Epidemiology and Infection

African horse sickness in Portugal: a successful eradication programme

a1 Serviço Nacional Coudélico, Ministério da Agricultura, Av. Duque Ávila 32-2°, 1000 Lisboa, Portugal
a2 DETSA, Faculdade de Medicina Veterinária, Universidade Técnica, R. Gomes Freire, 1199 Lisboa codex, Portugal
a3 Direcção Geral de Veterinária, Ministério da Agricultura, Lg. Academia Nacional Belas Artes 2, 1200 Lisboa, Portugal
a4 Faculty of Computer Studies and Mathematics, University of the West of England, Coldharbour Lane, Bristol BS16 1QY, UK


African horse sickness (AHS) was diagnosed for the first time in southern Portugal in autumn 1989, following outbreaks in Spain. AHS virus presence was confirmed by virus isolation and serotyping. An eradication campaign with four sanitary zones was set up by Central Veterinary Services in close collaboration with private organizations. Vaccination began on 6 October. In February 1990, vaccination was extended to all Portuguese equines (170000 animals). There were 137 outbreaks on 104 farms: 206 of the equidae present died (16%) or were slaughtered (14%); 81·5% were horses, 10·7% were donkeys and 7·8% were mules. Clinical AHS occurred more frequently in horses than donkeys and mules. In the vaccinated population, 82 animals (62·2% horses and 37·8% mules and donkeys), died or were slaughtered due to suspected or confirmed AHS. One year after ending vaccination, December 1991, Portugal was declared free of AHS. Cost of eradication was US$1955513 (US$11·5/Portuguese equine).

(Accepted May 14 1999)

c1 Author for correspondence.