Vesicular exanthema

Vesicular exanthema is a notifiable disease

Under Queensland legislation, if you suspect the presence of any vesicular disease in pigs, you must report it to Biosecurity Queensland.

Call us  13 25 23 or
Emergency Disease Watch Hotline  1800 675 888

Overview

Causes

Vesicular exanthema (VE) is caused by a virus belonging to the family Calciviridae.

Description

VE is an acute viral disease of pigs. The disease is characterised by the formation of blisters that are clinically indistinguishable from those caused by foot-and-mouth disease. Rapid identification of the virus is essential to rule out the presence of foot-and-mouth disease.

A similar disease occurs in marine mammals (such as sea lions, fur seals and elephant seals).

Where the disease occurs

The disease first appeared in California in 1932 and was finally eliminated from the United States in 1956. It has been identified in Iceland after pigs were fed raw garbage swill from a United States military base. Related viruses have been identified all along the Pacific seaboard of North America.

VE has never been identified in pigs in Australia.

The disease in animals

Sickness rates in pigs are high but death rates low, except in young piglets.

The earliest clinical sign is a marked fever with the pigs being lethargic, not eating and unwilling to stand. Sows may abort and lactating sows may stop producing milk.

The disease may not be noticed in a herd until obvious lameness and blisters are seen on the snout and in the mouth (on the lips, gum or tongue); on the soles, the skin between the toes, cuticle and claws; and occasionally on the teats or udder. In some outbreaks, the foot lesions may predominate and in other outbreaks they may be insignificant.

Many pigs recover quickly and uneventfully. In other cases complications may occur as a result of secondary bacterial infection.

Spread of the disease

The feeding of swill contaminated with material from infected marine mammals or infected pork products is the principal means of spread. Movement of infected pigs is a major cause of secondary spread of the disease. The most likely way the disease could be introduced into Australia is via uncooked swill, the feeding of infected, imported fishmeal to pigs or perhaps by wild pigs scavenging dead marine animals on the seashore.

VE virus is reasonably resistant to inactivation in the environment. It retains infectivity in contaminated food scraps for up to 4 weeks at 7°C. The virus survives longer at cooler temperatures but is inactivated in acid conditions below pH 3.

Control of the disease

The strategy is:

  • immediate stamping out to eliminate the source of virus
  • quarantine and movement controls
  • thorough decontamination and destruction of contaminated pigmeat products
  • tracing and surveillance to determine the source and extent of disease
  • zoning to define infected and disease-free areas.

Tracing and destruction of any contaminated pigmeat products will be essential to limit the risk of secondary infection. Vaccination has no useful role in the control of this disease.

Can people get the disease?

No.

Last updated 01 February 2012