bayou orthohantavirus bayou orthohantavirus bayou orthohantavirus (bayv) is a species of orthohantavirus first identified in 1993 in louisiana. and later confirmed by other investigators. in 1996, the marsh rice rat was identified as the natural reservoir of the virus, indicating the virus to be widespread throughout the southeastern united states. bayv infection causes hantavirus pulmonary syndrome (hps) and represents the second most common hantavirus in the united states behind the sin nombre orthohantavirus. bayou orthohantavirus virus classification (unranked): virus realm: riboviria kingdom: orthornavirae phylum: negarnaviricota class: ellioviricetes order: bunyavirales family: hantaviridae genus: orthohantavirus species: bayou orthohantavirus member viruses bayou virus louisiana catacamas virus synonyms bayou hantavirus bayou virus