CSF (hog cholera) was first reported in the United States in 1833 at a pig farm in southern Ohio. The disease became endemic to the United States and the country suffered several outbreaks in the late 19th and early 20th centuries. These continued outbreaks of CSF cost pig farmers as much as $50 million per year through the late 1950s.

The continuing impact of CSF on swine health and the economy led the USDA to initiate a Hog Cholera Eradication Program in 1961. This eradication program included a ban on classical swine fever vaccines made from a live virus (a potential source of new infection), the development of a rapid test to diagnose CSF, and the development of disinfectants that would kill the virus. The eradication program also developed methods to control the spread of the disease including the pre-emptive slaughter of animals with government monetary compensation. As a result of this initiative, the United States was declared free of CSF in 1978.

Potential routes of CSF introduction to the US

The United States remains one of a handful of countries considered free of the disease. However, CSF is endemic to many parts of the world including parts of Mexico, Europe and Asia. Therefore, CSF remains an agrosecurity risk to the US. There are several routes through which CSF may be reintroduced into the United States swine population including:

  • Smuggling of illegal pork and pork products into the US
  • Contact with infected wild swine
  • Consumption of contaminated meat or garbage by swine
  • Bioterrorism
  • Contaminated artificial insemination products
  • Physical transfer from human to pig

Potential Transmission Routes within the US

Although the United States swine herds are considered free of CSF, wild swine can act as a reservoir for the disease. Therefore, it is likely that an outbreak of CSF may occur through contact with our domestic herds with wild swine. In addition, the market for hunting wild swine is large. In order to supply this market, farmers may smuggle wild swine across state lines further spreading the disease.