Detection of porcine rotavirus type G9 and of a mixture of types G1 and G5 associated with Wa-like VP4 specificity: evidence for natural human-porcine genetic reassortment.

Rotavirus type G5 is a primarily porcine pathogen that has caused frequent and widespread diarrhea in children in Brazil and in piglets elsewhere. Initial results on the rotavirus types circulating in diarrheic piglets in Brazil disclosed a high diversity of strains with distinct G types including G1, G4, G5, and G9 and the novelty of P[8], the predominant human P specificity type. Those results add strong evidence for the emergence of new strains through natural reassortment between rotaviruses of human and porcine origins.