ECDC surveillance data reports 32,529 confirmed chikungunya cases and 9 deaths across the Americas in the current reporting period. Central and South American countries are bearing the heaviest burden, with Brazil, Paraguay, Bolivia, and Argentina among the hardest hit. The surge follows a pattern of expanding arboviral disease activity across the region that has already produced record dengue seasons.
What is chikungunya?
Chikungunya is a mosquito-borne viral disease caused by an alphavirus in the Togaviridae family. It spreads through the bite of infected Aedes aegypti and Aedes albopictus mosquitoes - the same vectors that transmit dengue, Zika, and yellow fever. The name comes from the Kimakonde language of southern Tanzania, where the virus was first described in 1952. It translates roughly to "that which bends up," describing the stooped posture of patients doubled over by severe joint pain.
The hallmark of chikungunya is sudden onset of high fever (often above 39C/102F) accompanied by intense bilateral joint pain, particularly in the hands, wrists, ankles, and feet. The acute phase lasts 7-10 days. Most patients recover, but here is what sets chikungunya apart from other mosquito-borne infections: the joint pain can persist for weeks, months, or even years after the fever resolves.
Studies from the 2005-2006 Reunion Island outbreak found that 60% of patients still reported joint pain 3 years after infection. A 2015 study in Colombia documented persistent arthralgia in 25% of patients at 20 months. This chronic phase can be debilitating, resembling rheumatoid arthritis and significantly reducing quality of life.
How does it differ from dengue?
Chikungunya and dengue share the same mosquito vectors, overlap geographically, and can co-circulate in the same communities. Distinguishing them clinically is difficult during the acute phase, and co-infections with both viruses have been documented.
Key differences: dengue carries a higher mortality risk, particularly in its severe form (dengue hemorrhagic fever/dengue shock syndrome), which can be fatal. Chikungunya is rarely fatal - the case fatality rate is typically below 0.1% - but the chronic joint pain it causes imposes a longer-term burden on survivors. Dengue causes thrombocytopenia (low platelet count) and can cause bleeding, while chikungunya does not.
From a public health perspective, both are driven by the same vector populations and respond to the same mosquito-borne disease prevention strategies. Controlling Aedes mosquitoes reduces transmission of both diseases simultaneously.
Why the surge now?
Several factors are converging to push chikungunya case counts higher across the Americas.
Expanding mosquito range. Aedes albopictus (the Asian tiger mosquito) has established permanent breeding populations across southern Europe, the southern United States, and parts of South America where it was previously absent. Warmer average temperatures allow mosquitoes to breed at higher elevations and survive longer into what used to be cooler seasons. This climate-driven expansion increases the geographic area where chikungunya transmission is possible.
Population susceptibility. Chikungunya first arrived in the Americas in late 2013, reaching the Caribbean before spreading rapidly through Central and South America. By 2015, over 1.7 million suspected cases had been reported across 45 countries and territories. After that initial wave, transmission declined as a large portion of the population had been infected and gained immunity. Ten years later, a new generation of susceptible individuals - children born after 2014-2015 and people who weren't infected in the first wave - provides fresh fuel for the virus.
Urbanization. Aedes aegypti is an urban-adapted mosquito that breeds in small containers of standing water: flower pots, discarded tires, water storage drums, clogged gutters. Rapid urbanization across Latin America, often without adequate waste management or drainage infrastructure, has multiplied mosquito breeding habitat. Over 80% of Latin America's population now lives in urban areas.
Treatment and vaccines
There is no specific antiviral treatment for chikungunya. Management is supportive: rest, fluids, and pain relief with acetaminophen. NSAIDs like ibuprofen should be avoided until dengue is ruled out, because NSAIDs can worsen bleeding in dengue patients and the two diseases are often clinically indistinguishable in the early phase.
The FDA approved Ixchiq (VLA1553), manufactured by Valneva, in November 2023 - the first chikungunya vaccine authorized anywhere in the world. It is a live-attenuated single-dose vaccine that showed 98.9% seroconversion in clinical trials. However, distribution has been limited. The vaccine is approved for adults 18 and older in the US and has received a positive opinion from the European Medicines Agency, but it has not yet been deployed at scale in the Latin American countries where transmission is highest. Cost, cold-chain logistics, and regulatory timelines in individual countries have slowed rollout.
Protecting yourself
Prevention centers on avoiding mosquito bites, especially during daytime hours when Aedes mosquitoes are most active (peak biting occurs in early morning and late afternoon).
Use EPA-registered insect repellents containing DEET (20-30%), picaridin (20%), or oil of lemon eucalyptus. Apply to exposed skin and reapply as directed. Wear long sleeves and long pants when possible. Stay in accommodations with window screens or air conditioning. Sleep under a permethrin-treated bed net if screens are not available.
Eliminate standing water around your living space. A single discarded cup holding rainwater can produce hundreds of Aedes eggs. Travelers to affected areas in Central and South America should be aware that chikungunya is actively circulating alongside dengue and take bite-avoidance measures seriously.
Track the chikungunya situation across the Americas on the PandemicAlarm map and review our dengue global spread page for related context on the Aedes-borne disease surge.