Epidemiology of Schistosoma mansoni infection in Ituri Province, north-eastern Democratic Republic of the Congo

Abstract

Background Schistosomiasis, caused by Schistosoma mansoni, is of great significance to public health in sub–Saharan Africa. In the Democratic Republic of Congo (DRC), information on the burden of S. mansoni infection is scarce, which hinders the implementation of adequate control measures. We assessed the geographical distribution of S. mansoni infection across Ituri province in north-eastern DRC and determined the prevailing risk factors. Methods/Principal findings Two province–wide, community–based studies were conducted. In 2016, a geographical distribution study was carried out in 46 randomly selected villages across Ituri. In 2017, an in–depth study was conducted in 12 purposively–selected villages, across the province. Households were randomly selected, and members were enrolled. In 2016, one stool sample was collected per participant, while in 2017, several samples were collected per participant. S. mansoni eggs were detected using the Kato–Katz technique. In 2017, a point–of–care circulating cathodic S. mansoni antigen (POC–CCA) urine test was the second used diagnostic approach. Household and individual questionnaires were used to collect data on demographic, socioeconomic, environmental, behavioural and knowledge risk factors. Of the 2,131 participants in 2016, 40.0% were positive of S. mansoni infection. Infection prevalence in the villages ranged from 0 to 90.2%. Of the 707 participants in 2017, 73.1% were tested positive for S. mansoni. Prevalence ranged from 52.8 to 95.0% across the health districts visited. Infection prevalence increased from north to south and from west to east. Exposure to the waters of Lake Albert and the villages’ altitude above sea level were associated with the distribution. Infection prevalence and intensity peaked in the age groups between 10 and 29 years. Preschool children were highly infected (62.3%). Key risk factors were poor housing structure (odds ratio [OR] 2.1, 95% 95% confidence interval [CI] 1.02–4.35), close proximity to water bodies (OR 1.72, 95% CI 1.1–2.49), long-term residence in a community (OR 1.41, 95% CI 1.11–1.79), lack of latrine in the household (OR 2.00, 95% CI 1.11–3.60), and swimming (OR 2.53, 95% CI 1.20–5.32) and washing (OR 1.75, 95% CI 1.10–2.78) in local water bodies. Conclusions/Significance Our results show that S. mansoni is highly endemic and a major health concern in Ituri province, DRC. Infection prevalence and intensity, and the prevailing socioeconomic, environmental, and behavioural risk factors in Ituri reflect intense exposure and alarming transmission rates. A robust plan of action is urgently needed in the province.

Schistosoma Infection Burden and Risk Factors among School-Aged Children in a Rural Area of the Democratic Republic of the Congo

“…In contrast, other risk factors studied in our study, such as gender, swimming, washing clothes, washing dishes in the river, and the presence of taps and toilets in the households, did not show significant associations with Schistosoma infection. This finding contradicts previous studies conducted elsewhere [ 27 , 39 , 48 , 51 ]. However, as for our study, a recent study from Tanzania [ 52 ] also did not show an association between Schistosoma infection and water contact, although most participants had regular water contact.…”

“…This study found that age was an independent risk factor for Schistosoma infection. Participants aged 10–14 years were at a higher risk of infection than those aged less than 10 years, similar to the studies from the DRC [ 38 , 39 ] and elsewhere [ 46 , 47 , 48 , 49 ]. The main target risk group for Schistosoma infection consists of SAC of this age group due to their vulnerability to infection because of their behavior.…”

Burden and risk factors for Schistosoma mansoni infection among primary school children: A quantitative school-based cross-sectional survey in Busega district, Northern Tanzania

“…Our data also agree with the prevalence of S . mansoni observed in Ituri Province, in the north-eastern Democratic Republic of the Congo, which ranged between 52.8 to 95.0% in 2017 [ 33 ]. On the contrary, in Ethiopia, the observed prevalence was 11.2% among pre-school aged children, which is lower compared to the findings of the current study and highly variable among different sites in Ethiopia.…”

Evaluating Predictive Value ofSchistosoma mansoniPrevalence and Infection Intensity in School-Age Children in Estimating Community-Wide Prevalence in Siaya County, Western Kenya

“…These activities expose individuals to waters infested with the intermediate host (snail). School-age children (SAC), adolescents, women and young adults carry the greatest burden of morbidity and mortality associated with this infection (6)(7)(8). Equally, young children under 5 years are exposed especially in endemic regions.…”