Status Report on African Horse Sickness

Almost six weeks ago the fact that cases of African Horse Sickness were detected in the Worcester and Robertson districts of the Western Cape Province was made public. To ensure that the public is kept informed about the status of this disease outbreak the present situation is outlined below.

The disease has been diagnosed on six properties in the Breede River valley on the border between the Worcester and Robertson districts. The diagnosis has been confirmed through virus isolation and identification procedures performed on samples taken from horses that died. The test result from a seventh property is still awaited. In total eighteen horses showed clinical signs of the disease and of these eight have died and two were put down.

Veterinary Services of the Western Cape Department of Agriculture is however confident that the disease outbreak has been effectively contained. This assessment is based on the following:

• The disease has not spread beyond a radius of about fifteen kilometres from the property where the first case was found and has remained within the Breede valley, where conditions are more suitable for the midges transmitting the disease.
• During the last two weeks the number of new cases has been less than the new cases detected during the two previous weeks.
• Weather conditions are changing rapidly. The onset of colder temperatures dramatically reduces midge population numbers, thus decreasing transmission of the disease-causing virus.

It however remains very important that the control measures, introduced at the start of the outbreak, must remain in place. The following control measures regarding the movement of horses, mules, donkeys and zebras are still applicable:

1. The arrangement for horses to "stand over" in the AHS control zone before entering the surveillance or free zones is still suspended. The widespread occurrence of the disease in other parts of the country does not allow for any relaxing of this restriction.
2. The following restrictions on the movement of horses, donkeys, mules and zebras, within or through the Worcester and Robertson districts, also remain in place:
   1. The movement of such animals between individual properties within the magisterial districts of Worcester and Robertson of the Western Cape Province may not take place.
   2. Horses from outside the surveillance zone may only move into the surveillance and free zones if they meet all the requirements specified in the protocol that has been in effect since 1997. Because the disease has become widespread in the rest of the country, few if any, horses are expected to meet these requirements at present. Their movement through the Worcester district will be on the following conditions:
      1. Movement permits must be obtained from the State Veterinarian in the area from where the animals are moving before horses are transported. The necessary notification of the movement must be done prior to departure.
      2. Vehicles transporting horses may only travel on the N1 highway through the Worcester district and may not turn off the N1 within Worcester magisterial district. The Worcester district stretches from Konstabel railway station (about halfway between Touwsrivier and Matjiesfontein) in the north up to the Rawsonville turnoff at the entrance to Du Toitskloof pass in the South. Along this route vehicles transporting horses may not stop for any protracted period of time and no horses may be up- or offloaded along this stretch of road.
      3. The transport of such animals along the N1 in the Worcester magisterial district may only take place during daylight between the hours of 08H00 and 17H00.
      4. Horseboxes or trailers must be sprayed with insecticides and insect repellents before animals are loaded for transit through the Worcester magisterial district.

Owners of horses are again reminded of the measures that can be taken to prevent their animals from contracting the disease:

• Vaccinate all horses according to the directions for AHS vaccine. It may be prudent to vaccinate younger foals, even if they have to be revaccinated within another few months.
• Where possible horses should be stabled from late afternoon to mid-morning.
• Keep horses out of low lying or marshy camps from late afternoon to mid-morning
• Apply insect repellents and insecticides suitable for horses, particularly where animals cannot be stabled

On behalf of the Western Cape Department of Agriculture, I want to express appreciation for the cooperation of all parties concerned in assisting with implementing effective control measures.

Enquiries:
Alie van Jaarsveld
Spokesperson
Ministry of Agriculture: Western Cape
Tel: 021 483 4930
Fax: 021 483 3890
Email: avjaarsv@pgwc.gov.za
Dr J P Kitching