Important outbreaks

While outbreaks of CSF are always important to the victims, they assume a particular importance when they occur in countries that are considered to be free of CSF. Most countries in Western Europe had eradicated CSF by the 1980s and had ceased vaccination. Small outbreaks sporadically occurred in countries like Germany and Italy where the wild boar population was known to be infected and unsafe practices resulted in domestic pigs becoming infected. However, in 1997 an outbreak of CSF occurred in the Netherlands in areas of dense pig farming that resulted in the loss of 11 million pigs and cost $2.3 billion to eradicate. Although the outbreak originated in Germany and was believed to have been introduced into The Netherlands by a contaminated truck used for transporting pigs, molecular genetic studies of the German and Netherlands outbreak viruses demonstrated that it differed at group level from the viruses circulating in European wild boar populations and most likely came from in Asia. In 2001 the United Kingdom suffered an outbreak and although the origin was not traced with certainty, the first confirmed case occurred in outdoor pigs and the virus was again of the Asian type.

An outbreak of CSF was documented in South Africa in 1900 in the Western Cape that spread and was only eradicated in 1918, three years before African swine fever was described for the first time as a different disease. Apart from Madagascar, where CSF was introduced during the colonial period and became endemic, CSF was not reported from Africa again until 2000, when the island of Mauritius suffered an outbreak apparently due to an introduction from Madagascar. Eradication was accomplished by 2002 with the help of vaccination. In 2005 CSF was reported from South Africa, first in the Western Cape and then in the Eastern Cape. Although only a few commercial farms were infected, the disease spread rapidly among pigs in the smallholder sectors. In the Western Cape smallholder pig farmers were just recovering from a devastating outbreak of porcine reproductive and respiratory syndrome (PRRS) when once again all their pigs had to be culled to control CSF. In the Eastern Cape, as indicated above, almost half a million pigs belonging to nearly as many households were culled, an operation that continued until 2007.