RESUMO
<p><b>BACKGROUND</b>To survey a diarrhea outbreak in Guangan city and analyze the cause of the disease.</p><p><b>METHODS</b>The population enrolled in the surveillance came from four different settings and was randomly sampled. Stool specimens collected from diarrhea patients were tested ordinarily for enteric bacteria and further examined for viral pathogens with PAGE, ELISA and RT-PCR.</p><p><b>RESULTS</b>In total, 4,567 persons were surveyed, among them 942 had acute diarrhea (prevalence 20.63%). The incidence was higher in rural area (28.6%) than in urban area (19.6%) (chi-square =22.29, P less than 0.005) with a peak in May 10 through 25 four human caliciviruses were detected from stool specimens by ELISA and RT-PCR in specimens from 4 and 1 patients, respectively.</p><p><b>CONCLUSION</b>Human calicivirus probably was the cause of this diarrhea outbreak in Guangan city.</p>