In May 2025, the Animal and Plant Health Agency (APHA) reported fragments of West Nile virus genetic material in a small sample of mosquitoes collected in Nottinghamshire during July 2023, as part of the RADAR surveillance programme. There is no evidence to suggest ongoing circulation of the virus in animals or mosquitoes, and there have been no locally acquired West Nile virus detections in humans in the United Kingdom. The UK Health Security Agency (UKHSA) has assessed the risk to the general public as very low.

The UKHSA partners with the Department for Environment, Food and Rural Affairs and the APHA on the surveillance of mosquitoes, birds, horses, and humans for a range of emerging infectious diseases, including West Nile virus.

Human health surveillance relevant to the West Nile virus includes routine testing of travellers who have returned from overseas areas affected by West Nile virus with compatible clinical syndromes, including undiagnosed encephalitis.

The NHS Blood and Transplant service screens donors returning from affected areas based on their travel history, and partners with the UKHSA on a research study to understand the risk of climate-related emerging infections, including West Nile virus.

The UKHSA’s clinical testing protocols require that any undiagnosed human cases of encephalitis are referred to the UKHSA’s Rare and Imported Pathogens Laboratory. They will be routinely tested for West Nile virus, regardless of travel history.

Following the detection in mosquitoes, the UKHSA issued a briefing note to National Health Service clinicians nationally on the potential clinical presentation of vector borne diseases, including West Nile virus.

The UKHSA Imported Fever Service offers a clinical advisory and testing service to support doctors managing domestic cases of undiagnosed encephalitis. The British Infection Association’s testing guidelines for encephalitis are being updated to include consideration of the West Nile virus.

The United Kingdom Health Security Agency (UKHSA), along with local authority partners, developed a Tick Awareness Toolkit which has been shared with local authorities and other organisations to deliver tick awareness messaging, including safety relating to ticks and the promotion of tick-bite prevention behaviours. This can be deployed in a variety of settings, including general practitioner surgeries and outdoor spaces. The toolkit also encourages local authorities to evaluate the impact of any campaign work. In order to increase awareness of tick-borne encephalitis amongst clinicians UKHSA has cascaded a briefing note to National Health Service clinicians and has presented on the disease to national and international conferences to inform relevant specialist groups.

People whose capability for work is affected because they are disabled or have a health condition, including people who have encephalitis, may be eligible for New Style Employment and Support Allowance and/or Universal Credit, subject to satisfying their eligibility conditions. The Work Capability Assessment determines an individual’s capability for work. For people found to have limited capability for work, their Jobcentre work coach uses their discretion to set work-related activity, appropriate to the claimant's circumstances and capability, to help them prepare to start work when they are able. People who have limited capability for work and work-related activity are not required to carry out any work-related activity, but can do so if they wish.

People who have encephalitis may also be eligible for Personal Independence Payment, to help meet the extra costs of living faced by disabled people and people with health conditions.

Training programmes for healthcare professionals must meet the standards set by the regulatory body for their profession.

Employers in the health system are responsible for ensuring that their staff are trained to the required standards to deliver appropriate treatment for patients.

Decisions about the National Health Service workforce in Northern Ireland, Scotland and Wales are a matter for the devolved administrations of those countries.

Data on the total number of cases of encephalitis in the United Kingdom in the last five years is not held. As health is a devolved matter, it would be for the devolved administrations of Scotland, Wales and Northern Ireland to make decisions about collecting data in their respective countries.

The provision of after-care for people who have been treated for encephalitis is a local matter. Waiting times for patients with encephalitis will vary depending on their level of need and the judgement of clinicians, who are best placed to make such decisions.

Data on the total number of cases of encephalitis in the United Kingdom in the last five years is not held. As health is a devolved matter, it would be for the devolved administrations of Scotland, Wales and Northern Ireland to make decisions about collecting data in their respective countries.

The provision of after-care for people who have been treated for encephalitis is a local matter. Waiting times for patients with encephalitis will vary depending on their level of need and the judgement of clinicians, who are best placed to make such decisions.

There are currently no specific plans.

NHS England works with partners such as voluntary sector organisations to synchronise communications activity in line with many annual awareness days. The NHS England communications team may also provide support to maximise the reach of established campaigns.

There are no specific plans.

NHS England works with partners such as voluntary sector organisations to synchronise communications activity in line with many annual awareness days. The NHS England communications team may also provide support to maximise the reach of established campaigns.

Curricula for undergraduate medical training are set by individual medical schools and by the relevant medical Royal College for postgraduate training, and have to meet the education standards set by the General Medical Council (GMC).

Curricula emphasise the skills and approaches that a doctor must develop to deal effectively with whatever is presented to them, in order to ensure accurate and timely diagnoses of conditions such as encephalitis and treatment plans for their patients.

The current review of postgraduate curricula by the GMC provides an opportunity to ensure curricula reflect general professional capabilities and to ensure all training requirements are met.

Curricula for undergraduate medical training are set by individual medical schools and by the relevant medical Royal College for postgraduate training, and have to meet the education standards set by the General Medical Council (GMC).

Curricula emphasise the skills and approaches that a doctor must develop to deal effectively with whatever is presented to them, in order to ensure accurate and timely diagnoses of conditions such as encephalitis and treatment plans for their patients.

The current review of postgraduate curricula by the GMC provides an opportunity to ensure curricula reflect general professional capabilities and to ensure all training requirements are met.

The Department has not made a recent assessment of the diagnosis of encephalitis or the level of National Health Service support available to people who have been diagnosed with encephalitis.

The new Emergency Care Data Set will be introduced from October 2017, and will improve the recording of the diagnosis of encephalitis in English accident and emergency departments, and allow a greater understanding of the current scope and scale of the problem.

The Department has not made a recent assessment of the diagnosis of encephalitis or the level of National Health Service support available to people who have been diagnosed with encephalitis.

The new Emergency Care Data Set will be introduced from October 2017, and will improve the recording of the diagnosis of encephalitis in English accident and emergency departments, and allow a greater understanding of the current scope and scale of the problem.

Acute encephalitis is a notifiable disease but given most cases are mild, in practice the majority of cases are not reported. The numbers reported for England and Wales in 2010-15 are available to view here:

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/572816/NOIDS_Annual_Totals.xlsx