Encephalitis
Overview
Encephalitis is an uncommon but serious condition in which the brain becomes inflamed (swollen).
Symptoms
Encephalitis usually starts off withflu-like symptoms, such as a high temperature andheadache. More serious symptoms come on over hours, days or weeks, including: confusion or disorientationseizures or fitschanges in personality and behaviourdifficulty speakingweakness or loss of movement in some parts of the bodyloss of consciousness Dial 999 for an ambulance immediately if you or someone else has these serious symptoms.
Causes
It's not always clear what causes encephalitis, but it can be caused by: viral infections – very rarely, encephalitis may be caused by the common viruses that causescold sores(herpes simplex) orchickenpox(herpes varicella) spreading to the braina problem with the immune system, the body's defence against infection – sometimes something goes wrong with the immune system and it mistakenly attacks the brain, causing it to become inflamedbacterial or fungal infections – these are much rarer causes of encephalitis than viral infections Some types of encephalitis are spread by mosquitoes (such asJapanese encephalitis), ticks (such astick-borne encephalitis) and mammals (such asrabies). You cannot catch encephalitis from someone else.
Treatment
Encephalitis needs to be treated in a hospital. The earlier treatment is started, the more successful it's likely to be. Treatment depends on the underlying cause, but may include: antiviral medicinessteroid injectionstreatments to help control the immune systemantibioticsorantifungal medicinespainkillers to reduce discomfort or a high temperaturemedicine to control seizures or fitssupport with breathing, such as oxygen through a face mask or a breathing machine (ventilator) How long someone with encephalitis needs to stay in hospital can range from a few days to several weeks or even months.
Prevention
It's not always possible to prevent encephalitis, but some of the infections that cause it can be prevented with vaccinations. These include the: measles, mumps and rubella (MMR) vaccine– a routine vaccination offered to all children in EnglandJapanese encephalitis vaccine– recommended for travellers to at-risk areas, such as parts of Asiatick-borne encephalitis vaccine– recommended for travellers to certain parts of Europe (but not the UK) and Asiarabies vaccination– recommended for travellers to at-risk where access to medical care is likely to be limited.Find out about rabies risks in terrestrial animals by country on GOV.UK. Speak to a GP surgery if you're not sure whether your vaccinations are up to date, or you're planning to travel abroad and do not know if you need any vaccinations.