Consistency of Fecal Egg Output in Patients with Opisthochiasis Viverrini

Abstract

Counts of Opisthorchis eggs in two samples of feces arbitrarily taken 0–21 days apart from each of 209 patients from northeastern Thailand were carried out by Stoll's dilution technique. Based on the number of eggs/mg feces, each patient was classified as uninfected, lightly infected ( 10–50/mg), or very heavily infected (> 50/mg). The intensity of infection for each of the 209 individuals as shown by first and second counts was compared. Of the 209 individuals, 150 (71.8%) remained within the same egg excretion category, with all but five (2.4%) of the remainder being in an adjacent category. Statistical analysis showed no effect of variation in interval between stool counts on the accuracy or consistency of replicate counts.