Chikungunya Outbreaks

Chikungunya Outbreaks 2025

Chikungunya virus (CHIKV) disease outbreaks have been recorded as early as 1824 in India. As of January 22, 2025, the World Health Organization (WHO) confirmed Chikungunya, a viral illness, and transmissions have occurred frequently in about 110 countries in the past decade in Africa, Asia, and the Region of the Americas. On January 20, 2025, the WHO published a Global Strategic Preparedness, Readiness, and Response Plan for Aedes-borne arboviruses.

The U.S. Centers for Disease Control and Prevention (CDC) lists countries and territories with evidence of chikungunya virus transmission among humans within the last five years. In 2025, the Pan American Health Organization (PAHO) reported 523 Chikungunya cases in Brazil. In 2024, 425,138 CHIKV cases and 236 related fatalities were reported in the Region of the Americas. Between 2013 and 2023, the PAHO reported more than 3.7 million CHIKV cases in the Americas. 

Africa Chikungunya Outbreaks

Chikungunya cases are mainly located in Africa's Sahel region's 33 million population (Senegal, The Gambia, Burkina Faso, and Mali), where ongoing or previous local transmission of CHIKVD occurred. A Review Article published in October 2024 disclosed the incidence of Chikungunya in tropical Africa. The overall pooled prevalence of Chikungunya in East Africa was 20.6% (95% CI: 18.8%–22.5% and I2 = 99.62%). Subgroup analyses revealed Rwanda and Djibouti exhibited high prevalence rates of 63% and 50.4%, respectively, while Kenya and Somalia reported a moderate prevalence of 12.2%. The Republic of Djibouti reported that there were 8 CHIV cases in U.S. armed forces members between 2016 and 2022.

On November 9, 2023, the U.S. CDC published a Level 2—Practice Enhanced Precautions, Travel Health Advisory, regarding chikungunya outbreaks in Burkina Faso. From 2019–2020, a large-scale chikungunya outbreak occurred in the Republic of Djibouti. 

Asia Chikungunya Outbreaks

In 2004, the CHIKV East/Central/South African (ECSA) genotype moved from Africa to the Indian Ocean islands and India, producing a large epidemic in Southeast Asia. As of January 2025, the European CDC reported that India, Pakistan, Thailand, Timor-Leste, the Maldives, Malaysia, Bali, and Myanmar had reported recent CHIKV outbreaks. In 2024, the CDC published an updated Level 2—Practice Enhanced Precautions, Travel Health Advisory regarding chikungunya outbreaks in various Indian states, such as Maharashtra and Telangana. Chikungunya disease was initially reported in India in 1963. As of 2024, every area in India had become endemic to the disease. On January 2, 2025, India's National Center for Vector Borne Diseases Control reported 192,343 CHIKV cases in 2024 and 200,064 in 2023. Pune's National Institute of Virology (NIV) studies patient samples to determine if Chikungunya virus variants (Indian Ocean Lineage) are causing more cases and lingering symptoms in 2024. 

Karachi, Pakistan, experienced a chikungunya outbreak in 2024. The Aga Khan University Hospital says that prevention (vaccination) is the best way to avoid severe complications and fatalities associated with this virus in 2025. As of October 2024, 2.447 CHIKVD cases have been reported in Pakistan.

Carribean Chikungunya Outbreaks

The first documented autochthonous transmission of the chikungunya virus in the Caribbean island of Saint Martin was in 2013. Since 2014, Chikungunya has been detected in Grenada, West Indies. As of October 2024, 8 cases were reported in Barbados. Between 2014 and 2021, there were 221 confirmed chikungunya cases and two deaths in Barbados. Valneva SE's chikungunya vaccine is available at the Virgin Islands Health Department's Community Health Clinics (St. Thomas-St. John District) in 2024.

Central America Chikungunya Outbreaks

On December 31, 2024, 195 Chikungunya cases in Central America were reported in Belize, Guatemala (99), and Costa Rica. The PAHO said Chikungunya has been reported in Mexico since 2014. 

Europe Chikungunya Outbreaks

The geographic expansion of Ae. albopictus mosquitoes to more temperate regions increase the risk of arboviral disease outbreaks in Europe in 2024. As of 2025, the European CDC assessment for CHIKV outbreaks was low. The ECDC says the likelihood of local chikungunya virus transmission in mainland EU/EEA is linked to the importation of the virus by viraemic travelers into receptive areas with established and active, competent mosquitos. Past autochthonous outbreaks of CHIKV in mainland EU/EEA have occurred between June and November. Aedes albopictus is found in most of Europe.

Since its introduction in 2004, the Aedes albopictus mosquito (tiger mosquito) has spread to most of mainland France. In 2024, for the first time, an indigenous (locally acquired) case of Chikungunya was reported in Ile de France (Paris). In addition, 25 travel-related cases were reported as of December 2024. Two autochthonous cases were recorded in the commune of Cannet des Maures in the Var department in 2010, 11 cases in Montpellier in 2014, and 2 cases in the Var Department in 2017.

According to the ECDC Communicable Disease Threats Report 2024, France's Department of La Réunion reported autochthonous CHIKV cases. In 2024, Reunion Island had 138 confirmed CHIKV cases, primarily in Étang-Salé: Sheunon ravine district (70 cases). The last major chikungunya virus disease epidemic in La Réunion was 2005–2006. Although CHIKV is generally transmitted by Ae. aegypti mosquitoes, the outbreak that occurred in La Réunion island was caused by Ae. albopictus, which acted as the primary vector due to the ECSA CHIKV genotype adaptation to this vector, as the E1-A226V, resulted in a dramatic increase in infectivity.

Travel-associated outbreaks led to CHIKV transmission in Italy in 2007. As of November 2024, Italy's National Institute of Health, Epidemiology for Public Health, reported 14 travel-related Chikungunya cases. A study published in December 2024 indicates that without vaccination, a CHIKV outbreak is estimated to infect up to 6.21% (170,762) of Rome's population.

Grenada, Spain, reported CHIKVD cases in September 2024.

Maldives Chikungunya Outbreak

Local authorities reported elevated chikungunya activity in multiple areas of the Maldives, with 389 cases reported in 2024. The U.S. CDC says there has been evidence of CHIKV  transmission in the Maldives within the last five years. A previous significant chikungunya outbreak occurred in 2019 when 1,736 cases were reported. On May 28, 2024, the CDC issued a Level 2—Practice Enhanced Precautions, Travel Health Advisory for the Maldives.

South America Chikungunya Outbreaks

Chikungunya outbreaks have been reported in Brazil since 2014. The highest-risk clusters were initially located in the northeast, dispersed to the central west and coastal areas of São Paulo and Rio de Janeiro (2018–2021), and then increased in the northeast (2019–2021). Brazil's Ministry of Health publishes weekly Arboviruses reports highlighting CHIKV cases.

On January 17, 2025, the PAHO reported 523 CHIKV cases in Brazil in 2025. The Sao Paulo dashboard was updated in 2025. As of the end of 2024, the PAHO reported over 420,139  chikungunya cases and 236 related deaths in Brazil. On October 28, 2024, a study reported that in 2023, during the epidemic in Minas Gerais, there were 890 excess deaths attributed to Chikungunya, translating into a mortality rate of 35.1/100,000 inhabitants. In March 2024, a study conducted at the São José do Rio Preto Medical School in São Paulo State, Brazil, showed that the virus circulated in the city silently for years. An analysis of the blood samples showed that the number of chikungunya cases in proportion to the population rose from 0.35% in 2015 to 2.3% in 2019. In February 2024, The Lancet Infectious Diseases published results from a study in Brazil that concluded Chikungunya virus disease is associated with an increased risk of death for up to 84 days after symptom onset, including deaths from cerebrovascular diseases, ischaemic heart diseases, and diabetes. According to data from the Brazilian Vigilance Health Secretary, the three Brazilian states with the most CHIKV cases were Pernambuco, São Paulo, and Paraíba in 2022. And in 2021, in São Paulo, Brazil's most populous state, cases increased from 468 to 18,156 compared to 2020. 

Chikungunya was first reported in Argentina in 2016. A recent study traced the evolution of the chikungunya virus in Argentina, 2016-2023. In 2024, 768 Chikungunya cases have been reported in Argentina. The PAHO reported 1,746 CHIKV cases in Argentina in 2023.

The first case of Chikungunya in Bolivia was reported in early 2015. As of 2024, over 474 cases had been reported. In 2023, 1,455 cases were reported, with no deaths, representing an 8-fold increase in patients compared to the same period in 2022.

This study focused on seven years after the 2014-2015 CHIKV outbreak in Piedecuesta, Colombia, concluded in October 2024, determine the incidence of post-chikungunya chronic rheumatism (pCHIK-CR) and its impact on quality of life and chronic fatigue in adults. Chronic fatigue prevalence increased from 8.6% in without rheumatic disease patients to 25% in non-inflammatory pain, likely degenerative, and 54.6% in pCHIK-CR cases. 

In 2024, Paraguay reported over 2,700 cases. As of 2023, the PAHO reported 115,000 CHIKV cases in Paraguay. The U.S. CDC Advisory Committee on Immunization Practices workgroup presented an UPDATE AND OBSERVATIONS ON A LARGE CHIKUNGUNYA OUTBREAK IN PARAGUAY on June 22, 2023. From October 2022 to June 3, 2023, 167,239 chikungunya cases were reported. The CDC Health Alert Network issued CDCHAN-00487 on March 2, 2023,  confirming that the Ministry of Health in Paragusaidted 71,478 suspected chikungunya cases in Paraguay since the outbreak began in October 202. Currently, the East/Central/South African (ECSA) chikungunya genotype is circulating; it was first identified in 2018 during an outbreak in the Amambay department and was again identified in samples from 2022 in the Metropolitan Area of Asunción. As a result, an outbreak in Paraguay and surrounding countries is possible. In addition, the CDC reissued a Watch - Level 1, Practice Usual Precautions notice on April 6, 2023, confirming an outbreak of Chikungunya in Paraguay's Asunción metropolitan area.

United Kingdom Chikungunya 2024

As of December 2024, travel-associated chikungunya cases have been reported in the U.K. Between January and June 2024, 24 cases were reported: 23 in England (10 in London), one in Wales, and zero in Northern Ireland. This represents a 71% increase compared to the same period in 2023, which saw 14 cases. A Travel Health Pro and International Health Regulations team reported in the Clinical and Emerging Infections Directorate, U.K. Health Security Agency (UKHSA) summarises Chikungunya cases in England, Wales, and Northern Ireland between 2015 and 2022. In 2023, laboratories in England have a statutory duty to notify the UKHSA of identifying the chikungunya virus.

United States Chikungunya Cases 2024

As of December 2024 (Week 47), the U.S. Centers for Disease Control and Prevention (CDC) reported 173 chikungunya cases in Territories and non-U.S. residents in 2024, led by Massachusetts (20), Texas (21), California, Colorado, Illinois, and New York. From 2006 to 2023, 4,590 travel-related CHIKV cases were reported in the U.S., in areas such as Florida and Puerto Rico. 

Chikungunya Vaccines

As of January 2025, the U.S. FDA had authorized one chikungunya vaccine. 

Chikungunya Disease

Chikungunya is a viral disease transmitted to humans through the bites of mosquitoes infected with the chikungunya virus (CHIKV), according to the U.S. Centers for Disease Control and Prevention (CDC) Yellow Book 2024. In 2013, the CHIKV Asian genotype drove an outbreak in the Americas.

In September 2024, an Original Article reported even after a year, Chikungunya fever-affected people experience damage to their physical and mental health, positive screening for depression risk was 13.5 times more likely in chronically affected, and patients with chronic chikungunya fever 76 times higher risk of walking impairments. In April 2024, the journal Cell Host & Microbe published results from a study, Pathophysiology of chikungunya virus infection associated with fatal outcomes, that suggests the chikungunya virus crosses the blood-brain barrier, contributing to central nervous system infections.

The Lancet Infectious Diseases published results from a study in February 2024 investigating the risk of death in people infected with Chikungunya two years after the first symptoms of the disease. Between 2015 and 2018 in Brazil, Chikungunya virus disease was associated with an increased risk of death for up to 84 days after symptom onset. The Lancet Infectious Diseases researchers published a study on February 8, 2024, the found Chikungunya virus disease is associated with an increased risk of death for up to 84 days after symptom onset, including deaths from cerebrovascular diseases, ischaemic heart diseases, and diabetes. Data from 2015 to 2018 in Brazil revealed the incidence rate ratio (IRR) of death within seven days of chikungunya symptom onset was 8.40 (95% CI 4·83–20·09) as compared with the unexposed group and decreased to 2.26 in 57–84 days, and 1,05 at 85–168 days, with IRR close to 1 and wide CI in the subsequent periods.

Chikungunya Carrying Mosquitoes

Over thousands of years, mosquito bites have caused more human suffering than any other organism. People can become infected with the chikungunya virus when mosquitoes feed and bite on another infected person. During the first few days of illness, people infected with the virus have high enough levels of virus in their blood (viremia) to transmit the virus to mosquitoes. Recent studies published by the Royal Society and The Lancet indicate that disease-carrying mosquitoes are expanding their range by an average of 6.5 meters of elevation and have moved polewards by 4.7 km annually.