Overview
Chikungunya is an illness caused by the chikungunya virus. It is carried by two kinds of Aedes mosquito, the same mosquitoes that spread dengue, and they bite mainly during daylight hours.
Symptoms usually appear four to eight days after the bite, and sometimes anywhere from two to twelve days. The joint pain is the feature that sets chikungunya apart from other mosquito-borne fevers, and it is often severe enough to make ordinary movement difficult.
Most people recover within a week or two. Severe illness and death are rare, and happen mainly in newborn babies infected around the time of birth, in older people, and in people with other long-term conditions.
Symptoms
Chikungunya usually begins abruptly:
- Sudden fever
- Severe joint pain, often in both hands, wrists, ankles and feet
- Swelling of the joints
- Muscle pain and headache
- Nausea and marked tiredness
- A rash, in some people
The fever usually settles within about a week. The joint pain can take much longer, and in some people it comes and goes for months. Because dengue causes a very similar fever and can be far more dangerous, doctors often test for both.
When to see a doctor
See a doctor within a day or two for fever with joint pain that is not settling, for joint pain or swelling continuing after the fever, and for fever in an older person or in anyone with heart, kidney, liver or diabetes problems.
Causes
The chikungunya virus passes to people through the bite of an infected female Aedes mosquito. The mosquito picks up the virus by biting someone who already has it in their blood, usually during the first week of their illness, and can then pass it on to others.
The virus is not passed directly from person to person by touch, coughing or sharing food. It can pass from a mother to her baby around the time of birth.
Risk factors
- Water stored or collecting in and around the home, giving mosquitoes places to breed
- Living or working in an area where an outbreak is under way
- Being outdoors, uncovered, during the day without repellent
- Newborn babies, where the mother is infected around delivery
- Older age
- Long-term conditions such as diabetes, or heart, kidney or liver disease
Complications
The commonest lasting problem is joint pain and stiffness that continues after the fever has gone. It may improve over weeks, but for some people it comes and goes for months or years, and it can make everyday tasks and work difficult.
Serious complications are uncommon and occur mainly in newborn babies, in older people and in those with other long-term illnesses, who may need hospital care.
Prevention
- Emptying and scrubbing coolers, tanks, buckets, pots, plant trays and tyres once a week
- Keeping water storage containers covered
- Using a mosquito repellent on exposed skin during the day
- Wearing full sleeves and trousers, especially in the morning and late afternoon
- Fitting screens on windows and doors
- Protecting anyone who is ill from further mosquito bites during the first week, so the virus does not spread on
Diagnosis
Chikungunya is diagnosed from the pattern of symptoms together with a blood test. In the first week of illness the virus itself can be detected in the blood. After that, tests look for the antibodies the body has made against it.
Testing for dengue, and often for malaria and typhoid, is usually done at the same time, because these illnesses overlap and the treatment and the level of watchfulness differ. A blood count may also be checked to follow the .
Treatment
There is no medicine that acts against the chikungunya virus itself, so treatment is aimed at comfort and at spotting anything serious. Rest, plenty of fluids, and paracetamol for fever and pain are the mainstay, and most people can be looked after at home.
Aspirin and anti-inflammatory painkillers such as ibuprofen are avoided until dengue has been ruled out, because they can add to the risk of bleeding. Once that is clear, a doctor may consider other medicines for joint pain that is not settling.
For joint stiffness in the weeks afterwards, gentle movement, warm compresses and physiotherapy often help. Anyone who cannot keep fluids down, or who develops any of the warning signs above, is assessed in hospital.
Myths and facts
Things people often say about this. Open each one to see what is true.
Myth“Mosquitoes bite at night, so a net over the bed is enough.”What is true?
Fact
The Aedes mosquitoes that carry chikungunya bite mainly during daylight hours. A net at night protects against some other mosquitoes but not these, so daytime measures matter just as much: repellent on exposed skin, full sleeves, and screens on windows and doors.
Myth“These mosquitoes breed in drains and dirty water, so a clean house is safe.”What is true?
Fact
Aedes mosquitoes breed in small collections of standing water in and around the home: coolers, overhead and ground tanks, buckets, pots, plant trays, discarded tyres and construction sites. Emptying and scrubbing these every week does more to stop chikungunya than anything else.
Myth“A stronger painkiller will deal with joint pain this bad.”What is true?
Fact
WHO and the CDC both advise paracetamol for the pain of chikungunya, and advise against aspirin and anti-inflammatory painkillers such as ibuprofen until dengue has been ruled out, because they raise the risk of bleeding. Once dengue is excluded, a doctor may add other options for the lingering joint pain.
Myth“The fever has gone, so the joint pain must be something else now.”What is true?
Fact
Joint pain from chikungunya often outlasts the fever. WHO notes that it may last a few days but can be prolonged, continuing for weeks, months or even years in some people. It is worth telling the doctor if it is not improving, because there are ways to help.
Myth“Chikungunya spreads from person to person, so keep the patient in a separate room.”What is true?
Fact
It does not pass directly between people. It spreads only through mosquito bites. During the first week of illness a mosquito that bites the patient can pick up the virus and pass it to others, so protecting the patient from bites protects the rest of the household.
Questions to ask your doctor
Tick the ones you want answered and take them with you.
Common questions
How do I know whether this is chikungunya or dengue?
You cannot tell them apart by symptoms alone in the first days, which is why blood tests are done. Severe joint pain that dominates the illness points towards chikungunya, but the safe approach is to treat every such fever as though dengue is possible: paracetamol only, plenty of fluids, and a quick return if warning signs appear.
My joints still hurt two months later. Is that normal?
It is common. WHO notes that the joint pain of chikungunya may continue for weeks, months or even years in some people. Tell your doctor, because gentle exercise, physiotherapy and, where suitable, particular medicines can make a real difference.
What can I do at home while I recover?
Rest, drink fluids steadily through the day, and use paracetamol for fever and pain. Keep away from mosquito bites during the first week, with repellent and full sleeves, so that a mosquito biting you does not carry the virus on to someone else. Go back to the doctor at once if any of the warning signs appear.
