Ultrasonographic detection and assessment of preclinical Oesophagostomum bifurcum - Induced colonic pathology

In northern Ghana and Togo, Oesophagostomum bifurcum infects an estimated 2 50,000 people, as determined by cultures of stool samples. The juvenile sta ges of the helminth develop within colonic wall nodules, causing Dapaong tu mor or multinodular disease, at the rate of 1 case per week at Nalerigu Hos pital in Ghana. Our aim was to discover whether suspected colonic-wall path ology is ultrasonographically visible in asymptomatic individuals living in the area where O. bifurcum is endemic. A total of 464 persons from 3 villa ges, ranging from highly infected to noninfected, were examined with ultras onography. Anechogenic colonic lesions with posterior wall enhancement were observed in 71 (54.2%) of 131 and 57 (24.5%) of 233 persons from the villa ges of endemicity, and no lesions were seen in persons from the village out side the area of endemicity. We describe the lesions noted in this study as nodules caused by O. bifurcum, on the basis of their association at a popu lation level with prevalence of larvae in stools, their expected ultrasonog raphic appearance and distribution (on the basis of our surgical experience with oesophagostomiasis), and the lack of a convincing differential diagno sis.