Morbidity and mortality due to Ascaris-induced intestinal obstruction

We examined epidemiological aspects of Ascaris-induced intestinal obstruction (AI-IO) through analysis of published reports on the subject. In 9 studies of > or = 100 patients admitted to hospital due to ascariasis, intestinal obstruction was the single most common complication and accounted for 38-87.5% of all complications (weighted mean 72%). The proportion of intestinal obstruction caused by ascariasis was identified in 14 studies from 7 countries with varying degrees of endemic ascariasis. Using relevant data on the duration of the study, the number of beds in the reporting hospital, and the number of hospital beds/1000 population in the area, the number of cases of AI-IO/year/1000 population was estimated from 11 studies. Both the proportion of AI-IO (range 0-0.71) and the number of cases of AI-IO/year/1000 population (range 0-0.25) were significantly related, in a non-linear manner, to the local prevalence of ascariasis (range 0.01-0.92). In 12 studies of > or = 30 patients with AI-IO, the case fatality rates ranged from 0 to 8.6% (weighted mean 5.7%). The mean age of patients with AI-IO was < or = 5 years in 6 of 7 studies in which age was specified.