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

BackgroundSchistosomiasis 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.MethodologyDuring 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.ResultsThe 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 Carriere. Houses with heavily-infected SAC were close to risky biotopes.ConclusionThis 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.Host-parasite interactio

Study of lymphoedema of non-filarial origin in the north west region of Cameroon: spatial distribution, profiling of cases and socio-economic aspects of podoconiosis

Background: Although podoconiosis is endemic in Cameroon, little is known about its epidemiology and spatial distribution. Methods: In this cross-sectional, population-based study, we enrolled all adults (≥15 years) residing in the districts of North-West Region of Cameroon for more than 10 or more years. Participants were interviewed, had physical examination. The study outcomes were prevalence estimates lymphoedema and podoconiosis. House-to-house screening was conducted by Community Health Implementers (CHIs). CHIs registered all individuals with lymphoedema and collected additional individual and household-related information. A panel of experts re-examined and validated all lymphoedema cases registered by CHIs. Results: Of the 439,781 individuals registered, 214,195 were adults (≥15 years old) and had lived in the districts of the Region for more than 10 years. A total of 2,143 lymphoedema cases, were identified by CHIs, giving a prevalence of lymphoedema 1.0% (95% confidence interval [CI]; 0.96-1.04) (2,143/214,195). After review by experts, podoconiosis prevalence in the study area was 0.48% (1,049/214,195) (95% CI; 0.46-0.52). The prevalence of podoconiosis varied by health district, from 0.16% in Oku to 1.92% in Bafut (p < 0.05). A total of 374 patients were recruited by stratified random sampling from the validated CHIs’ register to assess the clinical features and socio-economic aspects of the disease. Patients reportedly said to have first noticed swelling at an average age of 41.9 ± 19.1 (range: 6-90 years). Most patients (86.1%) complained of their legs suddenly becoming hot, red and painful. The majority (309, 96.5%) of the interviewees said they had worn shoes occasionally at some point in their life. The reportedly mean age at first shoe wearing was 14.2 ± 10.1 (± Standard Deviation), range (1-77 years). A high proportion (82.8%) of the participants wore shoes at the time of interview. Of those wearing shoes, only 67 (21.7%) were wearing protective shoes. Conclusion: This study provides insight into the geographical distribution and epidemiology of podoconiosis in the North West region of Cameroon, yet management is limited. Evidence-informed targeted interventions are needed to manage people with lymphoedem