Rotavirus G and P types in children with acute diarrhea in Blantyre, Malawi, from 1997 to 1998: predominance of novel P[6]G8 strains.

One hundred rotavirus strains detected in children with acute diarrhea in Blantyre, Malawi, between July 1997 and January 1998 were characterized for G (VP7) and P (VP4) types by using multiplex, heminested, reverse transcription-polymerase chain reaction. A novel P[6]G8 rotavirus strain was identified in 42% of the specimens. The remaining strains comprised P[8]G3 (20%), P[6]G3 (10%), P[4]G8 (9%), P[6]G9 (3%), P[8]G4 (2%), P[6]G4 (2%), and P[4]G3 (1%). Rotavirus strains with mixed G or P types were identified in 2% of the specimens. Nine percent of the strains were nontypeable with the primers used. The P[6] genotype was identified in 57% of strains overall. This first description of serotype G8 rotavirus as a predominant strain has important implications for vaccine development in Africa. The finding of novel P/G combinations (P[6]G8 and P[4]G8) highlights the extraordinary diversity of rotaviruses in some countries.