Provided herein are sequences of the genomes and encoded proteins of new astrovirus species, and variants thereof. Also provided are methods of detecting the new astrovirus species and diagnosing astrovirus infection, methods of treating or preventing astrovirus infection, and methods for identifying anti-astrovirus compounds.Provided are two new astrovirus species named HMOAstV-A and HMOAstV-B, and both are distantly related to known astroviruses. Also provided is a new method of classifying astroviruses, where there are three groups of human astroviruses, including HAstV, AstV-MLB, and HMOAstV.
