What is chikungunya? A guide to the mosquito-borne virus

Chikungunya is caused by the chikungunya virus (CHIKV) that belongs to the Togaviridae family (a part of the Alphavirus genus). It is spread through the bites of Aedes mosquitoes, specifically Aedes aegypti and Aedes albopictus.

It’s a small spherical virus that resembles a little ball wrapped in a fatty layer borrowed from the cells it infects. It has special spike-like proteins on the surface that help it attach to human cells. Once inside a human cell, the virus hijacks the cell to replicate. 

The chikungunya virus causes severe joint pain by infecting synovial tissue (the lining in joints), leading to inflammation and swelling. This viral infection is also known as “arthritis fever” because it causes joint inflammation and its symptoms resemble those of rheumatoid arthritis.

The story of chikungunya (CHIKV) begins in 1952 on the Makonde Plateau, along the border between modern-day Tanzania and Mozambique. It was here that scientists first isolated the virus during an outbreak of fever.

The local name, “chikungunya,” means “bent up,” and it describes the stooped posture of people suffering from intense joint pain.

For about 50 years, the virus caused sporadic, relatively small outbreaks in Africa and Asia. However, the 21st century saw a dramatic shift.

Chikungunya virus is now found in 119 countries across Africa, Asia, Europe, and the Americas, according to the WHO. The virus thrives in tropical and subtropical regions where the Aedes mosquitoes that carry it are most common.

Global hotspots

Major outbreaks have occurred in:

• The Indian Ocean: Islands like Réunion, Mauritius, and the Seychelles have experienced large-scale epidemics
• South and Southeast Asia: India, Thailand, Indonesia, and Malaysia have reported millions of cases
• The Americas: Since its introduction in 2013, the virus has become widespread in the Caribbean, Central America, and South America, particularly in countries like Brazil and Colombia

Chikungunya is spreading

The threat is no longer confined to the tropics. Climate change and global travel are helping the mosquitoes that spread Chikungunya expand their territory. 

Local transmission has already been reported in parts of Europe, including France and Italy, and the mosquitoes are present in the southern United States. Scientists warn that warming temperatures and climate change are making more temperate regions hospitable for these insects, increasing the risk of future outbreaks.

Who is most at risk?

Anyone living in or traveling to an area with Chikungunya is at risk. 

However, certain groups are at greater risk of severe disease, including:

• Newborns exposed during birth
• Older adults (especially those over 65)
• People with underlying medical conditions such as high blood pressure, diabetes, or heart disease

Notable outbreaks

Globally, there are about 220,000 chikungunya cases reported, although the case count may be higher. Here are some notable chikungunya outbreaks and epidemics worldwide:

• 2005–2006: La Réunion (France): 266,000 cases, 254 deaths. This outbreak affected almost a third of the entire population
• 2006: India: 1.39 million cases (2006-2007: India: 1.5 million cases)

• 2013 – 2014: Americas (Caribbean): 1.1 million cases, 178 deaths

• 2014: Dominican Republic: 539,099 cases, 6 deaths

• 2016: Brazil: 352,810 cases, 120 deaths

• 2022: Brazil: 229,683 cases, 58 deaths

• 2022: India: 69,398 cases 

• 2024: Brazil: 407,250 cases, 203 deaths
• 2025 (as of June 2025): Brazil: 141,436 cases, Asia: 33,000+ cases (India, Sri Lanka, Pakistan)

GIDEON provides detailed lists of chikungunya outbreaks, cross-border notes, prevalence and seroprevalence surveys, clinical details, and much more. GIDEON is a comprehensive infectious disease database.

Chikungunya does not spread from person to person. It is spread through infected mosquitoes.

However, in rare cases, the virus can be transmitted from a mother to her newborn around the time of birth if the mother has the virus in her blood. Blood-borne transmission through transfusions is theoretically possible but extremely rare.

The role of Aedes mosquitoes

The primary culprits spreading chikungunya are two species of mosquito: Aedes aegypti (the yellow fever mosquito) and Aedes albopictus (the Asian tiger mosquito). These are the same mosquitoes that transmit dengue and Zika viruses.

The life cycle begins when a mosquito bites a person who is already infected with chikungunya. The mosquito picks up the virus, and after a few days, it can transmit the virus to the next person it bites.

These mosquitoes are aggressive daytime biters and often live in and around human dwellings, using small containers of standing water to lay their eggs.

The symptoms of Chikungunya are often severe and appear in two distinct phases for many patients.

The acute phase: more than just a fever

Symptoms typically begin 3 to 7 days after a mosquito bite and often start suddenly. The most common signs include:

• High fever: Often reaching 102-104°F (39-40°C)
• Severe joint pain (arthralgia): This is the hallmark symptom. The pain is often debilitating, affecting multiple joints, especially in the hands, wrists, ankles, and feet.
• Joint swelling
• Headache
• Muscle pain
• Rash: A maculopapular rash (flat red area with small bumps) often appears a few days into the illness

Many people feel better within a week or two. However, for some people with chikungunya, the ordeal is far from over.

The chronic phase: the joint pain can last for years

Unlike many viral illnesses, chikungunya is notorious for its long-term effects. Up to 50% of people infected with chikungunya develop chronic inflammatory arthritis that can persist for months or even years after the initial infection.

This chronic condition mimics rheumatoid arthritis, causing persistent joint pain, stiffness, and swelling. Researchers believe this happens because the virus may persist in joint tissues, triggering a continuous and damaging immune response.

This lingering inflammation can severely impact a person’s quality of life, making it difficult to work, perform daily tasks, or even walk without pain.

Chikungunya’s symptoms often overlap with other mosquito-borne illnesses, so a proper diagnosis is necessary to get treated.

Differentiating from dengue and Zika

Early chikungunya can look very similar to dengue and Zika. All three can cause fever, rash, and body aches. However, the joint pain in chikungunya is typically much more severe and debilitating than in dengue or Zika. It is possible to be infected with more than one of these viruses at the same time.

Laboratory tests

A definitive diagnosis requires laboratory testing. Healthcare providers can use blood tests to look for the virus or the body’s response to it.

• RT-PCR (Reverse-transcriptase polymerase chain reaction): This test detects the virus’s genetic material (RNA) and is most effective in the first week of illness.
• Serological Tests (ELISA): These tests detect antibodies (IgM and IgG) that the immune system produces to fight the virus. IgM antibodies appear after the first week and indicate a recent infection.

There is no cure for Chikungunya, so treatment is focused on managing symptoms and improving quality of life, especially for those with chronic arthritis.

Managing acute symptoms

For the initial illness, treatment is supportive:

• Rest: Get plenty of sleep and rest
• Fluids: Drink lots of water to prevent dehydration
• Pain and fever relief: Medications like acetaminophen (paracetamol) can help reduce fever and pain

Important: Non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen should be used with caution and typically only after a doctor has ruled out dengue, as these drugs can increase the risk of bleeding in dengue patients.

Addressing chronic arthritis

Managing post-Chikungunya chronic arthritis is more complex and often requires a rheumatologist. 

Treatment aims to reduce inflammation and preserve joint function. 

Options may include:

• NSAIDs: For ongoing pain and inflammation
• Corticosteroids: To control severe inflammation
• Disease-modifying antirheumatic drugs (DMARDs): For persistent, severe arthritis, medications like methotrexate may be prescribed to suppress the overactive immune response

Prevention and vector control are still the most effective strategies to battle chikungunya, but with the approval of new vaccines, there is hope on the horizon.

Chikungunya vaccines

In a major breakthrough, the U.S. Food and Drug Administration (FDA) approved the world’s first Chikungunya vaccine, Ixchiq, in November 2023. Ixchiq is approved for individuals 18 years and older who are at increased risk of exposure to the virus. 

In February 2025, the FDA approved Vimkunya, manufactured by Bavarian Nordic, for adults and teens 12 years and older. 

This represents a critical new tool in protecting travelers, laboratory workers, and people living in endemic areas.

Mosquito control measures

Until the vaccines become widely available, personal protection against mosquito bites remains the main way to curb chikungunya infections. Here are some ways to protect against mosquitoes:

• Use insect repellent: Choose an EPA-registered repellent containing DEET, picaridin, IR3535, or oil of lemon eucalyptus
• Cover up: Wear long-sleeved shirts and long pants
• Keep mosquitoes out: Use screens on windows and doors, and sleep under a mosquito net if you are in an area with high exposure
• Eliminate standing water: Mosquitoes breed in stagnant water. Regularly empty, clean, or cover items that hold water, such as tires, buckets, planters, and birdbaths

Chikungunya is a serious global health threat. It can cause long-lasting, debilitating joint pain. While it had previously been limited to a few regions, it is fast spreading to other areas of the world.

Its rapid spread across continents serves as a stark reminder of how interconnected our world is, the effects of climate change, and how diseases can cross borders rapidly.

While the primary defense has long been mosquito control, the development and approval of two chikungunya vaccines is a gamechanger. By combining vaccination with proven prevention strategies, we can better protect communities and travelers from the painful grip of this “bending” disease.

What is the main cause of chikungunya?

The main cause of chikungunya is the chikungunya virus (CHIKV). It is an arbovirus, meaning it is transmitted to people through the bite of an infected arthropod, in this case, the Aedes aegypti and Aedes albopictus mosquitoes.

How long does chikungunya arthritis last?

Joint pain after chikungunya varies from person to person. Some people recover within a few weeks, while others experience chronic pain that can last months or even years. Studies show that many patients still have joint pain 1-3 years after infection.

What is the best treatment for chikungunya?

There is no specific antiviral cure. The best treatment for the acute phase is supportive care: rest, hydration, and pain/fever reducers like acetaminophen. For the chronic arthritis that follows, treatment is more specialized and may include NSAIDs, corticosteroids, or immunosuppressive drugs like methotrexate, often managed by a rheumatologist.

Is chikungunya worse than dengue?

“Worse” is subjective and depends on the specific case. Dengue can be more life-threatening in its severe forms (Dengue Hemorrhagic Fever or Dengue Shock Syndrome), which can cause fatal bleeding and organ failure. Chikungunya is rarely fatal, but its hallmark is severe, long-lasting, and debilitating joint pain that can drastically reduce a person’s quality of life for years, a feature much less common with dengue.

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