Serotype G9 may be the fifth most common human rotavirus serotype, after se
rotypes G1 to G4. In three cross-sectional studies of childhood diarrhea, w
e have detected serotype G9 rotaviruses for the first time in Libya, Kenya,
and Cuba. Serotype G9 constituted 27% of all rotaviruses identified, empha
sizing the reemergence of serotype G9 and suggesting that future human rota
virus vaccines will need to protect against disease caused by this serotype
.