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

Malaria Journal

Research

Maureen Coetzee¹  Eunice Agubuzo¹  Jaishree Raman²  Chris Drakeley³  Joseph Biggs³  Natashia Morris⁴  Ishen Serocharan⁴  Elliot Machaba⁵  Philip Kruger⁵  Aaron Mabuza⁶  Alpheus Zitha⁶  Khumbulani Hlongwana⁷  Jackie Cook⁸  Immo Kleinschmidt⁹ 

[1] Centre for Opportunistic Tropical and Hospital Infections, National Institute for Communicable Diseases, Johannesburg, South Africa;Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa;Centre for Opportunistic Tropical and Hospital Infections, National Institute for Communicable Diseases, Johannesburg, South Africa;Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa;Institute for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa;Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK;Health GIS Centre, South Africa Medical Research Council, Durban, South Africa;Limpopo Provincial Malaria Control Programme, Polokwane, South Africa;Mpumalanga Provincial Malaria Control Programme, Nelspruit, South Africa;School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa;Tropical Epidemiology Group, Department of Infectious Diseases Epidemiology, London School of Hygiene and Tropical Medicine, London, UK;Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa;Tropical Epidemiology Group, Department of Infectious Diseases Epidemiology, London School of Hygiene and Tropical Medicine, London, UK;

关键词: Malaria;    Elimination;    Serology;    PfAMA-1;    PfMSP-1;    Transmission;    Heterogeneity;    Hotspot;    South Africa;   

DOI  :  10.1186/s12936-017-1701-7

 received in 2016-10-11, accepted in 2017-01-18,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundIt 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.MethodsFilter-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 blood-stage 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.ResultsThe 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).ConclusionsAlthough 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.

【 授权许可】

CC BY   
© The Author(s) 2017