Detection of flaviviruses and orthobunyaviruses in mosquitoes in the Yucatan Peninsula of Mexico in 2008

Jose A. Farfan-Ale, Universidad Autonoma de Yucatan
Maria A. Lorono-Pino, Universidad Autonoma de Yucatan
Julian E. Garcia-Rejon, Universidad Autonoma de Yucatan
Victor Soto, Iowa State University
Karin S. Dorman, Iowa State University
Lyric Bartholomay, Iowa State University
Einat Hovav, Iowa State University
Bradley J. Blitvich, Iowa State University

This is a copy of an article published in the Vector Borne and Zoonotic Diseases© 2010 [copyright Mary Ann Liebert, Inc.]; Vector Borne and Zoonotic Diseases is available online at: http://online.liebertpub.com

Abstract

A total of 191,244 mosquitoes from 24 species were collected in the Yucatan Peninsula of Mexico from January to December 2008, and tested for the presence of cytopathic virus by virus isolation in Vero cells. Eighteen virus isolates were obtained, all of which were orthobunyaviruses. These were identified by reverse transcription-polymerase chain reaction (RT-PCR) and nucleotide sequencing as Cache Valley virus (n=17) and South River virus (n=1). A subset (n=20,124) of Culex quinquefasciatus collected throughout the year was further tested by RT-PCR using flavivirus-specific primers. Flavivirus RNA was present in this mosquito species year-round. The overall flavivirus minimal infection rate, expressed as the number of positive mosquito pools per 1000 mosquitoes tested, was 7.7 and the monthly flavivirus minimal infection rates ranged from 4.3 to 16.6. Approximately one-third of the RT-PCR products were sequenced and all corresponded to Culex flavivirus, a recently discovered insect-specific flavivirus.