From 1 June 2015, fisheries which have had a Koi herpesvirus (KHV) confirmed designation since 2012 - and those designated prior which have experienced a recurrence of infection - will be subject to a four year visual inspection programme.
Sentinel fish will no longer be introduced into these waters for testing. Instead each fishery will receive at least two formal visual inspections during the KHV disease outbreak season. They may also be subject to further spot checks throughout the year. However testing will be undertaken if clinical signs of disease or mortalities are found to reoccur in resident stocks. A confirmed designation will be removed if there is no suspicion of clinical disease after four years of inspection.
This change has been made following a review of the Fish Health Inspectorate’s (FHI) disease testing programme, and the completion of a study conducted by Cefas epidemiologists. Cefas concluded the use of sentinel fish afforded little extra confidence of KHV disease freedom when compared to an inspection only programme. Cefas epidemiologists’ report summary will be available on the Cefas GOV.UK blog.
Note for editors
- the FHI, acting on behalf of Defra, is the official service for the prevention and control of the spread of notifiable disease in England and Wales
KHV disease was made notifiable in England and Wales in 2007. Since then there have been almost 100 outbreaks of clinical disease in fisheries in England.
- infected fisheries are subject to controls – called confirmed designations - to prevent the further spread of the disease.
- up until 1 June 2015, confirmed designations were in place for at least four years. During the first two years a series of visual inspections were undertaken by the FHI at a time of year when clinical disease is most likely to occur. This was followed by at least two years of testing of naïve (sentinel) fish which were introduced into the infected waters in cages. Confirmed designations were removed from fisheries following successful completion of the four year programme. This involved having no re-occurrence of clinical KHV disease and achieving two sequential years of negative testing for KHV during this period.