Sonographical diagnosis and assessment of Oesophagostomum bifurcum induced colonic pathology: intra- and inter-observer variation studies

To estimate the reliability of ultrasound for the detection of colonic wall pathology induced by the intestinal parasitic helminth O. bifurcum, three studies to assess the intraand inter-observer variation of the technique were performed. In the endemic area of northern Ghana, 181 people from a low prevalence village and 62 people from a high prevalence village were examined twice by the same observer, and 111 people were independently investigated by two observers in a moderately endemic village. Kappa for the prevalence observations in the three studies were 0.82, 0.87 and 0.81 respectively, and kappa for the intensity observations were 0.66, 0.63 and 0.71 respectively. The upper 95% confidence intervals of the average absolute difference in nodule size measurements in studies 1 and 3 were 3.6 mm and 4.5 mm. Ultrasound has a promising future for the diagnosis and management of O. bifurcum colonic pathology.