Human P[6] Rotaviruses From Sub-Saharan Africa and Southeast Asia Are Closely Related to Those of Human P[4] and P[8] Rotaviruses Circulating Worldwide.

BACKGROUND P[6] rotaviruses have been circulating with a high prevalence in African and, to a more limited extent, Asian countries, but they have not been highly prevalent in other parts of the world. METHODS To investigate the genomic relationship between African and Asian human P[6] rotaviruses and P[4] and P[8] rotaviruses circulating worldwide, we sequenced 39 P[6] strains, collected in Ghana, Mali, Kenya and Bangladesh, providing the largest data set of P[6] rotavirus genomes isolated in low-income countries or anywhere else in the world that has been published thus far. RESULTS Overall, the data indicate that the genetic backbone of human P[6] strains from the low-income countries are similar to those of P[4] or P[8] strains circulating worldwide. CONCLUSIONS The observation that gene segment 4 is the main differentiator between human P[6] and non-P[6] strains suggests that the VP4 spike protein is most likely one of the main reasons preventing the rapid spread of P[6] strains to the rest of the world despite multiple introductions. These observations reinforce previous findings about the receptor specificity of P[6] rotavirus strains.