A cross-sectional study of periportal fibrosis and Schistosoma mansoni infection amongst 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 years) 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 i- Viz 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 six years old. Fibrosis was more common in older children (p=0.03) but was not associated with infection intensity category(p= 0.07) or gender (p=0.67). Conclusions: Findings of periportal fibrosis amongst 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 in order to understand the true extent of disease burden in endemic countries