Control measures
All suspected cases of African horse sickness in equine animals must be investigated and appropriate measures in accordance with the Regulation (EU) 2016/429 ("Animal Health Law") and the rules for the prevention and control of certain diseases laid down in Commission Delegated Regulation (EU) 2020/687, including in particular its Annex III, have to be taken in case of confirmation.
Notification and reporting
In accordance with Commission Implementing Regulation (EU) 2020/2002 Member States shall notify the Commission and the other Member States of confirmation of any outbreak in their territory of African horse sickness. Member States shall also provide annual reports to the Commission and to the other Member States on the detection of African horse sickness.
The data shall be submitted electronically via the Animal Disease Information System (ADIS).
Description of the disease
African horse sickness (AHS) is a noncontagious viral disease affecting all species of equidae. It is caused by one or more of the nine different serotypes of an orbivirus of the family Reoviridae.
The disease is characterised by alterations in respiratory and circulatory functions. While the disease is usually fatal in horses, other equine species and their crossbreds may display only mild clinical signs. AHS does not affect humans, but may affect dogs.
Transmission - Because AHS is transmitted by at least two species of Culicoides midges, its occurrence is also affected by the seasonal changes in climatic and environmental conditions of the vector's habitat.
Occurrence - All serotypes of AHS virus occur in eastern and southern Africa; this distribution reflects that of zebra, but also of the African donkey, which cycle the virus asymptomatically. In West Africa AHS serotype 9, 7 and 2 are found.
Examples of the occasional outbreaks that have occurred outside sub-Saharan Africa are the pandemic in certain countries of the Middle East up to India and Turkey (1959-1961), the outbreaks in Spain (serotype 9, 1966) and the epidemic caused by serotype 4 in Spain (1987-1990), Portugal (1989) and Morocco (1989).
In 2019, outbreaks of AHS occurred in Thailand and subsequently in Malaysia. On this occasion, the Regional Representation of OIE has prepared a set of information documents and has recorded a number of events that may assist in preparing the required contingency plans.
Laboratory diagnosis of AHS, based on the identification of infectious virus, virus nucleic acid, viral antigens or specific antibodies, is of great importance, as the characteristic clinical signs and lesions can be confused with those of other diseases.
It is a listed disease according to the World Organisation for Animal Health (OIE). This means it is a transmissible disease that has the potential for very serious and rapid spread, irrespective of national borders, that is of serious socio-economic consequence and that is of major importance in the international trade in animals and germinal products.
During its 80th General Session, the World Assembly of Delegates of the OIE adopted Resolution No. 19 adding African horse sickness (AHS) to the list of diseases for which status is officially recognised by the OIE in accordance to the relevant provisions of the Terrestrial Code.
According to Resolution No. 19 adopted during the 82nd General Session in May 2014, all current EU Member States are included in the list of African Horse Sickness free Member Countries of OIE.
AHS Diagnostics
Relevant information can be found on the websites of EU reference laboratory for AHS and in the OIE Manual.