A cross-sectional study of periportal fibrosis and Schistosoma mansoni infection among school-aged children in a hard-to-reach area of Madagascar

Background: A cross-sectional survey was performed to estimate the prevalence of periportal fibrosis in children based on ultrasound examination in the Marolambo district of the Atsinanana region of Madagascar. This is a remote area known to have a high prevalence of intestinal schistosomiasis. Methods: School-aged children (5-14 y) were selected from six villages for parasitological and sonographic examination. Circulating cathodic antigen (CCA) tests and Kato Katz (KK) stool microscopy were performed. Video-clips of liver views were recorded with a SonoSite iViz and interpreted in the UK by comparison with standardised images (WHO protocol). Results: The prevalence of schistosomiasis according to CCA testing was 97.8% (269/275) and 73.8% (203/275) by KK. Sonographic evidence of periportal fibrosis was observed in 11.3% (31/275). The youngest children with fibrosis were aged 6 y. Fibrosis was more common in older children (p=0.03) but was not associated with either infection intensity category (p=0.07) or gender (p=0.67). Conclusions: Findings of periportal fibrosis among children in these hard-to-reach villages suggests chronic Schistosoma mansoni infection from a very young age. This may reflect other similarly remote schistosomiasis-endemic areas and reinforces the need to investigate morbidity in neglected communities to understand the true extent of disease burden in endemic countries.