Cluster of acute hemorrhagic appendicitis among high school students in Wuhan, China

BACKGROUND: Features of a cluster of acute appendicitis that occurred among a high school student population in China were investigated. METHODS: Epidemiologic data, medical records, and histologic slides of resected appendices were examined. RESULTS: During a period between April 10, 1997, and June 11, 1997, 11 cases occurred in a high school, with 10 cases among 290 students enrolled at the time. From the end of the initial cluster until June, 2000, 20 additional cases were encountered. Female cases (6.5%) are more frequent than male cases (1.9%). There was a clustering pattern. Many patients had a history of mutual contact before the onset of symptoms. Pathologically, the resected appendices exhibited diffuse or focal hemorrhages in the lamina propria or within hyperplastic lymphoid follicles, and infiltration by eosinophils and by lymphocytes. Appendical tissues were examined using immunohistochemistry, but no etiologic agent was identified. CONCLUSIONS: This cluster of acute appendicitis represented a special kind of appendicitis, with features of an infectious disease in epidemiology.