The virus, which is carried by mosquitoes and birds, caused outbreaks of infection in North Africa and the Middle East in the 1950s and by the 1960s horses in Europe fell victim.
Pistesääsklaste ja lindude edasikantud viirus põhjustas 1950-ndatel haiguspuhanguid Põhja-Aafrikas ja Lähis-Idas ning 1960-ndatel nakatusid Euroopa hobused.