Background: A significant fraction of cases of diarrhea, a leading cause of childhood mortality worldwide, remain unexplained.

Objectives: To identify viruses in unexplained cases of diarrhea using an unbiased metagenomics approach.

Study design: Viral nucleic acids were enriched from the feces from 48 cases of unexplained diarrhea from Burkina Faso, sequenced, and compared against all known viral genomes.

Results: The full genome of a highly divergent astrovirus was sequenced in a sample co-infected with parechovirus 1. RT-PCR identified a single astrovirus infection in these 48 patients indicating a low prevalence. Human astrovirus-BF34 was most closely related to mamastrovirus species 8 and 9 also found in human with which it shared 62%, 74%, and 57% amino acid identities over its protease, RNA dependent RNA polymerase and capsid proteins, respectively.

Conclusions: Burkina Faso astrovirus is proposed as prototype for a novel species in the genus Mamastrovirus, here tentatively called Mamastrovirus 20, representing the fifth human astrovirus species.

Keywords: Astrovirus; Children; Diarrhea; Metagenomics; Species.

Astrovirus ; Children ; Diarrhea ; Metagenomics ; Species