Identification of bluetongue virus and epizootic hemorrhagic disease virus serotypes in French Guiana in 2011 and 2012

- High prevalence of Orbivirus in French Guiana.
- First isolation of BTV-1 and 2 in South America.
- First identification of EHDV-1 and 6 in South America.
- Risk of introduction of new serotypes with live animal trade.
- Risk of emergence of reassortant viruses with a virulent phenotype.

In French Guiana, the sero- and viro-prevalence of Bluetongue virus (BTV) is high but the circulating serotypes remain unknown. No data are available regarding the prevalence of Epizootic hemorrhagic disease (EHD). This study was conducted to assess the prevalence and to identify the circulating serotypes of these two Orbiviruses in this region (BTV and EHDV). Blood samples were collected in main livestock areas, from 122 young cattle between June and August 2011, to perform virological (PCR and viral isolation) and serological (ELISA) analyses. Moreover, samples from sheep and goat showing BTV-like clinical signs and from newly imported animals were analyzed using the same assays. Results confirmed an important viral circulation, with viro- and seroprevalence of 85% and 84% and 60% and 40% for BTV and EHDV, respectively. Ten Orbivirus serotypes were identified (BTV-1, 2, 6, 10, 12, 13, 17 and 24, EHDV-1 and 6). The circulation of many serotypes in intertropical America and in the Caribbean region underlines the need to establish measures to monitor and control animal movements.