An outbreak of rotavirus diarrhea among a nonimmune, isolated South American Indian Community

Abstract

During July-August 1977, an outbreak of acute diarrhea occurred in an unusually isolated population, lhe Tiriyó Indians, who live in lhe north of Pará, Brazil, near lhe border with Surinam. Diarrhea was reported by 157 (70%) of lhe 224 Indians living in lhe village during lhe epidemic. There was one fatal case in a one year old child. Rotavirus was detected by electron microscopy in one fecal specimen collected from an acute case of diarrhea. Seroconversions were noted in 127 out of 168 (75.6%) paired serum samples tested for rotavirus antibody by counter-immunoelectrophoresis. With immunofluorescence based neutralization tests, rotavirus serotype 1 (Birmingham) was shown to be associated with lhe outbreak. The infection also boosted type 3 antibodies but this was most apparent in persons with pre-existing type 3 titers and lhe boost was not as great as with type 1. Ali age groups were affected. The proportion symptomatic was greatest in young children.