Health officials in the United States are advising travelers to stay alert as a mosquito-borne virus continues spreading across various regions, including parts of Asia, Africa, Europe, Latin America, and the Indian Ocean.
Since the start of 2025, the chikungunya virus has led to about 240,000 infections and 90 fatalities across 16 nations, as reported by the European Centre for Disease Prevention and Control (ECDC).
In China, roughly 7,000 cases have been reported since late June, particularly in Foshan, a city in Guangdong province, which is near Hong Kong. This outbreak marks the largest chikungunya incident in China since the virus was first detected there in 2008.
So, what exactly do we know about this virus and its spread?
What is the chikungunya virus?
The chikungunya virus is transmitted through bites from infected Aedes aegypti mosquitoes, which also spread dengue, yellow fever, and Zika virus.
The term chikungunya comes from a word in the Kimakonde language, spoken in parts of Tanzania and Mozambique, meaning “to become contorted.”
Most people experience relief from symptoms within a week, but joint pain can persist for months or even longer in some cases.
While there isn’t a cure for the virus, fatalities are rare. The transmission occurs when an infected mosquito bites a healthy person, injecting the virus into their bloodstream.
Those who are most vulnerable to severe complications include newborns, older adults, and individuals with pre-existing health conditions like heart disease or diabetes.
No specific cure exists for chikungunya, but the death rate remains low, primarily affecting high-risk groups.
When a healthy human is bitten by an infected mosquito, the virus enters their bloodstream. Alternatively, if a non-infected mosquito bites an already infected person, it can then transmit the virus to others.
How serious is the current spread?
The World Health Organization (WHO) indicates that the recent increase in cases began in early 2025, particularly in Indian Ocean Islands such as La Reunion, Mayotte, and Mauritius.
For instance, La Reunion has recorded over 47,500 chikungunya cases and 12 related deaths as of May 2025, reflecting sustained high transmission across the island. The ECDC confirmed that more than 54,000 cases had been reported in La Reunion by mid-July.
This outbreak is now considered the most severe since the 2005-2006 epidemic that resulted in approximately 244,000 to over 300,000 cases, prompting extensive public health measures to control mosquito populations and transmission.
The virus has also spread to nations like Madagascar, Somalia, and Kenya and has shown signs of epidemic-level transmission in Southeast Asia, including a notable increase in cases in Mumbai, India, since July.
The WHO expressed concern over the spike in imported chikungunya cases in Europe, with around 800 cases reported in mainland France since May 1.
In the Americas, Brazil, Bolivia, Argentina, and Peru have reported significant case counts, while infections in China have been identified in at least 12 cities in southern Guangdong province.
Chinese officials indicated that local transmission began from an “imported case” in July, although they didn’t specify the source. Experts attribute this outbreak partly to rising global temperatures creating favorable conditions for mosquito proliferation.
Recently, Hong Kong confirmed its first chikungunya case in six years involving a 12-year-old boy showing symptoms after visiting Foshan.
What actions are taken by China and others to combat the virus?
China has pledged rapid action to control the chikungunya virus’s spread. This includes drone surveillance to locate mosquito breeding sites, and scientists are releasing larger “elephant mosquitoes” whose larvae prey on smaller mosquitoes responsible for disease transmission.
According to reports, residents in impacted areas of China are mandated to eliminate standing water around their homes, including in flowerpots and discarded containers. Failure to comply can lead to fines up to 10,000 yuan—or around $1,400—and potentially criminal charges for obstructing infectious disease prevention.
Additionally, there are reports of infected individuals in Foshan being relocated to quarantine facilities, often with insufficient notice regarding their medical expenses.
Elsewhere, areas like La Reunion and Mayotte have implemented heightened surveillance, mosquito control measures, and targeted vaccination initiatives. In Spain, the Basque Country activated preventive protocols in response to a case discovered just across the border in France, increasing monitoring and encouraging locals to report mosquito sightings through specialized apps.
How can chikungunya be prevented and treated?
Health authorities recommend various strategies to protect against mosquito bites, which are the primary means of preventing the spread of chikungunya.
This includes wearing long clothing, using mosquito repellents, eliminating standing water where mosquitoes breed, and staying indoors in air-conditioned environments or behind mosquito nets if outside.
While there are no specific treatments for the virus, resting and staying hydrated may help ease symptoms. The US Centers for Disease Control and Prevention (CDC) mention that some pain relievers could be unsafe during a suspected infection, advising against non-steroidal anti-inflammatory drugs (NSAIDs) until dengue is ruled out because they could increase bleeding risks.
