Natural progression of Oesophagostomum bifurcum pathology and infection ina rural community of northern Ghana

An estimated 250 000 people in northern Ghana and Togo are infected with th e intestinal helminth parasite Oesophagostomum bifurcum, as detected by sto ol cultures. Clinical disease caused by O. bifurcum is responsible for abou t 50 cases per year at the region's central hospital, and presents as painf ul abdominal masses: inflammatory colonic nodules containing live juvenile stages of the helminth. In individuals living in villages highly endemic wi th O. bifurcum infection, colonic pathology visible by ultrasound is also h ighly prevalent. These nodules also contain O. bifurcum juvenile worms but are apparently asymptomatic. Thus, O. bifurcum infection and asymptomatic c olonic pathology are highly prevalent within this area, but clinical diseas e is relatively uncommon. The natural evolution and regression of the colon ic pathology in an endemic community in northern Ghana and its distribution within the population is described. Of the 299 individuals in the study gr oup, 28% had colonic pathology at recruitment in the late-rainy season, whi ch decreased with a half-life of 3-4 months during the dry season. Of those negative at recruitment, 28% developed nodules during the year, the majori ty appearing at the end of the subsequent rainy season. Children tended to have a higher prevalence and intensity of ultrasound-visible pathology comp ared to adults. Almost half (49%) of the study group had colonic nodules at least once during the year, and 2% of these individuals presented with cli nical disease to the local hospital during the mid-rainy season.