Overview

Chikungunya is a mosquito-borne viral disease that causes sudden fever and severe joint pain. The name “chikungunya” comes from the Kimakonde language of southern Tanzania and northern Mozambique and means “that which bends up” or “to become contorted.” The term describes the stooped posture adopted by many sufferers because of intense joint pain. 

The disease was first recognized during an outbreak in southern Tanzania in 1952–1953. Clinically it is frequently confused with dengue fever and Zika virus infection as all three are transmitted by the same mosquitoes and often occur in the same regions and  initially with similar symptoms. 

Although chikungunya is rarely fatal, it causes considerable illness, disability, and economic burden. Many patients recover within several weeks, but a significant proportion continue to experience joint pain and stiffness for months or even years, affecting their quality of life and ability to work. 

Transmission

Chikungunya is a mosquito-borne viral disease.

Nature of the disease

The disease is characterized by sudden onset of fever, severe joint pain, headache, muscle aches, rash, and fatigue. While the acute illness usually resolves within one to two weeks, many patients experience prolonged or recurrent joint pain that can persist for months or even years, making chikungunya a major cause of long-term disability despite its low mortality rate. 

Geographical distribution

Chikungunya is found throughout tropical and subtropical regions of the world. During the past two decades, its geographical range has expanded dramatically due to increasing global travel, urbanization, climate change, and the spread of mosquito vectors. The disease is endemic in much of Sub-Saharan Africa, South and Southeast Asia, the Indian subcontinent, the Pacific Islands, Central America, South America and the Caribbean. 

Europe has experienced several locally transmitted outbreaks, particularly in Italy and southern France, where the mosquito vector has become established. In the United States, locally acquired infections have occurred in Florida and Texas, although most cases are imported by travellers. 

Because infected travellers can introduce the virus into new areas where competent mosquitoes exist, chikungunya remains a significant global public health concern. 

Risk for travellers

Age Profile 

People of all ages are susceptible. The highest infection rates occur in adults because of greater exposure to mosquitoes. However newborn babies infected around birth may develop severe disease. In children the joint pain tends to be less severe than in adults. 

Typical Symptoms 

These can be quite variable (including those without symptoms) but include sudden high fever, severe joint and muscle pain and pronounced fatigue. Many adults develop prolonged arthritis lasting months. 

High-Risk Groups 

Greater risk of severe illness occurs in elderly people, during pregnancy, newborn infants, those with diabetes, heart disease or individuals with chronic kidney disease 

Incubation Period 

The incubation period is usually 3–7 days but this can vary between 1–12 days. Symptoms usually begin with sudden onset of high fever, severe joint pain, chills, headache, rash and muscle pain. The joint pain commonly affects the wrists, fingers, ankles, knees and feet. Strangely the pain is usually symmetrical. Most patients remain febrile for 2–4 days.Approximately 30–50% of patients experience persistent arthritis or joint stiffness which can last for months to years. Some develop inflammatory arthritis resembling rheumatoid arthritis. 

Mortality 

Chikungunya has a very low mortality rate. The overall case fatality rate is generally less than 1%. However although death is uncommon, severe complications include encephalitis, Guillain–Barré syndrome and meningitis along with myocarditis and heart failure. Large epidemics occasionally result in increased mortality because frail patients develop complications of prolonged illness. However the major burden of chikungunya is disability rather than death. 

Diagnosis 

Clinical suspicion is essential, particularly during outbreaks. The disease resembles dengue, Zika, malaria, leptospirosis, and influenza. 

Laboratory Diagnosis 

Reverse transcriptase polymerase chain reaction (RT-PCR) is the preferred test during the first week as it is highly sensitive and highly specific and provides a rapid diagnosis. However in many cases the diagnosis is made on finding antibodies circulating in the patient’s serum. 

Treatment 

There is no specific antiviral treatment currently licensed for chikungunya and management is supportive. Patients should receive adequate fluids and paracetamol for fever. Non-steroidal anti-inflammatory drugs (NSAIDs) should generally be avoided until dengue has been excluded because dengue increases the risk of bleeding. 

Protection 

Mosquito avoidance remains the cornerstone of prevention. 

Travel Advice 

Travellers to endemic countries should remain vigilant throughout daylight hours, since Aedes mosquitoes are primarily daytime biters. Individuals returning home (to regions where these mosquitoes are found) while still febrile should avoid mosquito bites to reduce the possibility of introducing the virus into local mosquito populations. 

Vaccination 

For many years no vaccine was available. However, this changed in 2023 with the approval of the first chikungunya vaccine. 

The first licensed vaccine is a live-attenuated vaccine, approved in several countries for adults at increased risk of exposure. It is designed to provide protection against symptomatic chikungunya infection after a single dose. Because it is a live vaccine, it is generally not recommended for people with significant immunosuppression, and recommendations for older adults have been updated in some countries following reviews of rare serious adverse events. Vaccination decisions should therefore follow current national guidance and individual risk assessment. 

Vaccination should be considered for travellers with prolonged or repeated exposure to endemic regions as well as those living in regions with outbreaks, where national recommendations support its use. 

Summary 

Chikungunya is an important mosquito-borne viral disease caused by the chikungunya virus, an alphavirus transmitted primarily by Aedes aegypti and Aedes albopictus mosquitoes. Since its identification in Tanzania in the early 1950s, it has spread widely across Africa, Asia, Europe, the Americas, and the Pacific, aided by global travel, urbanization, and the expansion of mosquito vectors. 

The disease is characterized by sudden onset of fever, severe joint pain, headache, muscle aches, rash, and fatigue. While the acute illness usually resolves within one to two weeks, many patients experience prolonged or recurrent joint pain that can persist for months or even years, making chikungunya a major cause of long-term disability despite its low mortality rate.

Diagnosis relies on clinical suspicion supported by laboratory testing, particularly RT-PCR during the early phase of illness and serological testing later in the disease course. There is currently no specific antiviral therapy, so treatment focuses on symptom relief, hydration, pain management, and rehabilitation for persistent arthritis. 

Prevention remains centred on avoiding mosquito bites through the use of repellents, protective clothing, environmental mosquito control, and community public health measures. The introduction of licensed vaccines represents an important advance in the prevention of chikungunya, particularly for individuals at increased risk of exposure, although vaccination policies continue to evolve. Combined with effective surveillance, vector control, and public education, these measures provide the best strategy for reducing the global burden of this increasingly important arboviral disease.