Introduction

Chikungunya is a self limiting febrile viral disease, which spreads to humans via infected mosquitoes. CHIKV was first isolated from the blood of a febrile patient in Tanzania in 1953, and has since been identified repeatedly in West, Central and Southern Africa and many areas of Asia, and has been cited as the cause of numerous human epidemics in those areas since that time.

There is a risk of importation of CHIKV into new areas by infected travelers due to current large CHIKV epidemics and the world wide distribution of Aedes aegypti.

Causative agent: Chikungunya virus (CHIKV) is a member of the genus Alphavirus, in the family Togaviridae

Transmission: Bitten by the infected Aedes aegypti mosquitoe. Aedes albopictus (the Asian tiger mosquitoe) may also play a role in human transmission in Asia and Africa.

Incubation period:Usually 3 – 7 days

Sign & Symptoms

Fever with aching, painful joints primarily wrist, knee, ankle and small joints of extremities lasting days to months (Polyarthritis is a characteristic features of Chikungunya infection), nausea, vomiting and rash (non-pruritic maculopapular affecting mainly the trunk and limbs).

The rash resolves within 7 – 10 days and is followed by a fine desquamation. Tiredness and fatigue can also last for months.

Cervical lymphadenopathy is also a common sign of Chikungunya infection.

Complication

No deaths have been reported due to Chikungunya.

Treatment

Symptomatic treatment

Advise rest, drink plenty of fluids and take regular painkillers (e.g. Paracetamol or Ibuprofen) to relieve symptoms of fever and aching.

A person with Chikungunya infection should limit their exposure to mosquito bites in order to avoid further spreading the infection. They should stay indoors or under a mosquito net.

No vaccine or specific antiviral treatment for CHIKV is available.

Prevention & Precautions

Vaccination

At present, there is no vaccine to prevent Chikungunya.

Prevention/precautions

• Minimize exposure to bites by modifying activities to avoid exposure to vector bites. Aedes mosquitoe peak biting times are a few hours before dusk and after dawn. Avoid outdoor activity during these periods.
• Avoid mosquito bite by applying mosquito repellent to exposed skin. When using sunscreen or lotions, apply repellants last. Reapply whenever sweat or water has removed it. Active ingredient in a repellent repels but does not kill insects. Repellent that contains DEET (N, N-diethylmetatoluamide) is most reliable and long-lasting type (35% DEET provides protection for 12 hours). DEET formulations as high as 50% are recommended for both adults (including pregnant women) and children >2 months of age. It is toxic when ingested and may cause skin irritation. Permethrin is highly effective both as an insecticide and as a repellent. There is little potential for toxicity from Permethrin-treated clothing.
• Use long sleeved clothes and long pant. Avoid wearing dark colours (attract mosquitoes).
• Close windows or shutters at night when indoors. Use pyrethrum insecticide spray (aerosol insecticides), pyrethroid coils or insecticide impregnated tablets in evening before sleep.
• Avoid strong perfumes, hair sprays or after-shaves (attract mosquitoes)!
• Use air-conditioning or good mosquito net especially treated with Permethrin.

A person with Chikungunya infection should limit their exposure to mosquito bites in order to avoid further spreading the infection. They should stay indoors or under a mosquito net.

References organisation/ support

International Travel & Health, WHO 2006

Control of Communicable Diseases Manual, 18th Edition by David L. Heymann, MD, Editor, 2004

http://travelhealth.co.uk/