Date: September 14, 2026
Reporter: Emilly Jordan
The United Kingdom government has imposed emergency disease-control restrictions on a fish-growing facility in Buckinghamshire following the confirmation of an outbreak of Koi Herpesvirus (KHV), a serious viral disease capable of causing widespread deaths among carp and related fish species.
The Centre for Environment, Fisheries and Aquaculture Science (CEFAS), acting on behalf of the Fish Health Inspectorate (FHI), confirmed the outbreak and established a designated containment area around the affected premises. The measures are intended to prevent the virus from spreading to other aquatic facilities, waterways and fish populations.
Koi Herpesvirus, also known as KHV disease, affects common carp and ornamental varieties of carp, scientifically known as Cyprinus carpio. The disease can cause significant mortality, particularly when environmental conditions favour the virus. According to UK authorities, infected fish may develop damage to their gills, rough or deteriorating skin, excessive loss of protective mucus and sunken eyes. These signs are particularly associated with water temperatures between approximately 16 and 28 degrees Celsius.
Despite the seriousness of the disease among fish populations, British authorities have stressed that the outbreak does not pose a risk to human health. The government has therefore focused its emergency response on preventing transmission among aquatic animals and protecting fish populations rather than imposing restrictions on people because of a human-health threat.
Under the statutory controls introduced following confirmation of the outbreak, the movement of aquatic animals into, out of or within the designated containment area has been restricted. Fish, eggs and reproductive material known as gametes cannot be moved without prior written permission from the Fish Health Inspectorate.
The restrictions are designed to prevent infected or potentially exposed fish from being transported to other locations where the disease could establish itself. Operators within the affected area must therefore seek authorization before moving susceptible aquatic animals or related materials.
The authorities have also introduced requirements concerning the disposal of dead fish and other affected aquatic materials. Dead aquatic animals, including eggs and gametes, must be disposed of using approved methods for Category 2 animal-by-product waste and in accordance with applicable environmental health requirements.
The Fish Health Inspectorate has instructed operators to immediately report any further deaths or evidence that the disease may have spread to other waters or facilities within the designated area. Officials must also be informed in advance of certain physical changes to affected premises, including alterations to site boundaries, changes to the number or size of water bodies and changes in how the site is used.
Requests for official consent to carry out activities covered by the restrictions must generally be submitted to the Fish Health Inspectorate at least five working days in advance, according to the government guidance.
The restrictions form part of a wider UK disease-control system that has been in place for Koi Herpesvirus for many years. KHV has been subject to statutory surveillance and movement controls in the United Kingdom since 2007, reflecting concerns about its potential to spread rapidly among susceptible fish populations.
Following confirmation of an outbreak, Fish Health Inspectorate officials are expected to visit affected premises to investigate the disease, monitor compliance with the restrictions and assess the effectiveness of biosecurity measures. Officials may also oversee measures such as culling infected or exposed fish, cleaning and disinfection of facilities and other steps considered necessary to eliminate or contain the disease.
The authorities have emphasized the importance of strengthened biosecurity at affected facilities. Operators are being encouraged to take measures designed to prevent the introduction of the virus and reduce the possibility of transmission to other fish, waterways or premises.
Koi Herpesvirus is classified as a listed disease under the Aquatic Animal Health (England and Wales) Regulations 2009. Because it can produce large-scale mortality among common and ornamental carp, confirmed outbreaks trigger formal government intervention and monitoring.
The Fish Health Inspectorate has also urged fish owners and operators to remain vigilant for signs of the disease. Anyone who suspects KHV, particularly where unusual fish deaths occur or affected fish display characteristic symptoms, is encouraged to contact the relevant authorities.
The Buckinghamshire outbreak highlights the importance of disease surveillance within Britain's aquaculture and ornamental-fish sectors. While the confirmed outbreak is not considered a threat to public health, authorities are taking precautionary measures to prevent the virus from spreading through aquatic populations and creating wider economic and environmental consequences.
The UK government's response is therefore centred on containment, movement controls, monitoring and biosecurity. Officials will continue inspecting the affected facility and assessing whether the disease has spread beyond the original premises before determining what further measures may be necessary.