Biosecure KOI Dossier

CEFAS has published a new Koi Herpes Virus risk assessment on the website www.efishbusiness.co.uk. The document is interesting but for those who want the bottom line it is sufficient to quote the following conclusion from the executive summary:
“….imported vaccinated carp may introduce wt-KHV.”
(wt = wild type)

1. To date, at least three known strains of KHV exist, each with differing symptoms and differing rates and percentages of mortality. The number of variants is most likely much higher. (Takashi Aoki et al, 2007)
2. KHV is highly contagious and can produce high (80% to nearly 100%) mortality in diseased populations of Koi and common carp (A. Dishon et al., 2005)
3. Neither the “immunisation” process nor the present vaccine that is used in Israel has categorically been proven effective for all three strains of KHV.
4. There is to date, no definitive test that proves whether a fish is an active carrier of KHV.
5. The virus can remain persistent and hidden in the organs of the host, without any expression of viral pathology for long periods of time. (A. Dishon et al. 2005)
6. Survivors of KHV are potential carriers. (S. St-Hilaire et al, 2005)
7. Research has shown the presence of asymptomatic KHV in goldfish and other aquatic species, leading to conjecture that these may be hosts and/or carriers of KHV. (J. Sadler et al, 2008, M. El-Matbouli et al, 2007, Kirsten Meyer, 2007).

Anyone interested in downloading my presentation on biosecurity made at the KHV workshop held in Israel in February 2008 can do so at this address.
The presentation can be downloaded in Dutch as well.
When the window opens, move the lower frame in order to read the comments I made during the presentation.
Watch this space for my article on Bisoecurity and Vaccination - due to be published soon.

“No system of testing and disease prevention by exclusion is ultimately as effective as a vaccination process.”
The above is one of the stupidest things I have heard!
Let’s all rush to get vaccinated for all the viruses that exist anywhere! Why isn’t a vaccine developed for every virus?

Medication and vaccination have traditionally played a major role in treating diseases but it is now widely accepted that they cannot, in isolation, prevent losses due to disease. Modern farming demands a holistic approach. Unless the background challenge from disease causing organisms can be controlled, and good management practices strictly followed, medication and vaccination alone are not capable of adequately protecting fish stocks. Fish must be given an environment in which the level of infection is controlled to the point where vaccination and medication can achieve beneficial effects. Biosecurity is the key to achieving this.

During the initial stages of a new viral disease, and KHV is a new viral disease if you compare it to any of the other known viruses, biosecurity makes much more sense than any medication or vaccine. We still do not know enough about the virus and it’s long term effects! Why take chances?

Instead of helping to eradicate the virus by destroying infected stocks immediately there are people out there who are willing to take chances with the unknown - just to make a quick buck.
Instead of locating, isolating, disinfecting and separating, there are those who are (albeit not intentionally) helping to spread the virus and/or helping to develop mutant and more virile strains of KHV.
Instead of supplying a fish that everyone can be sure has no chance of carrying the virus, there are some who want to convince us to vaccinate all our Koi so that they cannot be infected by a virus, that, although it exists in almost every Koi producing country, has still infected less than 1 percent of the total Koi population of the world!

This is what DEFRA (The UK Department for Environment, Food & Rural Affairs) had to say in their last newsletter concerning KHV:

Vaccinated carp
There are risks associated with the import of vaccinated and unvaccinated carp because we remain in the process of establishing the scientific evidence in respect of the disease risks they pose. Even if the risks are assessed as low, they are risks that nonetheless exist. It is therefore for fishery operators themselves to decide whether the level of risk of stocking fish is acceptable to their business. In the case of vaccinated carp, that assessment should also take account of the fact that the vaccine used on live fish for export to the UK has no marketing authority for use in the UK or other parts of the EU and, as far as we know, no evaluation has been carried out by those engaged in this trade on the possible risks that imported vaccinated carp may pose to indigenous fish in UK environmental conditions.