Associations between infection intensity categories and morbidity prevalence in school-age children are much stronger for Schistosoma haematobium than for S. mansoni

• Published in: PLoS neglected tropical diseases 2021-05, Vol.15 (5), p.e0009444-e0009444
• Main Authors: Wiegand, Ryan E, Secor, W Evan, Fleming, Fiona M, French, Michael D, King, Charles H, Deol, Arminder K, Montgomery, Susan P, Evans, Darin, Utzinger, Jürg, Vounatsou, Penelope, de Vlas, Sake J
• Format: Article
• Language: English
• Subjects: Adolescent; Africa South of the Sahara - epidemiology; Animals; Biology and Life Sciences; Bladder; Chemoprevention; Chemotherapy; Child; Data collection; Diameters; Diarrhea; Disease prevention; Elementary school students; Ethics; Female; Fibrosis; Health aspects; Humans; Infections; Laboratories; Liver - parasitology; Liver - pathology; Male; Medical ethics; Medicine and Health Sciences; Morbidity; Pain; Parasite Egg Count; Pediatric research; Portal vein; Protocols; Research ethics; Risk factors; Schistosoma haematobium; Schistosoma mansoni; Schistosomiasis; Schistosomiasis haematobia - pathology; Schistosomiasis mansoni - drug therapy; Schistosomiasis mansoni - pathology; Statistics; Tropical diseases; Ultrasonic imaging; Ultrasonic testing; Urinary Tract - parasitology; Urinary Tract - pathology; Urine; Urogenital system; Veins & arteries
• ISSN: 1935-2735; 1935-2727; 1935-2735
• DOI: 10.1371/journal.pntd.0009444

World Health Organization (WHO) guidelines for measuring global progress in schistosomiasis control classify individuals with Schistosoma spp. infections based on the concentration of excreted eggs. We assessed the associations between WHO infection intensity categories and morbidity prevalence for selected S. haematobium and S. mansoni morbidities in school-age children. A total of 22,488 children aged 6-15 years from monitoring and evaluation cohorts in Burkina Faso, Mali, Niger, Uganda, Tanzania, and Zambia from 2003-2008 were analyzed using Bayesian logistic regression. Models were utilized to evaluate associations between intensity categories and the prevalence of any urinary bladder lesion, any upper urinary tract lesion, microhematuria, and pain while urinating (for S. haematobium) and irregular hepatic ultrasound image pattern (C-F), enlarged portal vein, laboratory-confirmed diarrhea, and self-reported diarrhea (for S. mansoni) across participants with infection and morbidity data. S. haematobium infection intensity categories possessed consistent morbidity prevalence across surveys for multiple morbidities and participants with light infections had elevated morbidity levels, compared to negative participants. Conversely, S. mansoni infection intensity categories lacked association with prevalence of the morbidity measures assessed. Current status infection intensity categories for S. haematobium were associated with morbidity levels in school-age children, suggesting urogenital schistosomiasis morbidity can be predicted by an individual's intensity category. Conversely, S. mansoni infection intensity categories were not consistently indicative of childhood morbidity at baseline or during the first two years of a preventive chemotherapy control program.