title: Use of real-time quantitative reverse transcription polymerase chain reaction for the detection of African horse sickness virus replication in Culicoides imicola.
abstract: Despite its important role as vector for African horse sickness virus (AHSV), very little  information is available on the dissemination of this virus in Culicoides (Avaritia) imicola Kieffer (Diptera: Ceratopogonidae). This study reports on the applicability of a real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) to detect AHSV in dissected  midges. A total of 96 midges were fed on AHSV-infected blood, after which one test group  was dissected into head/thorax and abdomen segments immediately after feeding and the  other only after 10 days of incubation. The majority of the midges (96%) ingested the virus  successfully and there was no significant difference between the virus concentration in the  heads/thoraxes and the abdomens immediately after feeding. After incubation, virus was  detected in 51% of the midges and it was confined to the abdomen in the majority of these.  The fact that virus was detected only in the heads/thoraxes of four Culicoides midges after  incubation suggests the presence of a mesenteronal escape barrier. Replication in the salivary  glands was not shown. An increase of the mean virus concentration in the abdomen after  incubation indicates localised viral replication. The real-time RT-qPCR is recommended for  further studies investigating the replication and dissemination of AHSV in Culicoides midges.
authors: Equine Research Centre, University of Pretoria. alan.guthrie@up.ac.za.
authors: Elisabeth G
authors: EG
authors: Scheffer
authors: Gert J
authors: GJ
authors: Venter
authors: Christopher
authors: C
authors: Joone
authors: Nikolaus
authors: N
authors: Osterrieder
authors: Alan J
authors: AJ
authors: Guthrie
mesh_terms: D034841:Abdominal Cavity; D000356:African Horse Sickness Virus / Q000235:genetics*; D000818:Animals; D002519:Ceratopogonidae / Q000821:virology*; D002683:Chironomidae / Q000821:virology*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary*; D014779:Virus Replication