DETECTION OF AFRICAN HORSE SICKNESS VIRUS BY REVERSE TRANSCRIPTION-PCR

Reverse transcription-PCR (RT-PCR) was used to detect African horse si ckness virus (AHSV), A single primer pair which amplified a 423-bp fra gment of the S8 gene which encodes the NS2 protein of AHSV was identif ied. Amplification of this fragment from all nine serotypes of AHSV wa s achieved with these primers. Between 10(1) and 10(2) copies of AHSV genomic double-stranded RNA could be detected by RT-PCR followed by ag arose gel electrophoresis and ethidium bromide staining. Application o f RT-PCR to blood samples from AHSV-infected horses resulted in earlie r detection of viremia than virus isolation did. Furthermore, viremia was detected by RT-PCR in blood samples from horses infected with an a virulent isolate of AHSV which were negative by virus isolation. AHSV was also detected by RT-PCR in spleen and lung samples from horses whi ch died of AHSV infection. These results indicate that RT-PCR is a rap id and sensitive method for the identification of horses infected vith AHSV.