Dual infection due to simian G3--human reassortant and human G9 strains of rotavirus in a child and subsequent spread of serotype G9, leading to diarrhea among grandparents.

Cultivation of rotavirus from day 1 and 3 fecal specimens of a child yielded simian SA11-human reassortant, G3P[8] and AU32 like G9P[8] rotavirus strains, respectively. Diarrhea developed in the grandfather by sheer hospital visits, and in the grandmother, after wiping the vomit of the grandfather. AU32 like G9 strains were isolated from the grandparents also. Rotavirus specific IgM developed in all the three patients. A fourfold rise in G9 neutralizing antibodies was observed in the child and grandmother. The child's mother had asymptomatic rotavirus infection. The study highlights the potential of G9 serotype to spread from children to adults.