Poor hygiene the likely cause of Western Cape swine fever outbreak 

Farmers in Mfuleni in the Western Cape are battling a debilitating outbreak of African swine fever (ASF) which has forced them quarantine until the virus clears. 

According to Boland chief state veterinarian, Dr Gary Buhrmann, ASF is endemic north of South Africa, above what is known as the red line area. 

This includes most of Limpopo and parts of Mpumalanga and the North West. So far, 100 pigs have been culled in the North West.

Burhmann suspects the disease may have been brought into the Western Cape from the Eastern Cape, due to the same serotype of the virus diagnosed in the Western Cape being found in an earlier outbreak. 

ALSO READ: Speculators blamed for recent African swine fever outbreak in Potchefstroom

“We know there are a large number of Eastern Cape residents living in this area and it is quite possible that they either brought infected piglets or pork products back on their return from the Eastern Cape after the Christmas break, as reports seem to indicate the deaths started at least two months ago.” 

Burhmann said the last ASF outbreak in the Western Cape happened in the 1930s and the outbreak was due to poor biosecurity practices. 

ASF is spread through warthogs who are carriers of the virus, but resistant to its effects. 

The warthogs have ticks on them that carry the virus, but when warthogs come into contact with domestic pigs they are infected with the virus. 

Warthogs come into contact with domestic pigs via speculators at auctions and people selling infected pigs or warthogs to game farms.

“The reason we are the last to be infected is probably because we are the furthest away from the original source, which was in Limpopo province.”

Outbreaks usually result in “mass mortality within a few days”, due to the virus’s haemorrhagic-like syndrome. 

In acute cases, Burhmann said pigs die within three to five days, with the possibility of 90% to 100% mortality rates. 

“However, in our case it appears we have the more subacute form of the disease and the mortality in the infected herds seems to be only about 20% and only affects 4% of the whole Mfuleni pig population.” 

Pigs can remain infective for up to three weeks. ASF can survive in moist, cool environments for several months, Burhmann warned. 

As such, no new pigs can be introduced to previously infected farms for at least three months. These farms also have to be depopulated, cleaned and disinfected to prevent a recurrence.

Due to its viral nature there is no treatment or vaccine for ASF. This means infected pigs have to be killed. 

However, Buhrmann said the Western Cape was lucky so far, having only suffered from a subacute form at this stage.

In December 2020, the export value for pork in South Africa exceeded R56 million, according to the South African Pork Producers’ Organisation.

Industrial cleaning equipment supplier Industroclean managing director Emma Corder provided some guidelines on how to minimise an ASF outbreak:

• Limit staff movement;
• Wash hands before and after entering the piggery;
• Use disinfectant footpaths at piggery entrances;
• Reduce visitors to farms to essential workers only;
• Disinfect all delivery vehicles after each trip;
• Remove all organic matter from pens before disinfecting;
• Hose down floors, walls, ceilings and surfaces; and
• Clean and disinfect feeding troughs at least once a week.

For more news your way, download The Citizen’s app for iOS and Android.