Rotaviruses: diversity and zoonotic potential--a brief review.

Rotaviruses, a genus within the family Reoviridae, are among the most important etiological agents of severe diarrhoeal illness in humans and animals worldwide. Their genome, consisting of 11 segments of double-stranded RNA, is characterized by genetic variability including (i) point mutations, (ii) genomic reassortment, and (iii) genome rearrangements, thus leading to the considerable diversity of rotaviruses. Animal rotaviruses are regarded as a potential reservoir for genetic exchange with human rotaviruses. There is now increasing evidence that animal rotaviruses can infect humans, either by direct transmission of the virus or by contributing one or several genes to reassortants with essentially a human strain genetic background. As mixed infections are a prerequisite for reassortment events, cosurveillance of animal and human rotavirus strains will be vital to gain a better understanding of the relationships between cocirculating viruses, as well as assessing any relevant vaccination programs.