No new cases of African horse disease in Malaysia have been found

23 Sep 2020

Any more reports of African horse sickness in the nation are yet to be identified by ongoing surveillance in Malaysia, boosting expectations that the deadly illness has not spread. 

In the country's initial epidemic notification to the World Organization for Animal Health (OIE), dated 2 September, five animals on one property were found to have a viral infection. 

The start of Malaysia's epidemic is officially scheduled on August 6, the first time the disease has been recorded in the region. Three weeks later, on August 27, evidence that the pathogen was the African horse sickness virus arrived. 

Its follow-up correspondence from September 9 reported that all five horses infected by the disease, borne by biting midges, were euthanized. The most recent report from the nation, dated 16 September, indicates that no new cases have been identified after the initial five. 

It is said that monitoring continues within and beyond the containment zone set up to avoid the epidemic from spreading. 

Other steps that have been utilized to date include monitoring of travel within the region, screening, tracking initiatives, limitations on quarantine, and initiatives to eliminate the midges responsible for the spread of the disease. 

In Malaysia, a vaccine against the virus is not allowed. 

Cases in Malaysia follow the first outbreak of the disease in neighboring Thailand, first recorded in February and related to the importation of zebras from Africa in media accounts. 

The five horses that were infected were in Terengganu province. 

The boundary with southern Thailand is shared by Malaysia, and Terengganu is some 200 km from that area. The origin of the epidemic in Thailand, however, is farther afield, at least 1000 km north. 

Malaysia's most current study notes that the virus' serotyping is still pending. The findings could either greatly validate or rule out a link with the outbreak in Thailand.

There are nine serotypes of the African horse sickness virus, with all cases triggered by serotype 1 in Thailand. 

In its latest submission to the OIE, dated 18 September, Thailand registered no new incidents. As of mid-June, a country that has employed vaccination as a primary disease containment technique has not seen a reported event. 

At this point, Thailand officially lists the cause of its outbreak as uncertain or inconclusive. 

In sub-Saharan Africa, African horse sickness is prevalent. Horses, with about 90 percent dying if contaminated, are among the most vulnerable. It destroys approximately half the mules that are contaminated and 10% of the donkeys.