Phylogenetic Relationships Among Orthobunyaviruses Isolated from Mosquitoes Captured in Peru

The Orthobunyavirus genus of the family Bunyaviridae is comprised of over 220 extremely diverse viral species. Members of this genus are often associated with acute febrile illness in animals and humans. As part of a longterm study of the ecology of arboviruses in the Amazon basin of Peru, we have isolated over 60 orthobunyaviruses from mosquitoes. The identification of many of these isolates by fluorescent antibody assay has been confounded by the lack of specificity of many available reagents. Therefore, we initiated genetic characterization, based on the S and M genomic segments, of selected viral isolates. Based on comparisons of the nucleotide sequences of the nucleocapsid gene, Wyeomyia, a virus in the Bunyamwera group, was the most related Orthobunyavirus species. Within the nonstructural S (NSs) open reading frame of the S segment, we found four conserved stop codons for the Peruvian isolates. Detailed comparisons of Bunyamwera, Simbu viruses, Group C viruses, and California viruses revealed all f...