Ongoing surveillance in Malaysia has yet to detect any further cases of African horse sickness in the country, raising hopes that the deadly disease hasn’t spread.
Five animals on one property were confirmed with the viral infection in the country’s initial report of the outbreak to the World Organisation for Animal Health (OIE), dated September 2.
The start of Malaysia’s outbreak — the first time the disease has been reported in the country — is officially put at August 6. Confirmation that the pathogen was African horse sickness virus came three weeks later, on August 27.
Its September 9 follow-up communication confirmed that all five horses affected by the disease, carried by biting midges, had been euthanized. The country’s latest report, dated September 16, shows that no new cases have been reported since the initial five.
Surveillance is said to be continuing inside and outside the containment zone set up to stop the spread of the disease.
Other measures employed so far include movement control within the country, screening, tracing measures, quarantine restrictions, and efforts to target the midges responsible for the spread of the disease.
Vaccination against the virus is not permitted in Malaysia.
The Malaysian cases follow the first-ever outbreak of the disease in nearby Thailand, first reported in February, which media reports have linked to the importation of zebras from Africa.
The five affected horses were in the state of Terengganu.
Malaysia shares a border with southern Thailand, and Terengganu is some 200km from that border. However, the centre of the Thailand outbreak is further afield, at least 1000km away.
Malaysia’s latest report says serotyping of the virus is still pending. The results will either largely confirm or rule out a link with the outbreak in Thailand. The African horse sickness virus comprises nine serotypes, with all cases in Thailand caused by serotype 1.
Thailand, in its latest report to the OIE, dated September 18, reports no new cases. The country, which has used vaccination as a key strategy to contain the disease, has not had a confirmed case since mid-June.
Thailand formally lists the cause of its outbreak as unknown or inconclusive at this stage.
African horse sickness is endemic in sub-Saharan Africa. Horses are considered the most susceptible, with nearly 90% dying if infected. It kills roughly half of infected mules and 10% of donkeys.