Swine fever, having a high mortality rate, can cause severe economic losses among livestock. It is highly contagious and also infectious through feeding uncooked infected garbage. The disease often runs an atypical course with only a small number of animals becoming sick. Because clinical symptoms are not severe, outbreaks caused by low virulent strains may pass unnoticed for weeks or months, thus giving rise to a considerable spread of the virus. The virus is also very resilient. The classical swine fever virus has survived in processed ham for eighty-five days.
The clinical signs of classical swine fever and African swine fever are similar. In the field you cannot tell them apart and even at post mortem the signs are similar. Often only laboratory determination of the viral agent affords differential diagnosis.
Swine fever is widely spread throughout the tropical countries of Latin America and Southeast Asia. It is also evident, although controlled, in North America and Europe.
African swine fever was eradicated in Malta by killing every pig in the country.
Classical swine fever has occurred in Australia, where it is considered an exotic disease, four times, the last in 1961. Pig meat imports and illegal swill feeding (feeding uncooked food waste) was the probable cause.
In 1997 the import into Belgium of live pigs from Germany and certain regions of the Netherlands was banned. This followed 11 cases of Classical swine fever in Venhorst. The Dutch authorities undertook a cull of 30,000 pigs and Belgian farmers warned of a pig shortage.