria seroconversion rates (SCR). Geospatial cluster analysis was used to investigate transmission heterogeneity while random effects logistic regression identified risk factors associated with malaria exposure. RESULTS : The overall SCR across the entire study site was 0.012 (95% CI 0.008–0.017) per year. Contrasting SCRs, corresponding to distinct geographical regions across the study site, ranging from <0.001 (95% CI <0.001–0.005) to 0.022 (95% CI 0.008–0.062) per annum revealed prominent transmission heterogeneity. Geospatial cluster analysis of household seroprevalence and age-adjusted antibody responses detected statistically significant (p < 0.05) spatial clusters of P. falciparum exposure. Formal secondary education was associated with lower malaria exposure in the sampled population (AOR 0.72, 95% CI 0.56–0.95, p = 0.018). CONCLUSIONS : Although overall transmission intensity and exposure to malaria was low across both study sites, malaria transmission intensity was highly heterogeneous and associated with low socio-economic status in the region. Findings suggest focal targeting of interventions has the potential to be an appropriate strategy to deploy in South Africa. Furthermore, routinely incorporating sero-epidemiological practices into elimination programmes may prove useful in monitoring malaria transmission intensity in South Africa, and other countries striving for malaria elimination. en_ZA
dc.description.department UP Centre for Sustainable Malaria Control (UP CSMC) en_ZA
dc.description.librarian am2017 en_ZA
dc.description.uri en_ZA
dc.identifier.citation Biggs, J, Raman, J, Cook, J, Hlongwana, K, Drakeley, C, Morris, N, Serocharan, I, Agubuzo, E, Kruger, P, Mabuza, A, Zitha, A, Machaba, E, Coetzee, M & Kleinschmidt, I 2016, 'Serology reveals heterogeneity of Plasmodium falciparum transmission in northeastern South Africa : implications for malaria elimination', Malaria Journal, vol. 16, art. no. 48, pp. 1-13. en_ZA
dc.identifier.issn 1475-2875
dc.identifier.other 10.1186/s12936-017-1701-7
dc.language.iso en en_ZA
dc.publisher BioMed Central en_ZA
dc.rights © The Author(s) 2017. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License. en_ZA
dc.subject Malaria transmission en_ZA
dc.subject Indoor residual spraying (IRS) en_ZA
dc.subject Seroconversion rates (SCR) en_ZA
dc.subject South Africa (SA) en_ZA
dc.title Serology reveals heterogeneity of Plasmodium falciparum transmission in northeastern South Africa : implications for malaria elimination en_ZA
dc.type Article en_ZA

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