Prevalence, intensity, and risk factors of schistosomiasis and intestinal parasitic infections among primary school children in northern Uganda: Implications for public health interventions

Abstract

Abstract
Background
Schistosomiasis and intestinal parasitic infections remain major public health concerns in Uganda, particularly among school-aged children, where they contribute to anemia, malnutrition, and poor cognitive development. The Lango sub-region of Northern Uganda is endemic for Schistosoma mansoni, yet epidemiological data remain scarce. We conducted this study to determine the prevalence, intensity, and risk factors of infection to guide targeted control strategies.

Methodology/principal findings
We conducted a cross-sectional study between January and March 2023, involving 802 primary school children from randomly selected schools in Lira District, Lira City, and Kole District. Stool samples were examined using the Odongo-Aginya method to detect Schistosoma mansoni and intestinal parasites. Urine samples were screened using the Point-of-Care Circulating Cathodic Antigen (POC-CCA) test for Schistosoma mansoni and urine filtration for Schistosoma haematobium. Data on potential risk factors were collected via structured interviews and analyzed using logistic regression in SPSS version 25.0. The overall prevalence of schistosomiasis was 34.5% (S. mansoni), with light (11.6%), moderate (5.4%), and heavy (2.9%) infection intensities. Other intestinal parasites were detected in 20.3% of participants, including Ascaris lumbricoides (11.6%) and hookworms (6.4%). Children in P.3 (OR = 3.19, 95% CI: 1.67–6.08), P.4 (OR = 3.22, 95% CI: 1.71–6.08), and P.6 (OR = 2.62, 95% CI: 1.26–5.47) had significantly higher odds of S. mansoni infection compared to P.7, with Ayara pupils most at risk (OR = 35.05, 95% CI: 9.30–132.14). Elevated risks occurred in Apedi, Aberdyangotoo, and Bala schools, while pupils in Kole (OR = 0.46, 95% CI: 0.33–0.63) and Lira City (OR = 0.48, 95% CI: 0.20–1.14) had reduced odds. Low paternal education increased risk, whereas recent praziquantel treatment markedly reduced infection (OR = 0.10, p = 0.027).

Conclusions/significance
The study highlights the persistent and focal nature of schistosomiasis transmission in northern Uganda, shaped by school and district-level factors, socioeconomic disparities, and irregular MDA implementation. Strengthening and sustaining praziquantel distribution, expanding WASH infrastructure, and introducing targeted, school-focused interventions are essential to reduce reinfection and sustain control efforts. Addressing these factors is critical for Uganda to progress toward schistosomiasis elimination goals.

Author summary
Schistosomiasis and intestinal parasitic infections are significant public health challenges, especially in low-resource settings like Northern Uganda. These infections can lead to malnutrition, anemia, and impaired cognitive development, particularly in school-aged children. In this study, we investigated the prevalence, intensity, and risk factors for these infections among primary school children in the Lango sub-region of Northern Uganda. We examined stool and urine samples from over 800 children and found that more than one-third were infected with Schistosoma mansoni, the parasite responsible for intestinal schistosomiasis. Additionally, we identified other intestinal parasites, such as Ascaris lumbricoides (roundworms) and hookworms. Our findings show that school and district-level factors, socioeconomic disparities, low parental education levels, and irregular MDA implementation were linked to a higher risk of infection. However, children who had recently received treatment with praziquantel, the main drug used for schistosomiasis, were less likely to be infected. These results highlight the urgent need for expanded treatment programs, improved sanitation, and targeted health education efforts to reduce the burden of parasitic infections in Ugandan schoolchildren. By highlighting key risk factors, this study offers important evidence to inform policymakers and public health practitioners in developing targeted interventions, thereby supporting national and global efforts to accelerate schistosomiasis elimination.