Chikungunya is a viral illness spread by mosquito bites in tropical and subtropical regions. It is generally not found in the UK, but travellers can catch it abroad. The infection usually causes high fever, severe joint pain, headache, muscle aches and rash. Most people recover in about a week, but joint pain can last longer in some cases. Although it is rarely life-threatening, the illness can be very unpleasant and disruptive.