Prevalence of intestinal schistosomiasis in pre-school aged children: a pilot survey in Marolambo District, Madagascar

Caitlin Sheehy,Alice Reid,Louis Andrianjaka,Robbie Kornitschky,Antsa Andrianiaina,J Russell Stothard,Gina U Raderalazasoa,Amaya L Bustinduy,Stephen A Spencer,Emmanuel H Andriamasy,Jenny S Emmanoela,Hannah J Russell,James M Stj Penney,Tahiry N Ranaivoson,Heather Lawson,Graham Dodge

doi:10.1186/s40249-021-00871-y

Abstract

School-aged children (SAC) have a considerable burden of intestinal schistosomiasis in Madagascar yet its burden in pre-school aged children (PSAC) is currently overlooked. To assess the at-risk status of PSAC, we undertook a pilot epidemiological survey in June 2019 examining children (n = 89), aged 2–4-years of balanced gender, in six remote villages in Marolambo District, Madagascar. Diagnosis included use of urine-circulating cathodic antigen (CCA) dipsticks and coproscopy of stool with duplicate Kato-Katz (K-K) thick smears. Prevalence of intestinal schistosomiasis by urine-CCA was 67.4% (95% confidence interval [CI]: 56.5–77.2%) and 35.0% (95% CI: 24.7–46.5%) by K-K. The relationship between faecal eggs per gram (epg) and urine-CCA G-scores (G1 to G10) was assessed by linear regression modelling, finding for every increment in G-score, epg increased by 20.4 (6.50–34.4, P = 0.006). Observed proportions of faecal epg intensities were light (78.6%), moderate (17.9%) and heavy (3.6%). Soil-transmitted helminthiasis was noted, prevalence of ascariasis was 18.8% and trichuriasis was 33.8% (hookworm was not reported). Co-infection of intestinal schistosomiasis and soil-transmitted helminthiasis occurred in 36.3% of PSAC. These results provide solid evidence highlighting the overlooked burden of intestinal schistosomiasis in PSAC, and they also offer technical guidance for better surveillance data for the Madagascan national control programme.

Highlights

IntroductionSchistosomiasis remains to be a significant global public health problem, in sub-Saharan Africa and Madagascar [1]
Despite substantial control efforts, schistosomiasis remains to be a significant global public health problem, in sub-Saharan Africa and Madagascar [1]
Recent epidemiological studies of school-aged children (SAC) have documented very high burdens of infection and disease [3]. Both Schistosoma haematobium and Schistosoma mansoni exist on Madagascar; S. haematobium causes urogenital schistosomiasis and is present in northern and western districts; S. mansoni, which causes intestinal schistosomiasis, is present in eastern and southern districts; there are areas of co-endemicity in four regions in north-central and south-western parts of the country [2]

Summary

Introduction

Schistosomiasis remains to be a significant global public health problem, in sub-Saharan Africa and Madagascar [1]. In Madagascar, 107/114 districts are endemic for schistosomiasis, with the national control programme offering praziquantel to school-aged children (SAC), aged 5-15, only through school-based mass drug administration (MDA) [2]. Recent epidemiological studies of SAC have documented very high burdens of infection and disease [3]. Both Schistosoma haematobium and Schistosoma mansoni exist on Madagascar; S. haematobium causes urogenital schistosomiasis and is present in northern and western districts; S. mansoni, which causes intestinal schistosomiasis, is present in eastern and southern districts; there are areas of co-endemicity in four regions in north-central and south-western parts of the country [2]. Schistosoma mansoni infection typically presents with bloody diarrhoea, abdominal pain and bloating

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