Viral haemorrhagic septicaemia

This virus has a tremendous host range, across wild and farmed fish species. This disease has no cure and could wipe out up to 80% of a fish population.

About viral haemorrhagic septicaemia

This virus infects a broad range of wild and farmed freshwater and marine species, including rainbow trout, turbot, and Japanese flounder. It can infect fish at all life stages, but particularly young fish. Depending on the version of the virus, it can kill up to 80% of a fish population. If a fish survives, it can become a carrier and pass it on to healthy fish.

Why this is a problem for New Zealand

Due to the huge range of species this virus can infect, some New Zealand species are likely to be susceptible. In Europe, the virus is considered one of the most serious viral diseases in trout aquaculture.

As with many viral diseases of fish, there is no specific treatment or cure. Once established, aquatic diseases are extremely difficult to eradicate.

How it could get here

The virus could get to New Zealand through:

  • infected live or dead finfish, including ornamental fish
  • contaminated equipment (for example, nets and containers)
  • contaminated water.

Even freezing an infected fish and thawing it won't kill the virus. MPI has strict measures in place to limit the chances of the virus making it through the border.

Where you might find it

Infected fish could be in fresh water or the marine environment, in both farmed or wild populations.

How to identify it

Diagnosing fish diseases requires laboratory testing. Signs of fish diseases are difficult to tell apart. This virus may show different signs in different fish species. Also, infected survivors can show no signs of the disease, they're covert carriers.

If you find large numbers of dead fish

  • photograph them
  • take a sample (put a fish in a plastic bag and refrigerate)
  • take note of the location and any landmarks
  • call 0800 80 99 66

Note: This information is a summary of this disease's potential impacts on New Zealand.

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