A genetic analysis of the Oropouche virus species and identification of a novel M segment sequence.

Oropouche virus (OROV) is a public health threat in South America, and in particular in northern Brazil, causing frequent outbreaks of febrile illness. Using a combination of deep sequencing and Sanger sequencing approaches, we determined the complete genome sequences of eight clinical isolates that were obtained from patient sera during an Oropouche fever outbreak in Amapa state, northern Brazil, in 2009. We also report the complete genome sequences of two OROV reassortants isolatd from two marmosets in Minas Gerais state, south-east Brazil, in 201 2 that contained a novel M genome segment. Interestingly, all 10 isolates possessed a 947 nt S segment that lacked 11 residues in the S-segment 3' UTR compared with the recently redetermined Brazilian prototype OROV strain BeAn19991. OROV maybe circulating more widely in Brazil and in the non-human primate population than previously appreciated, and the identification of yet another reassortant highlights the importance of bunyavirus surveillance in South America.