Schistosoma haematobium infection morbidity, praziquantel effectiveness and reinfection rate among children and young adults in Gabon

Jean Claude Dejon-Agobé,Jeannot Fréjus Zinsou,Yabo Josiane Honkpehedji,Ayôla Akim Adegnika,Tamirat Gebru Woldearegai,Bayodé Roméo Adégbitè,Ance Mangaboula,Benjamin Mordmüller,Mirabeau Mbong Ngwese,Jean Ronald Edoa,Bertrand Lell,Martin Peter Grobusch

doi:10.1186/s13071-019-3836-6

Abstract

BackgroundSub-Saharan Africa carries most of the global burden of schistosomiasis. To optimize disease control and reduce morbidity, precise data are needed for control measures adapted to the local epidemiological situation. The objective of this study is to provide baseline information on schistosomiasis dynamics, including praziquantel (PZQ) treatment outcome in children and young adults living in the vicinity of Lambaréné, Gabon.MethodsEligible volunteers were included into a prospective longitudinal study. Urine filtration technique was used to detect eggs in urine for schistosomiasis diagnosis. Subjects were treated with 60 mg of PZQ once per month for three consecutive months, and the outcome was assessed by cure rate (CR) and egg reduction rate (ERR).ResultsA total of 328 volunteers were enrolled in the study with a mean (± SD) age of 12.2 ± 4.7 years-old. The female-to-male ratio was 0.99. Out of 258 participants in total, 45% had schistosomiasis during the survey and 43% presented with heavy infections. The incidences of haematuria and schistosomiasis were 0.11 and 0.17 person-years, respectively. After the first and third dose of PZQ, overall ERR of 93% and 95% were found, respectively; while the CR were 78% and 88%, respectively. Both ERR (100 vs 88%) and CR (90 vs 68%) were higher among females than males after the first dose. The CR increased for both groups after the third dose to 95% and 80%, respectively. After the first PZQ dose, ERR was higher for heavy compared to light infections (94 vs 89%), while the CR was higher for light than for heavy infections (87 vs 59%). After the third PZQ dose, ERR increased only for light infections to 99%, while CR increased to 98% and 75% for light and for heavy infections, respectively. The reinfection rate assessed at a mean of 44.6 weeks post-treatment was 25%.ConclusionsThe prevalence of schistosomiasis is moderate in communities living in the vicinity of Lambaréné, where a subpopulation with a high risk of reinfection bears most of the burden of the disease. To improve schistosomiasis control in this scenario, we suggest education of these high-risk groups to seek themselves a one-year PZQ treatment.Trial registration clinicaltrials.gov Identifier NCT 02769103. Registered 11 May 2016, retrospectively registered. https://clinicaltrials.gov/ct2/show/NCT02769013

Highlights

Sub-Saharan Africa carries most of the global burden of schistosomiasis
Zilé-PK villages is a set of villages located over 20 km along the national road south of Lambaréné where many human-freshwater body contact points considered as schistosomiasis foci exist (Fig. 1), leading to a considerable level of urogenital schistosomiasis prevalence
During that phase and before the first assessment of schistosomiasis status, 28 (8.5%) participants complained about visible haematuria which was confirmed by Combur test

Summary

Introduction

Sub-Saharan Africa carries most of the global burden of schistosomiasis. To optimize disease control and reduce morbidity, precise data are needed for control measures adapted to the local epidemiological situation. Schistosomiasis is considered the second most important parasitic disease after malaria [1]. It is a neglected tropical disease occurring frequently in sub-Saharan Africa where 85% of the worldwide infected population lives [2]. Parts of the population pursue daily activities such as household chores, bathing, and fishing in potentially infested water. In such areas where reinfection is common [3, 4], the WHO recommends implementation of targeted treatment through large-scale treatment to reduce the burden of disease [5], and to prevent morbidity in later life [6]. Administration of treatment at least once a year reduces early (visible haematuria, anemia) and late (portal hypertension, hepatic fibrosis, bladder cancer) schistosomiasis-associated morbidity [5, 7]

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