Chikungunya fever is an illness caused by a virus. The virus infects you when you are bitten by a certain type of mosquito. You cannot catch chikungunya fever in the UK, but you may be at risk of catching it when abroad. It usually causes a high temperature (fever) and joint pains. In most people it goes away completely after one or two weeks. In a few people it may be a more serious illness. There is no specific treatment.
Always check travel health websites before travelling to get the latest information on infections in the area to which you are going. Chikungunya can be prevented by taking measures to avoid mosquito bites.
What is chikungunya fever?
Chikungunya fever is an illness caused by a virus. The virus gets into your system when you are bitten by a particular type of mosquito. The type of mosquito which transmits the chikungunya virus is called an Aedes mosquito. These mosquitoes tend to bite in the daytime rather than at night.
The mosquito carries the virus after feeding from (biting) another person or animal who has the chikungunya infection. The virus multiplies in your bloodstream, causing you to become unwell usually 4-8 days after the mosquito bite. The virus causes you to develop a temperature (fever) and joint pains. There may be other symptoms.
How do you catch chikungunya fever?
Anyone bitten by a mosquito infected with the chikungunya virus can get the illness. It only occurs in certain parts of the world. It only occurs in countries where it is warm enough for the mosquito to survive. It is not warm enough for this type of mosquito in the UK, so you cannot get the infection in the UK. However, if you travel to a country where there is an outbreak of chikungunya fever, you may become infected if you are bitten by an infected mosquito.
Anybody at any age can get chikungunya fever. However, it tends to be more severe in certain groups of people. This includes:
- Newborn babies and very young children.
- People aged over 65 years.
- People with other medical conditions.
Up until 2013, chikungunya fever was mainly a risk only in certain parts of Africa and Asia. In 2013, however, cases were reported in the Caribbean and in North and South America. Since then there have been outbreaks across the Caribbean and the Americas, with many thousands of people catching the virus.
You cannot catch chikungunya fever from another person. It is only passed on if you are bitten by a mosquito which has bitten another person or animal infected with the virus. The exception to this is that newborn babies have been known to develop chikungunya fever shortly after birth if their mother has the infection. Infection with chikungunya fever during pregnancy may also result in infection and problems for the developing baby.
How common is chikungunya fever?
It is very variable how common chikungunya fever is because it tends to occur in outbreaks. Since being first reported in the Caribbean and the Americas, there have been more than 1.2 million cases in these regions.
In the UK it is very rare. There have been more cases since the outbreak in the Caribbean and Americas. There were 295 cases reported in 2014 in England, Wales and Northern Ireland. All these illnesses happened in people who had travelled abroad. Most of them had been to the Caribbean or South America. Before 2014, there were very few cases and mostly they had caught the virus in India or Southeast Asia.
There have been a few cases of chikungunya fever closer to the UK - in the South of France and in Italy.
What are the symptoms of chikungunya fever?
The symptoms of the illness usually start four to eight days after being bitten by the infected mosquito. It starts with a high temperature (fever) and joint pains. The joint pains may be very severe. The word "chikungunya" comes from an African word which means "that which bends up". This is because people with the illness may be bent over in pain. Any joint can be affected but most commonly the joints of the hands, wrists and ankles are painful.
Other symptoms which may be present include:
- Feeling tired
- Feeling sick (nausea)
- A rash
- Muscle pains
- A headache
Usually the symptoms last one or two weeks, and then completely settle. In a few people, however, the joint pains can carry on for weeks or months after the infection has gone.
Very rarely more serious symptoms occur. These are more likely in more vulnerable people. For example, young babies, the elderly or people with other medical conditions may be more prone to the more serious symptoms. These more unusual complications include:
- Pains in the eye or loss of vision.
- Fits (seizures).
- Infections in parts of the brain (meningitis or encephalitis).
- Watery stools (diarrhoea).
- Breathing problems.
- Heart problems.
- Kidney problems.
- Liver infection.
Are there any tests for chikungunya fever?
A blood test can be taken to confirm chikungunya. In the UK it has to be sent to a special laboratory for rare imported diseases. The blood sample can be checked to see if the virus can be found. It may also be checked for special proteins called antibodies which are produced by your immune system to fight the virus.
What is the treatment for chikungunya fever?
There is no specific medication which tackles the virus itself. Normally you will be advised to take medicines such as paracetamol or ibuprofen to help with the joint pains and high temperature (fever). You will be advised to drink plenty of fluid. People who become very unwell may need to have extra care in hospital.
What is the outcome (prognosis)?
Most people make a full recovery within one to two weeks. Some people may be left with joint pains which can go on for weeks or months.
A very few people have complications (see the "symptoms" section above). It is rare to die from chikungunya fever but it can happen occasionally.
How can I prevent chikungunya fever? Advice for travellers
When travelling abroad, always check the NHS travel websites for the latest information. The "Fit for Travel" website is listed at the end of this leaflet. It will give you information about health risks associated with your destination.
If travelling to an area where chikungunya fever occurs, take all possible precautions to avoid being bitten by a mosquito. For example:
- Use insect repellent. Those containing a chemical called N, N-diethylmetatoluamide (DEET) are known to be the most effective. Apply insect repellent regularly and re-apply after swimming. If also using sunscreen, apply the insect repellent after the sunscreen.
- Sleep in rooms with mosquito screens and/or mosquito nets.
- The use of mosquito coils may be helpful outside.
- Wear clothing that protects you from bites - ie long sleeves and long trousers. For areas affected by chikungunya fever, you need this type of clothing even in the daytime. This is because the Aedes mosquitoes tend to bite in the daytime, unlike other types which usually bite in the evenings. There are some insecticides available which can be sprayed on to clothing.
There is no vaccine available to prevent chikungunya infection.
If you develop a high temperature (fever) or joint pains while abroad, or shortly after you return, seek medical advice.
Dr Mary Harding
Dr Mary Harding
Dr Hayley Willacy