Medicines for Tick-borne encephalitis

What it is

Tick-borne encephalitis (TBE) is a viral infection spread to people through the bite of infected ticks. It occurs in parts of mainland Europe and Asia (in forested and rural areas where infected ticks are present), and is not naturally present in most of the UK, though the risk to travellers depends on the destination and activities. The TBE virus is spread mainly through tick bites (ticks pick up the virus from animals); less commonly, it can be spread by consuming unpasteurised milk or dairy products from infected animals. It is not spread from person to person. The risk is mainly to people who spend time in forested or rural areas in affected regions during the tick season (spring to autumn), for example when walking, hiking, camping, or working outdoors. Many people infected with the TBE virus have no symptoms or only a mild, flu-like illness. In some people, however, the infection progresses to affect the nervous system, causing meningitis (inflammation of the linings of the brain and spinal cord) or encephalitis (inflammation of the brain), which can be serious. The illness often has two phases: an initial flu-like phase (with fever, tiredness, headache, and aches), which may be followed, after a symptom-free interval, by a second phase in which the nervous system is affected — with a high fever, severe headache, a stiff neck, and features such as confusion, drowsiness, problems with movement or coordination, weakness or paralysis, and, in severe cases, more significant neurological effects. The serious form can, in some cases, cause lasting neurological effects or, rarely, be fatal. There is no specific antiviral treatment for TBE, so treatment of the serious form is supportive care in hospital. Because of this, prevention is important for travellers to affected areas, and there are two main approaches: a vaccine against TBE, recommended for certain travellers (based on the destination, activities, and season); and avoiding tick bites (and not consuming unpasteurised dairy products in affected areas). The key messages are that tick-borne encephalitis is a viral infection spread by tick bites in parts of Europe and Asia that can affect the brain, that most infections are mild but some are serious, and that a vaccine (for certain travellers) and avoiding tick bites protect travellers to affected areas.

How it is treated

The approach to tick-borne encephalitis centres on prevention for travellers to affected areas — through vaccination for certain travellers and avoiding tick bites — and supportive care for the serious cases, as there is no specific antiviral treatment. For travellers, prevention is the key, and travel health advice helps assess the risk (based on the destination, the areas and activities planned — particularly time in forested or rural areas — and the season) and recommend measures; travellers to affected regions who will be at risk should seek travel health advice before travelling. Two main preventive measures are used: the TBE vaccine, which is recommended for certain travellers — particularly those who will spend time in forested or rural areas in affected regions during the tick season, or with higher-risk activities — and is given as a course before travel, so planning ahead is important; and avoiding tick bites, which is important for everyone at risk in affected areas (and protects against other tick-borne infections, such as Lyme disease) — measures include wearing suitable clothing (such as long sleeves and trousers, tucking trousers into socks) in tick habitats, using insect repellent, checking the skin and clothing for ticks after being outdoors and removing any ticks promptly and correctly (using fine-tipped tweezers or a tick tool, grasping close to the skin and pulling straight out), and being aware of tick habitats; in affected areas, avoiding unpasteurised milk and dairy products also removes that route of infection. There is no specific antiviral treatment for TBE, so for the cases that develop the serious form (meningitis or encephalitis), treatment is supportive care in hospital — managing the symptoms and complications, supporting the body’s functions, controlling seizures, and providing rehabilitation and follow-up for any lasting effects in those who recover. Prompt medical attention for symptoms — particularly a feverish illness followed by neurological symptoms such as a stiff neck, severe headache, confusion, or drowsiness — after travel to an affected area is important. The reassuring messages are that tick-borne encephalitis is not naturally present in most of the UK, that the risk to travellers depends on the destination and activities (mainly time in forested/rural areas in the tick season), that most infections are mild, and that effective prevention — a vaccine for certain travellers and avoiding tick bites — protects travellers; so seeking travel health advice before visiting affected areas, taking tick-bite precautions, and seeking urgent care for a feverish illness with neurological symptoms after relevant travel are the key points.