Chikungunya outbreaks: Why India is at the epicentre of a global health threat

India could experience the biggest long-term impacts of chikungunya, potentially putting over 51 lakh people at risk every year, a global modelling study published in BMJ Global Health. According to the research led by the London School of Hygiene and Tropical Medicine, chronic health impacts will be the biggest concern- with evidence suggesting that nearly 50 per cent of affected individuals could experience long-term disability. 

Titled “Global, regional and national burden of chikungunya: force of infection mapping and spatial modelling study,” the study used advanced machine learning models to estimate that over 51 lakh Indians could be affected annually. It positions India as the country most likely to face the highest long-term burden of chikungunya, followed by Brazil and Indonesia. Together, India and Brazil account for 48 per cent of the global health impact of the mosquito-borne disease. 

Despite the magnitude of the problem there is “no specific antiviral treatment for chikungunya virus infections but antipyretic and analgesic medications (such as paracetamol) for fever and pain can be used to alleviate these symptoms,” as stated by the World Health Organization (WHO). 

What is Chikungunya? 

Chikungunya is a mosquito-borne viral disease caused by the chikungunya virus (CHIKV), an RNA virus belonging to the alphavirus genus of the Togaviridae family. The name comes from the Kimakonde language spoken in parts of Tanzania and Mozambique and means “that which bends up”, describing the posture of sufferers due to severe joint pain.  

The virus was first identified during an outbreak in Tanzania in 1952 and later spread across Africa and Asia, including India, which reported its first major outbreak in the 1970s. Since the early 2000s, chikungunya has expanded rapidly across continents, driven by climate shifts and viral mutations that allow easier transmission by the Aedes albopictus mosquito. According to official agencies, the disease “re-emerged” in India in 2006, and has since spread to almost all states. 

The infection spreads through bites of infected female Aedes aegypti and Aedes albopictus mosquitoes, the same species that transmit dengue and Zika viruses. These mosquitoes breed in stagnant water found in domestic containers, flower pots, and discarded tyres. They are most active during daylight hours. When an infected mosquito bites a healthy person, the virus enters the bloodstream, and symptoms appear within two to twelve days. 

Chikungunya usually begins with a sudden high fever and severe joint pain that can immobilise the person. Other symptoms include swelling in the joints, muscle pain, fatigue, headache, rashes, and nausea. Most patients recover within weeks, but joint pain may persist for months or even years. Complications are uncommon but can affect the eyes, heart, or nervous system, especially in infants, the elderly, and people with pre-existing health conditions. 

Diagnosis is confirmed through laboratory tests, either by detecting the virus using RT-PCR during the first week of infection or through antibody testing later. There is no specific antiviral treatment, so management focuses on relieving symptoms. Doctors recommend rest, hydration, and the use of paracetamol or acetaminophen for fever and pain. Anti-inflammatory drugs like ibuprofen are prescribed only after dengue is ruled out. 

“In November 2023, the US Food and Drug Administration approved Ixchiq, the world’s first chikungunya vaccine developed by Valneva for adults aged 18 and over, and multiple chikungunya vaccine candidates are in development. The Ixchiq vaccine was also approved by the European Medicines Agency in May 2024 and Health Canada in June 2024. While this vaccine is initially targeted at travellers from high-income countries, Coalition for Epidemic Preparedness Innovations is accelerating efforts to make the vaccine accessible in endemic regions,” as per the BMJ study.  

Global scale of the threat 

The BMJ Global Health study estimated that chikungunya may cause an average of 1.44 crore infections annually across 103 countries. South Asia alone would account for 64 lakh of these cases, followed by Latin America, East Asia, and Sub-Saharan Africa.  

In a high-risk scenario, the global infection count could rise to 3.49 crore per year, with South Asia carrying the largest share at around 1.6 crore infections. 

The study also found that chikungunya contributes nearly 23 lakh disability-adjusted life years (DALYs) annually, with the chronic phase marked by lingering joint pain and arthritis responsible for more than half of the total disease burden. Adults between 40 and 60 years of age are the most affected, while children under 10 and older adults above 80 are particularly vulnerable to complications and death. 

Why is India at the highest risk? 

According to the analysis, India and Brazil together would account for nearly half of chikungunya’s global health burden, with India alone potentially witnessing over 1.2 crore infections annually in the worst-case scenario. The chronic phase of the disease, marked by persistent joint pain and rheumatic arthritis, constitutes more than half of this burden, particularly affecting adults between the ages of 40 and 60. 

Researchers attribute the rising cases to multiple factors, stating that “globalisation facilitates the spread of mosquito vectors and infected individuals, while climate change impacts various climatic factors like precipitation and temperature, altering mosquito traits such as the extrinsic incubation period and thereby increasing transmission risks in non-endemic regions.” 

Interestingly, the study highlights that the high transmission risk is not confined to tropical regions. Machine learning models revealed that parts of Africa, Latin America, Asia, and even regions beyond the tropics could face future outbreaks, driven by factors such as climate change, increased global travel, and expanding mosquito habitats. 

Data from India’s National Vector Borne Disease Control Programme (NVBDCP) further underscores the concern. Chikungunya cases have been rising in the country— from 57,813 suspected cases and 9,756 confirmed cases in 2018, to 2.4 lakh suspected cases and 17,930 confirmed cases in 2024. This year, as of August, the country has already reported 1,08,379 suspected cases of chikungunya and 4,995 confirmed cases.  

On the vaccine front, Bharat Biotech’s chikungunya vaccine candidate, BBV87, has shown promising progress. After successfully completing preclinical and Phase I trials in India, the vaccine is now undergoing Phase II/III evaluation. As of September 2025, it has been cleared to enter Phase III trials in the country. 

Is there a solution?  

According to the National Vector Borne Disease Control Programme (NVBDCP), the Government of India has taken several measures to prevent and control dengue and chikungunya across the country. The programme outlines that the Centre has “developed guidelines and operational manuals for technical guidance to the States and other stakeholders for effective implementation of the programme” and has “established Sentinel Surveillance Hospitals with laboratory support for augmentation of diagnostic facility for Dengue in endemic State(s) in 2007 which has been increased to 805 in 2023.” These hospitals are linked with 17 Apex Referral Laboratories equipped with advanced diagnostic facilities for backup support. 

The NVBDCP further explains that ensuring the functional diagnostic facilities and availability of test kits lies with the respective State Programme Officers, while “IgM MAC ELISA test kits are provided through the National Institute of Virology (NIV), Pune, to the identified Sentinel Surveillance Hospitals on receipt of requirement from the respective states. Cost is borne by the Government of India.”  

Every year, the NCVBDC prepares tentative allocations of these test kits based on the previous year’s epidemiological trends and maintains buffer stocks to address any emergency outbreaks. To strengthen preparedness, the programme conducts regular training for managers on the implementation of national guidelines and outbreak response. It also “monitors the disease situation for detection of any impending outbreak at an initial stage and to contain further spread by timely implementation of preventive measures.” Advisories are issued to states to ensure readiness and response to potential surges in cases. Under the National Health Mission, budgetary support is also provided to States and Union Territories to aid dengue and chikungunya control activities. 

When it comes to treatment and management, the NVBDCP recommends following the Clinical Management of Chikungunya Fever – 2016 guidelines. These guidelines emphasise that “there is no antiviral drug against CHKV” and that “most of the signs and symptoms are self-limiting.” The treatment, therefore, remains largely symptomatic, focusing on supportive care, adequate rest, and nutrition. Analgesics, antipyretics, and fluid supplementation are key components in managing the illness. According to the document, “supportive care with rest is indicated during the acute joint symptoms. Movement and mild exercise tend to improve stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms.”  

The guidelines also detail home-based care measures for patients, such as ensuring adequate hydration, taking paracetamol (not exceeding 3 grams per day), using antacids to counter gastritis, and applying cold compresses to relieve joint pain. Patients are advised to avoid self-medication, particularly with antibiotics, steroids, or aspirin, and to seek medical attention if fever persists for more than five days or if they experience symptoms such as severe joint pain, dizziness, decreased urine output, bleeding, or jaundice. 

Hospitalisation is rarely required, except in severe cases or among high-risk groups such as the elderly, pregnant women, and individuals with comorbidities. At the primary healthcare level, all fever cases should be examined by a medical officer, with other illnesses like dengue and malaria ruled out. If chikungunya is suspected, symptomatic treatment with paracetamol and, if necessary, non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen, naproxen, or diclofenac is recommended. However, the use of steroids is discouraged. In pregnant women, only paracetamol or mefenamic acid is considered safe, with NSAIDs to be avoided during the third trimester. 

The NVBDCP stresses that in cases of “hemodynamic instability, altered sensorium, or severe incapacitating arthritis not responding to paracetamol or NSAIDs for more than 15 days,” referral to a higher centre is advised. At secondary or tertiary hospitals, patients are evaluated by physicians who conduct ELISA tests for chikungunya and monitor vital signs closely. The overall management remains supportive and symptomatic, as “paracetamol and NSAIDs are commonly used for symptomatic relief, and acetylsalicylic acid (Aspirin) should be avoided.” The guidelines also highlight that not every clinically suspected case during an epidemic requires serological testing. Preventive measures such as mosquito nets, repellents, and avoiding mosquito bites during the febrile phase are also emphasised to prevent further transmission. 

Health