Novel gel-based and real-time PCR assays for the improved detection of African horse sickness virus

In order to improve, ensure and accelerate the diagnosis of African horse sickness, a highly devastating, transboundary animal disease listed by the World Animal Health Organisation, (OIE) three novel diagnostic PCR assays were developed and tested in this study. The reverse transcription-PCR (RT-PCR) tests were the following: (a) a conventional, gel-based RT-PCR, (b) a real-time PCR with SYBR-Green-named rRT-PCR SYBR-Green-, and (c) a real-time PCR rRT-PCR with TaqMan® probe (termed rRT-PCR TaqMan®). The same pair of primers-directed against African Horse Sickness Virus (AHSV) segment 5, encoding the non-structural protein NS1, is used in the three tests listed above. The three PCR assays detected similarly the nine AHSV serotypes from cultivated viral suspensions of different origins. The RT-PCR assays provided high sensitivity ranging from 0.1 to 1.2 TCID50/ml. The specificity was also high, considering that related viruses, such as Bluetongue virus, and other equine viruses, such as West Nile Virus, remained negative for RT-PCR amplification. The detection of AHSV virus can be completed within 2-3 h. These results indicate that the novel PCR methods described in this paper provide robust and versatile tools that allow rapid and highly specific, simultaneous detection of all AHSV serotypes.