Fine mapping of Ascaris lumbricoides, Trichuris trichiura and hookworm infections in sub-districts of Makenene in Centre Region of Cameroun

Preventive chemotherapy (PC) that remains the main control strategy recommended by the World Health Organization to achieve the elimination of soil-transmitted helminth (STH) infections as a public health problem must be strengthened by identifying the remaining transmission hot-spots for the deployment of appropriate control measures. This study was designed to assess the prevalence and infections intensities of soil-transmitted helminths and perform micro scale mapping in order to identify transmission hot-spots for targeted control operations. Stool samples were collected from 1775 children in ten primary schools of eight sub-districts of Makenene in Cameroon. Kato Katz technique was used to process and examine stool samples to detect the eggs of soil-transmitted nematodes. The prevalence of soil-transmitted helminth species as well as the infection intensities was compared. Data visualizations in forms of maps were made using Quantum geographic information system (QGIS) software. The overall prevalence of soil-transmitted helminth infections was 4.8% with a 95% confidence interval (CI) of 3.8–5.9%: 3.0% (95% CI 2.2–3.9) for Ascaris lumbricoides, 1.4% (95% CI 0.9–2.0) for Trichuris trichiura and 0.8% (95% CI 0.5–1.4) for hookworms. The prevalence of soil-transmitted helminth species differ significantly between schools and sub-districts. The intensity of infections was light (2.4%, 1.1% and 0.8%), moderate (0.4%, 0.1% and 0.1%) and heavy (0.2%, 0.2% and 0%) for A. lumbricoides, T. trichiura and hookworm respectively. The mean intensity of infections was 7255 EPG for A. lumbricoides, 2900 EPG for T. trichiura and 298 EPG for hookworm. Between schools, significant difference was recorded in the means of infection intensities of T. Trichiura and hookworms but not for A. lumbricoides. This difference was also significant for T. Trichiura when comparison were between sex. No significant difference were recorded when the comparison were between age. Fine mapping revealed that children harbouring heavy infections were clustered in the same sub-districts; highlighting the presence of high endemicity sub-districts and hot-spots for the transmission of different soil-transmitted helminth species. This study showed a diversity in the prevalence and transmission of different soil-transmitted helminth species. It also hightlighted the need for micro scale mapping to enable the localisation of high endemicity sub-districts and transmission hot-spot sites where targeted control operations must be deployed to achieve STH elimination.

Hemoglobin Level and Risk of Anemia in Soil-Transmitted Helminths Infections among Children: A Systematic Review and Meta-analysis

Introduction. Soil Transmitted Helminthiasis (STH) is a Neglected Tropical Disease with almost 25% world population infected. Children were vulnerable to infection with morbidities affecting growth. STH infection alters children nutritional status which potentially causing anemia. Meta-analysis relating STH infections to hemoglobin (Hb) level and risk of anemia in children is limited. Aim. To compare hemoglobin levels and risk of anemia in children infected and uninfected with STH. Methods. Meta-analysis conducted from journals obtained from Pubmed, ScienceDirect, WileyLibrary, Cochrane, EBSCO, Proquest, DOAJ, and GoogleScholar from 2011-2021. Full text cross sectional studies on children with relevant topic is included, while unclear, inaccessible, or post interventional studies were excluded. Articles were analyzed in Review Manager 5.4 in mean difference (MD) and odds ratio (OR) with Confidence Interval (CI) of 95%. Result. Out of 25,683 articles in literature search, 29 were eligible for systematic review and meta-analysis. STH infection significantly decreases hemoglobin level (MD -0.2g/dL; p=0.02) and increases risk of anemia (OR 1.83; p<0.00001). Species analysis presented parallel result on Trichuris trichiura (MD -0.31g/dL; p=0.001 and OR 1.66; p=0.009), Hookworm (MD -0.56g/dL; p=0.02 and OR 3.3; p<0.00001), and multiple infection (MD -0.25g/dL; p=0.03 and OR 4.49; p=0.005). Ascaris lumbricoides didn’t show significance on hemoglobin level but comparable for risk of anemia (MD -0.16g/dL; p=0.17 and OR 1.57; p=0.001). Discussion. All STH infections exhibits lower hemoglobin level and higher risk of anemia caused by lower nutrition absorption and occult bleeding in gastrointestinal tract. Hookworm and multiple infections has the highest risk of anemia. Proportion of anemia may vary in studies and influenced by sociodemographic characteristics, but higher proportions occur in STH infected. Conclusion. Children infected with STH has lower hemoglobin level and in risk of anemia compared to uninfected children, hence further study is still needed to be conducted. Keywords: Anemia, Children, Hemoglobin, Infection, Soil Transmitted Helminths