title: Development of real-time RT-PCR for the detection of low concentrations of Rift Valley fever virus.
abstract: In recent years, Madagascar and the Comoros archipelago have been affected by epidemics of Rift Valley fever (RVF), however detection of Rift Valley fever virus (RVFV) in zebu, sheep and goats during the post epidemic periods was frequently unsuccessful. Thus, a highly sensitive real-time RT-PCR assay was developed for the detection of RVFV at low viral loads. A new RVF SYBR Green RT-PCR targeting the M segment was tested on serum from different RVF seronegative ruminant species collected from May 2010 to August 2011 in Madagascar and the Comoros archipelago and compared with a RVF specific quantitative real time RT-PCR technique, which is considered as the reference technique. The specificity was tested on a wide range of arboviruses or other viruses giving RVF similar clinical signs. A total of 38 out of 2756 serum samples tested positive with the new RT-PCR, whereas the reference technique only detected 5 out of the 2756. The described RT-PCR is an efficient diagnostic tool for the investigation of enzootic circulation of the RVF virus. It allows the detection of low viral RNA loads adapted for the investigations of reservoirs or specific epidemiological situations such as inter-epizootic periods.
authors.affiliation: CIRAD, UMR CMAEE, F-97490 Sainte-Clotilde, La Réunion, France; INRA, UMR 1309 CMAEE, F-34398 Montpellier, France; CRVOI, F-97490 Sainte Clotilde, La Réunion, France. Electronic address: mariannemaquart@yahoo.fr.
authors.forename: Marianne
authors.initials: M
authors.lastname: Maquart
authors.forename: Sarah
authors.initials: S
authors.lastname: Temmam
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Héraud
authors.forename: Isabelle
authors.initials: I
authors.lastname: Leparc-Goffart
authors.forename: Catherine
authors.initials: C
authors.lastname: Cêtre-Sossah
authors.forename: Koussay
authors.initials: K
authors.lastname: Dellagi
authors.forename: Eric
authors.initials: E
authors.lastname: Cardinale
authors.forename: Hervé
authors.initials: H
authors.lastname: Pascalis
mesh_terms: D000818:Animals; D017507:Comoros; D008270:Madagascar; D016133:Polymerase Chain Reaction / Q000379:methods; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D012295:Rift Valley Fever / Q000175:diagnosis / Q000662:veterinary* / Q000821:virology; D012296:Rift Valley fever virus / Q000302:isolation & purification*; D012418:Ruminants; D012680:Sensitivity and Specificity; D014730:Veterinary Medicine / Q000379:methods*; D014773:Virology / Q000379:methods*
keywords: Diagnostic tool; Inter-epidemic period; Rift Valley fever virus; Semi-nested RT-PCR