Yes. Infected prawns do not pose any threat to human health or food safety.

Recent testing conducted for Four Corners found traces of the virus present in 30 per cent of samples purchased from a range of supermarkets in south-east Queensland.

What is white spot?

It's a highly contagious viral disease that affects crustaceans including prawns, crabs, yabbies and lobsters. Marine worms are also considered to be carriers of the disease.

The disease kills prawns and outbreaks can cause mass mortality in prawn farms.

Signs of white spot in prawns include:

A loose shell with visible white spots and pink to red discolouration

A loose shell with visible white spots and pink to red discolouration Unusual swimming patterns

Unusual swimming patterns Reduced feeding

Reduced feeding Farmed prawns may gather at the edge or surface of ponds

White spot is widespread in prawn farming regions of Asia and the Americas, where it has led to severe economic losses.

Dead prawns on a Logan River farm in the aftermath of the 2016 white spot outbreak. ( Supplied: DigsFish Services )

How does it spread?

The disease is spread through the movement of infected animals or contaminated water. Birds that feed on and move infected animals can spread the disease.

Fishermen using infected prawns as bait can also spread the disease, that is why Australian authorities have urged fishermen not to fish with prawns intended for human consumption.

In 2016, an outbreak of the disease in south-east Queensland forced seven prawn farms to destroy their stock.

That outbreak has so far cost the industry more than $40 million.

It is believed the virus entered the ecosystem via supermarket prawns being used as bait.

Earlier this year the Queensland Government confirmed that the virus had been detected in wild prawns in Moreton Bay.



Watch Linton Besser's investigation, Outbreak, tonight on Four Corners at 8.30pm on ABC TV or on ABC iview.