We report data regarding the molecular epidemiology of human astrovirus (HAstV) infections among children in Madagascar. In a 13-month study, 5 HAstV isolates were detected in fecal samples from 237 children (2.1%) by reverse transcription-PCR. Phylogenetic analysis showed the cocirculation of usual and unusual HAstVs.
Of 237 children with acute gastroenteritis in Antananarivo, Madagascar, during May 2004-May 2005, 14 ( 6%) were infected with norovirus. Seasonality (November-December peak) was detected. Reverse transcription-PCR identified GII as the most common genogroup. GIs belonged to GI.1, GI.3, and GI.4. Noroviruses in Madagascar show extensive genetic diversity.