THE OUTBREAK OF EQUINE INFLUENZA (H3N8) IN THE UNITED-KINGDOM IN 1989- DIAGNOSTIC USE OF AN ANTIGEN CAPTURE ELISA

In July 1989 influenza A/equine-2 (H3N8) was isolated from a nasophary ngeal swab taken from a non-thoroughbred horse exhibiting acute clinic al respiratory disease. This was the first isolation of equine influen za virus in the United Kingdom since 1981. Subsequent investigations o f acute respiratory disease in horses indicated that the infection was dispersed throughout the UK. However, unlike the previous epidemic of 1979, the first horses from which the virus was isolated had been vac cinated. This outbreak of influenza provided an opportunity to evaluat e an antigen capture ELISA, directed against the influenza virus nucle oprotein, as a rapid method for detecting virus in the nasopharyngeal secretions of naturally infected horses.