What is Chikungunya Fever?
Chikungunya fever (Chik) is a viral infection transmitted to humans by biting Aedes mosquitoes (A. aegypti, A. albopictus and A. polynesiensis). These are tropical and subtropical mosquitoes found in the warmer parts of the world (especially Asia) and the United States and the Mediterranean Basin. Chikungunya fever is caused by the Chikungunya virus, an Alphavirus, and a member of the Togaviridae family.
Chikungunya fever is commonly found in East Africa, Southeast Asia and in the Indian sub-continent. In summer 2007, an outbreak was reported in the Emilia-Romagna region of North-East Italy, and this region is now considered an area where Chikungunya virus transmission takes place.
What are the signs and symptoms of Chikungunya Fever?
The incubation (between being bitten and developing symptoms) ranges from 1 to 12 days, with an average of 4 to 7 days. The main clinical features are fever, joint pain, muscle pain and headache. Joint pains are a characteristic symptom. Benign haemorrhagic symptoms, such as bleeding from the nose or gums, are possible, in particular in children.
While most cases recover without complications, the development of a more chronic phase is possible, with persistent joint pains. Recovery may take several weeks for these patients, coinciding with pronounced lethargy. Younger people tend to recover in a matter of a one or two weeks; middle-aged and elderly tend to take one to three months for full recovery.
During the outbreak in La Réunion in 2006, severe complications were described, including respiratory failure, cardio-vascular failure, or meningo-encephalitis. Although more than 1700 cases were confirmed in La Réunion, it was estimated that there were in excess of 100,000 cases in total. Although generally a mild illness, during this outbreak in La Réunion , more than 200 deaths were reported, primarily in elderly people.
People who have visited an area where Chikungunya virus transmission is known or suspected to occur, and who develop a high fever along with unexplained joint pain in the 12 days after their return, are advised to seek medical attention.
Chikungunya fever is a notifiable disease in Ireland.
What is the treatment for Chikungunya Fever?
Treatment for Chikungunya fever involves pain relief and anti-fever medication. There is currently no vaccine against the virus responsible for causing Chikungunya. Travellers to affected areas are advised to take sensible precautions against mosquito bites (see our section on protecting yourself from mosquito bites).
Who are at risk of Chikungunya Fever?
Although the risk of serious disease is low, certain groups are at higher risk, including:
- Pregnant women
- People with weakened immune systems (such as patients living with cancer or HIV/AIDS) and
- People suffering from severe chronic illness (such as heart, lung or kidney disease and diabetes).
What do I need to do if I visit an area of Chikungunya transmission?
Reducing your risk of Chikungunya fever involves reducing your risk of being bitten by mosquitoes. Pregnant women, immuno-deprived people and people suffering from a severe chronic illness should consult their physicians prior to the travel in order to assess their risk and get recommendations on personal preventive measures.
All travellers to the countries where Chikungunya Fever is occurring should take the following preventive measures to minimise the exposure to mosquito bites while in the areas:
- Use of anti-mosquito devices (insecticide-treated bed nets, spray, repellents) and wearing long sleeve - long leg clothes, especially during the hours of highest mosquito activity. [For further tips on how to avoid mosquito bites, see the Travel Health section of the HPSC website]
- Mosquito repellent based on a 30% DEET concentration is recommended. Before using repellents, pregnant women and children under the age of 12 years should consult a physician or pharmacist. For newborn children under three months, repellents are not recommended; instead, insecticide-treated bed nets and protective clothing should be used.
- Pregnant women, immunosupressed people and people suffering from a severe chronic illness should consult their doctor prior to the travel in order to assess their risk and get recommendations on personal preventive measures.
Where can I go for further information?
The World Health Organization (WHO) provide this useful factsheet on Chikungunya.
The WHO South-East Asia Region also provides a useful information on Chikungunya.
The Centers for Disease Control and Prevention, US has produced excellent advice on Chikungunya (and all other tropical and exotic diseases).
Last updated: 23 February 2015