Classical swine fever

Classical swine fever is a notifiable disease

Under Queensland legislation, if you suspect the presence of classical swine fever in pigs, you must report it to Biosecurity Queensland.

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Emergency Disease Watch Hotline 1800 675 888

Overview

Cause

Classical swine fever (CSF) is caused by a virus belonging to the pestivirus genus of the family Flaviviridae.

Description

CSF is a highly contagious viral disease of pigs, capable of spreading rapidly in susceptible pig populations. The disease is also commonly known as hog cholera. It is clinically similar to African swine fever but caused by a different virus.

Where the disease occurs

CSF is widespread in Africa, South America and Asia. In Europe, this disease has been eradicated from most countries.

The disease is not present in Australia although outbreaks have occurred and been eradicated in the past, the last one in 1961.

The disease in animals

There are three clinical forms of this disease:

  • an acute form with fevers, depression, loss of appetite and perhaps convulsions; initially there may be constipation but vomiting and diarrhoea are common late in the clinical course; there may be red or purplish skin blotching on ears, snout, limbs and abdomen
  • a chronic form with depression, loss of appetite, poor growth, fluctuating fevers and perhaps constipation and diarrhoea and even periods of normality
  • a mild form where poor growth is the most common feature but pregnant sows may abort, or give birth to stillborn piglets; surviving piglets may be born with tremors or deformities.

The death rate depends on the severity of the clinical signs. The very acute form results in very high death rates while the mild and chronic forms may pass undetected and the pigs then die from secondary infections.

Spread of the disease

Transmission of the virus occurs by direct contact with infected pigs or contact with contaminated pens, trucks or clothing.

Swill feeding of pigs with infected meat scraps is also an important means of spread to new areas or countries. The outbreaks in Australia occurred in this way.

The virus is killed by heat at 60°C for 10 minutes. The virus is very stable in a protein-rich environment and it can survive months in refrigerated meat and for years in frozen meat. The virus can be isolated from 'green' salami and pepperoni sausages but not after the required curing period and final acid treatment. The virus survives casings processing.

Control of the disease

The strategy in Australia is to eradicate the disease in the shortest possible time. This will be achieved by:

  • stamping out to remove the source of the infection
  • strict quarantine and movement controls
  • strict decontamination
  • tracing and surveillance to determine the source and extent of the disease
  • zoning to define infected and disease-free areas.

A vaccine is available overseas and may be used in exceptional circumstances if the disease becomes widespread and selected strategies are not being effective.

Can people get the disease

No.

Last updated 01 February 2012