[Investigation on serious diarrhea].

We made an etiologic and epidemiologic investigation on 92 cases of serious diarrhea patients treated at hospitals of different level in Longhai county in 1986. From 63 patients, pathogenic organisms were isolated with the case positive rate of 64.48%; There are totally 75 isolates with the strain positive rate of 81.52%, among which 50 strains were ETEC (66.67%). High incidence was in August and September, during which there were 77 cases accounting for 83.69% of total cases and pathogen isolation rate was the highest. The main pathogen was ETEC, most of them were ST-producing strains, whose toxigenic ability is stronger there was only 19.70% whose ratio of intestinal weight to body weight was less than 0.1000 and the rest 80.30% more than 0.1000 in baby mice test.