Incidence and genetic diversity of group C rotavirus among adults

Fecal samples from a 1-year prospective study were investigated to establis h the role of group C rotavirus infections in acute diarrhea in Swedish adu lts (>15 years old). Rotaviruses were found in samples from 3% of the patie nts, and, in 35% of these, group C rotavirus was detected. Clinical symptom s of group C rotavirus infection were generally milder than those of group A rotavirus infection. Gene 8 (vp7) from 12 group C isolates, including str ains from the prospective study, a military outbreak, and a sporadic case, was sequenced. The gene was found to be extremely conserved, with identitie s of 99.1%-100% at the amino acid level. This study has systematically inve stigated the prevalence and genetic diversity of group C rotavirus in adult s. The data confirm the extreme sequence conservation within human group C rotavirus strains and suggest that symptomatic group C rotavirus infections occur more frequently in adults than has been previously recognized.