An infectious disease

Chikungunya is an infectious disease caused by an arbovirus—"arthropod-borne viruses" are viruses transmitted by blood-feeding arthropods (notably mosquitoes, sandflies, and ticks). They belong to three main families: the Flaviviridae, the Togaviridae, and the Bunyaviridae." data-tooltip-title="Arboviruses (arthropod-borne viruses) are viruses transmitted by blood-feeding arthropods (notably mosquitoes, sandflies, and ticks). They belong to three main families: the Flaviviridae, the Togaviridae, and the Bunyaviridae." data-tooltip-content="" data-tooltip-placeholder-is-selection="true" data-tooltip-placeholder-is-selection-text="arbovirus" data-tooltip-data="[{"tooltipTitle":"Arboviruses « arthropod-borne viruses » are viruses%transmitted by blood-feeding arthropods (mosquitoes, sandflies, and ticks, among others). They belong to three main families, the Flaviviridae, the Togaviridae, and the Bunyaviridae.","tooltipContent":"","placeholderIsSelection":"true","placeholderIsSelectionText":"arbovirus"}]">arbovirus: the chikungunya virus. It belongs to the Togaviridae family (genus Alphavirus) and was first isolated in Uganda in 1953 during an epidemic in East Africa. The name “chikungunya” comes from the Makonde language and means “the man who walks bent over.” The disease typically presents with fever and joint pain, which usually resolve spontaneously after a few days

This virus is transmitted from person to person primarily through the bites of mosquitoes of the genus Aedes, mainly Aedes aegypti and Aedes albopictus (also known as the tiger mosquito). 

Several modes of chikungunya transmission

Vector-borne transmission

The chikungunya virus is primarily transmitted by blood-feeding arthropods (which include insects and mites) that transmit an infectious agent (virus, bacterium, parasite) from one vertebrate to another" data-tooltip-title="blood-feeding arthropods (which include insects and mites) that transmit an infectious agent (virus, bacteria, parasite) from one vertebrate to another" data-tooltip-content="" data-tooltip-placeholder-is-selection="true" data-tooltip-placeholder-is-selection-text="vectors" data-tooltip-data="[{"tooltipTitle":"arthropod (including insects and mites) hematophagous (feeding on blood) that transmits an infectious agent (virus, bacteria, parasite) from one vertebrate to another","tooltipContent":"","placeholderIsSelection":"true","placeholderIsSelectionText":"vectors"}]">vectors. For this virus, the vectors are mosquitoes of the genus Aedes, primarily Aedes albopictus (also known as the tiger mosquito) and Aedes aegypti. 
Chikungunya is an infection that is most prevalent in tropical and intertropical regions where the vectors Aedes aegypti and Aedes albopictus are present. In France, Aedes aegypti is found in the French West Indies, French Guiana, and Mayotte, while Aedes albopictus is found on the island of Réunion. Aedes albopictus is also present in temperate regions, particularly in Europe. In mainland France, by 2026, it had become established in 83 departments.

These Aedes mosquitoes primarily breed in urban areas and do not travel far during their lifetimes. Females lay their eggs in sites where standing water is necessary for larval development: rainwater collectors, vases, saucers, used tires, poorly maintained gutters, various types of debris capable of holding stagnant water, as well as tree hollows and certain plants that can trap water (bamboo, bromeliads, etc.). Artificial breeding sites—that is, those created by humans—are the primary egg-laying sites for these mosquitoes.

Aedes mosquito bites occur mainly during the day, with peak activity at dawn and dusk. When a mosquito bites an infected person at a time when the virus is present in their blood." data-tooltip-title="time when the virus is present in their blood." data-tooltip-content="" data-tooltip-placeholder-is-selection="true" data-tooltip-placeholder-is-selection-text="viremic phase" data-tooltip-data="[{"tooltipTitle":"the time when the virus is present in their blood.","tooltipContent":"","placeholderIsSelection":"true","placeholderIsSelectionText":"viremic phase"}]">viremic phase, the mosquito picks up the virus from this person’s blood. The virus then multiplies within the mosquito for approximately 5 to 7 days, a period known as the extrinsic phase. At the end of this extrinsic phase, the mosquito can transmit the virus and infect a new person.
For chikungunya, this refers to the time when the virus is present in the mosquito’s blood." data-tooltip-title="the time when the virus is present in the mosquito’s blood." data-tooltip-content="" data-tooltip-placeholder-is-selection="true" data-tooltip-placeholder-is-selection-text="viremic phase" data-tooltip-data="[{"tooltipTitle":"the time when the virus is present in their blood.","tooltipContent":"","placeholderIsSelection":"true","placeholderIsSelectionText":"viremic phase"}]">The viremic phase begins approximately 1 to 2 days before the onset of clinical signs and lasts up to 7 days after that.

Transmission via products of human origin

During the viremic phase, the virus is present in the blood and certain tissues. Transmission of the Chikungunya virus through products of human origin (blood transfusion, organ or cell transplantation) is considered possible.

Other modes of transmission

A few cases of mother-to-fetus transmission (during the second trimester of pregnancy) and perinatal transmission have been documented

Symptoms and complications

In approximately 10 to 40% of cases, Chikungunya is asymptomatic (the percentage varies depending on the outbreak). 
For 60% to 90% of people infected with the virus, symptoms develop after an incubation period averaging 3 to 7 days (ranging from 1 to 12 days). Typical symptoms include:

• A sudden onset of high fever
• Joint pain, which can be severe, primarily affecting the small joints of the extremities (wrists, ankles, fingers)
• Muscle pain
• Headaches
• A maculopapular rash

The course of the disease is usually favorable after about ten days, with no lasting effects. However, chikungunya can progress to a chronic phase characterized by persistent joint pain. This pain can occur in 30 to 40% of patients and last for several months, or even several years in some patients. 

Diagnosis

Chikungunya virus infection is diagnosed using direct methods (detection of the virus by culture or of its genome by PCR) or indirect methods (detection of antibodies by serology).

The diagnostic strategy for the chikungunya virus is as follows:

• Up to 5 days after the onset of symptoms (D5): RT-PCR
• Between D5 and D7: RT-PCR and serology
• After Day 7: serology only (IgG and IgM) with a second confirmatory sample taken no earlier than 10 days after the first sample

Therefore, it is essential to accurately identify the date of symptom onset in order to select the appropriate tests. 

Early testing (up to Day 7) using RT-PCR should be prioritized due to its higher specificity compared to serology. IgM antibodies can be detected as early as the fifth day after the onset of clinical signs and persist for an average of 2 to 3 months. IgG antibodies appear a few days after IgM and persist for life.

The detection of IgM must always be followed by a second sample for confirmation, taken at least 10 days after the first. A diagnosis of chikungunya will be confirmed if IgG is detected in the second sample, or if there is an increasing IgG titer (generally at least four times higher than in the first blood sample).

Blood samples can be collected by any clinical laboratory. Each sample must be accompanied by a clinical information form. Laboratory
confirmation of chikungunya is particularly important in France’s overseas departments and territories and in mainland France where the vector (Aedes albopictus or Aedes aegypti) is established.

Prevention

Prevention relies on both individual and community-wide actions.

Individual Prevention

Individual prevention relies on measures to protect against mosquito bites: repellents in spray or cream form, long clothing, and mosquito nets. This protection is particularly necessary during the day. Aedes vector mosquitoes primarily bite during the day outdoors, with peak activity during the coolest hours of the day—that is, at the beginning and end of the day. 

Two vaccines have recently received European marketing authorization: 

• the IXCHIQ vaccine from Valneva;
• and the VIMKUNYA vaccine from Bavarian Nordic.

In 2026, given the active circulation of the chikungunya virus in Mayotte and French Guiana—with a risk of the situation escalating into an epidemic—the French National Authority for Health (HAS) recommended, in its opinions dated April 9 and 24, 2026, the use of the VIMKUNYA vaccine:

• for people aged 65 and older (with or without comorbidities);
• for people aged 18 to 64 with comorbidities.

The VIMKUNYA vaccine may be offered to other populations, taking into account the documented duration of protection, which is limited to six months, and the lack of data in immunocompromised individuals. It is not recommended for pregnant or breastfeeding women due to a lack of data.

The HAS states that the IXCHIQ vaccine may be offered to individuals aged 18 to 64 following a thorough review of the potential benefits and risks; it maintains its suspension for individuals aged 65 and older due to pharmacovigilance signals. The IXCHIQ vaccine is not recommended for pregnant or breastfeeding women and is contraindicated for immunocompromised individuals.

The HCSP has been asked to issue recommendations on chikungunya vaccination for travelers; the 2026 recommendations are currently being developed.

Learn more:

• Opinion No. 2026.0022/AC/SESPEV of April 9, 2026, from the High Health Authority’s panel regarding the IXCHIQ and VIMKUNYA vaccines in the context of the re-emergence of chikungunya in French Guiana
• Opinion No. 2026.0027/AC/SESPEV dated April 24, 2026, issued by the College of the French National Authority for Health (HAS) regarding the use of the IXCHIQ and VIMKUNYA vaccines in the context of active circulation of the chikungunya virus with a risk of an epidemic developing in the Indian Ocean
• Information on the IXCHIQ vaccine
• Information on the VIMKUNYA vaccine 
• Chikungunya Vaccination | vaccination-info-service.fr
• Health Recommendations for Travelers | High Council for Public Health