KHV may become notifiable disease


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The deadly Koi Herpes Virus may become a notifiable disease and it could soon be a legal responsibility to inform the authorities of a suspected outbreak.

Ben Bradshaw MP, the Parliamentary Secretary for the Department for Environment, Food and Rural Affairs (Defra) and Junior Environment Minister, yesterday announced in Parliament that it was his intention to make KHV a notifiable disease in the UK, subject to discussions and consultation, bringing the disease in line with other serious fish diseases including Spring Viraemia of Carp (SVC) and Viral Haemorrhagic Septicaemia (VHS).

Bradshaw described the situation with Koi Herpes Virus as "very serious". Some experts believe that making the disease notifiable, as other serious animal diseases such as BSE, foot-and-mouth and rabies are, will make it easier for scientists to monitor and control the virus, and prevent it spreading to wild fish stocks. Unlike some other notifiable diseases, KHV poses no threat to humans.

A notifiable disease is a disease named in section 88 of the Animal Health Act 1981 or an Order made under that Act. Section 15(1) of the Act says that: "any person having in their possession or under their charge an animal affected or suspected of having one of these diseases must, with all practicable speed, notify that fact to a police constable."

Since the disease is not yet notifiable, there is no legal obligation for fish suppliers, fisheries, fish farmers or fishkeepers to inform the authorities if their fish become infected. Defra is also unable to prevent diseased fish being moved to other areas for fish infected by diseases that are not notifiable. But in the England and Wales fish movements to fisheries are governed by the Environment Agency (EA) through section 30 consents. The EA can control movements by treating KHV as a novel disease.

In order to make KHV a notifiable disease, England, Scotland, Wales and Northern Ireland need to reach an agreement on whether making the virus a notifiable disease is the best course of action to take. KHV will be made notifiable in the EU in the new directive, which comes in to force in the next two years.

Keith Davenport, Chief Executive of the Ornamental Aquatic Trade Association (OATA) told Practical Fishkeeping that the notifiable status of KHV could have an effect on the industry:

"The UK couldn't be declared KHV-free if the disease became notifiable, as it has been found quite widely in both the wild and in the ornamental sector. We would have to be an eradication zone. We would be in the same boat as SVC. If we want to be classed as an eradication zone, this means that we can only source fish from KHV-free areas. There seems to be difficulty in determining which areas are KHV-free and, of course, if this the case it follows that fish supply might be disrupted at some point in the future."

Davenport believes that the testing protocols used for determining the presence of the virus could be a problem. A great deal of research is being undertaken to produce fast and reliable laboratory procedures to accurately detect the virus in infected fish, but questions could be raised over the ability of the tests currently available to detect KHV in some circumstances.

"Normally when you have notifiable diseases", says Davenport, "you have chapters of information saying how to determine freedom from the disease and methods for determining whether you have got the disease present or not. But none of that is in place for KHV yet. You have to prove disease freedom for two years, but there is no formal approved method for approving absence or presence of the virus at the current time."

Under the current system there is no obligation to report suspected KHV outbreaks and a 200 charge is made to assess whether the virus is present in fish. Many believe that this has led to a false picture of how common KHV really is. While a great deal of suspected KHV cases are often attributed to severe bacterial infections, other cases likely to be caused by the virus may have gone unannounced, because fish dealers fear that confirmation of the disease on their premises will have a devastating effect upon their business.

Defra has reported only 16 confirmed cases of KHV in the UK's stillwater fisheries, however, in all likelihood, the number of cases is much greater than the figures suggest.