Chikungunya

Chikungunya is a viral fever that spreads to people through mosquito bites. The virus, called chikungunya virus, belongs to the Togaviridae family and the alphavirus genus. Aedes mosquitoes, particularly Aedes aegypti and Aedes albopictus, are the main vectors. The same mosquitoes also transmit dengue and Zika, which is why these three diseases are often found in the same regions.

The most common symptoms are sudden fever and severe pain in the joints. The disease name comes from Makonde and means "that which bends up" or "that which breaks you," referring to the posture of patients when their joints ache. The disease is usually not fatal, but joint pain can persist for months or even years after the fever subsides.

Transmission

A mosquito acquires the virus when it bites a person with viraemia—the period of high virus levels in the blood, typically the first few days of infection. After a short period inside the mosquito, the virus can then be transmitted to another person. Aedes mosquitoes usually bite during the day, especially in early morning and late afternoon. They breed in small bodies of standing water: basins, tyres, flower pots, and shallow water containers around houses. The virus does not spread directly from person to person.

Symptoms and disease course

Symptoms typically begin a few days after a mosquito bite. They include high fever that rises suddenly, joint pain affecting both sides of the body (wrists, ankles, feet), headache, muscle pain, fatigue, and sometimes a dark-coloured rash. Most patients recover within a week or two. In some cases, joint pain becomes chronic. Severe disease is more common in the elderly, young children, and those with other conditions such as diabetes or heart and kidney disease.

Testing and treatment

Diagnosis is based on blood tests: direct virus detection (PCR) when illness is recent, or antibody testing when checking later. There is no specific antiviral treatment that kills the virus. Treatment is supportive: rest, abundant fluids and electrolytes, and pain relief and fever-reducing medication. When dengue has not been ruled out, doctors avoid aspirin and NSAIDs, as these can increase the risk of bleeding.

Prevention

The most important prevention is reducing contact between people and mosquitoes: screens, clothing that covers the body, mosquito repellents, and screened accommodation. It is also essential to eliminate standing water around houses where mosquitoes breed. A chikungunya vaccine has been developed in recent years and approved by some countries, but its use and availability are not uniform worldwide.