Africian horse sickness (AHS) is a noncontagious, infectious arthropod- borne virus disease of equines. Its effects can be devastating with mortality rates over 90%. In 1987 the virus gained access to Europe (Iberian Peninsula) and persisted for at least 4 years before spreading into Morocco
This project was designed to counter the threat to the European livestock industry.
ELISAs for the detection of AHS virus specific antigens and antibodies were developed, validated and supplied to the European and FAO/OIE AHS Reference Centres where their use is now routine. Protocols and reagents are available for world-wide delivery. A further ELISA was also developed and permits differentiation between animals infected naturally and those vaccinated with an inactivated vaccine.
New purification methods have enabled significant advances in our knowledge of the structural components of the virus and the processes of infection and virogenesis in vector insects.
Work has also shown that viruses can survive for extended periods at low temperature (less than 10 C) in vectors whose life span is extended at these temperatures. This situation could provide an overwintering mechanism for Iberia and beyond. Mathematical models dealing with aspects of AHS epidemiology have been developed.
Over 60 scientific papers have been published and an international meeting arranged for 1997.
The project will comprise two main approaches. The first will involve the development and provision of novel, improved tests for the diagnosis of AHS. It is intended that these tests will be quick, reliable, specific, highly sensitive and able to detect "early" cases of disease. It is expected that extensive and detailed information on the basic properties of AHS virus itself, its structural components and its relationship to other Orbivirus groups will also be derived during the course of this work. The second approach will provide detailed information on the ulicoides vectors of AHS virus in Iberia in terms of the species involved, their distribution, population densities, survival rates, seasonal incidence and vector capacity in relation to the pre vailing climatic conditions. The information collected may be used to provide the greater part of a data base for the development of models designed to assess risk from AHS as a function of climatic conditions.
The results provided by this project will find wider application than for AHS alone since they will be applicable to the identification and control of other even more damaging Orbivirus diseases of cattle, deer and sheep (bluetongue, epizootic haemorrhagic disease) which threaten the livestock of the Community.
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