Prevalence of rotavirus antibody among isolated South American Indian communities.

Rotavirus antibody was detected by enzyme-linked immunosorbent assay (ELISA) in 711 (54.7%) of 1,299 serum samples collected from Indians belonging to 13 relatively isolated communities in the Amazon region. The Parakanãs Novos Indians showed prevalences of immunity of 17.9% and 10.7% by ELISA and the indirect fluorescent antibody technique, respectively. The remaining tribes, with the exception of the Yanomamis, Tucanos, and Xicrins, had percentages of positivity greater than 50% by at least one technique; among both the Kubenkrankreins and the Oyampis, all individuals over 20 years of age possessed antibody. High percentages of rotavirus positivity were observed among the Apalais, ranging from 56.0% (age group 31-40 years) to 74.0% (age group 0-5 years). In the Kubenkrankreins, Maiogongs, and Tucanos, the prevalences of rotavirus antibody regularly increased with age. ELISA and the indirect fluorescent antibody technique agreed in 72.5% of the specimens, but the former test yielded more positives than the latter.