Fine-scale mapping of Schistosoma mansoni infections and infection intensities in sub-districts of Makenene in the Centre region of Cameroon

PLoS Negl Trop Dis. 2022 Oct 13;16(10):e0010852. doi: 10.1371/journal.pntd.0010852. eCollection 2022 Oct.

Abstract

Background: Schistosomiasis control relies mainly on mass drug administration of Praziquantel (PZQ) to school aged children (SAC). Although precision mapping has recently guided decision making, the sub-districts and the epidemiological differences existing between bio-ecological settings in which infected children come from were not taken into consideration. This study was designed to fill this gap by using POC-CCA and KK to comparatively determine the prevalence and infection intensities of Schistosoma mansoni (S. mansoni) and to perform fine-scale mapping of S. mansoni infections and its infection intensities with the overarching goal of identifying sub-districts presenting high transmission risk where control operations must be boosted to achieve schistosomiasis elimination.

Methodology: During a cross- sectional study conducted in Makenene, 1773 stool and 2253 urine samples were collected from SAC of ten primary schools. S. mansoni infections were identified using the point of care circulating cathodic antigen (POC-CCA) and Kato-Katz (KK) test respectively on urine and stool samples. Geographical coordinates of houses of infected SAC were recorded using a global position system device. Schistosome infections and infection intensities were map using QGIS software.

Results: The prevalence of S. mansoni inferred from POC-CCA and KK were 51.3% and 7.3% respectively. Most infected SAC and those bearing heavy infections intensities were clustered in sub-districts of Baloua, Mock-sud and Carrière. Houses with heavily-infected SAC were close to risky biotopes.

Conclusion: This study confirms the low sensitivity of KK test compared to POC-CCA to accurately identify children with schistosome infection and bearing different schistosome burden. Fine-scale mapping of schistosome infections and infection intensities enabled to identify high transmission sub-districts where control measures must be boosted to reach schistosomiasis elimination.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Antigens, Helminth
  • Cameroon / epidemiology
  • Child
  • Feces
  • Humans
  • Praziquantel / therapeutic use
  • Prevalence
  • Schistosoma mansoni
  • Schistosomatidae*
  • Schistosomiasis mansoni* / prevention & control
  • Schistosomiasis*
  • Sensitivity and Specificity

Substances

  • Praziquantel
  • Antigens, Helminth

Grants and funding

o This work was supported throughby H3Africa [H3A-18-004] to GS. The Human Heredity and Health in Africa (H3Africa) is a programme of the Alliance for Accelerating Excellence in Science in Africa (AESA) platform. AESA is a funding, agenda-setting and programme management initiative of the African Academy of Sciences (AAS), the African Union Development Agency (AUDA-NEPAD), founding and funding global partners, and through a resolution of the summit of African Union Heads of Governments. H3Africa is supported by the National Institute of Health (NIH), Wellcome Trust, and African Society of Human Genetics (AfSHG). This work was also supported by a grant from the United States Agency for International Development (USAID) and UK aid from the British people (UK aid) to EMM through the Coalition for Operational Research on Neglected Tropical Diseases (COR-NTD) and administered by the African Research Network for Neglected Tropical Diseases (ARNTD).; grant number SGPIII/0210/388. EMM was funded by H3A/18/004 and ARNTD. AAZT and GS were funded by H3A/18/004. CNK was funded by MTN/OCEAC project; HMW, RJAT, EYT and LETM by the University of Dschang; MCP by the Leiden University Medical Center, MCTM and FN by the University of Yaounde 1. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.