Defra has confirmed the presence of the deadly Koi Herpes Virus at four fish farms in the UK.
Brocket Hall Lakes in Welwyn Garden City, Hertfordshire, Burton Farm Fisheries in Nuneaton, Warwickshire, Alcott Farm Fishery near Redditch, Worcestershire, and Aldecar Lane Fishery Lakes in Nottinghamshire, have tested positive for the presence of the virus.
The results at each lake were confirmed following the deaths of fish showing the clinical signs associated with the disease, including white or necrotic patches on the gills, sunken eyes and sloughing mucus.
The symptoms of KHV, which is now officially known as Cyprinid Herpes Virus III (Cy-HV-3), typically show themselves only when the water temperature is between 16-28C, so infection is likely to have occurred before this date.
The fisheries will now need to work with Defra to establish and maintain disinfection procedures to prevent the spread of the virus to other waters.