Chikungunya virus – an Alphavirus (family Togaviridae).
Chikungunya is a viral disease that is spread by mosquitoes. Two important vectors are Aedes aegypti and Aedes albopictus, which also transmit dengue virus. These species bite during daylight hours with peak activity in the early morning and late afternoon. Both are found biting outdoors but Aedes aegypti will also readily bite indoors. There is no direct person-to-person transmission.
Nature of the disease
The name “chikungunya” derives from a Kimakonde word meaning “to become contorted” and describes the stooped appearance of sufferers with joint pain. Chikungunya is an acute febrile illness with sudden onset of fever and joint pains, particularly affecting the hands, wrists, ankles and feet. Most patients recover after a few days but in some cases the joint pains may persist for weeks, months or even longer. Other common signs and symptoms include muscle pain, headache, rash and leukopenia. Occasional cases of gastrointestinal complaints, eye, neurological and heart complications have been reported. Symptoms in infected individuals are often mild and the infection may go unrecognized or be misdiagnosed in areas where dengue occurs.
Chikungunya occurs in sub-Saharan Africa, south-east Asia and tropical areas of the Indian subcontinent, as well as islands in the south-western Indian Ocean (Map).
Risk for travellers
In countries or areas at risk and in areas affected by ongoing epidemics.
There are no specific antiviral drugs and no commercial vaccine. Treatment is directed primarily at relieving the symptoms, particularly the joint pain.
Travellers should take precautions to avoid mosquito bites during both day and night (Chapter 3).