CDC alerts travelers as chikungunya virus spreads in China: Why mosquito viruses are back in the spotlight

The United States Centers for Disease Control and Prevention (CDC) has raised a Level 2 travel notice for Guangdong Province, China, warning travelers to “practice enhanced precautions” amid a growing chikungunya virus outbreak.

The outbreak, mainly centered in Foshan city, has already infected over 7,000 people since mid-2025, prompting urgent global attention. Chikungunya, a mosquito-borne disease spread by Aedes mosquitoes (the same species behind dengue and Zika), causes symptoms ranging from high fever and debilitating joint pain to rash and fatigue. While fatalities are rare, lingering joint discomfort can last for months or years, highlighting why prevention is critical.


What is Chikungunya?

Chikungunya is a viral disease caused by the chikungunya virus, identified in the 1950s in Tanzania. Its name comes from a local phrase meaning “to become contorted,” reflecting the severe joint pain sufferers experience. The virus spreads through the bite of infected Aedes aegypti and Aedes albopictus mosquitoes, which are active during the day and commonly breed in standing water items like flowerpots and containers. The virus is not transmitted person-to-person, except via rare blood exposure or from a mother to her child around the time of birth.


Why is the CDC alerting travelers?

In response to an explosion of cases in southern China, the CDC elevated its travel advisory to Level 2: Practice Enhanced Precautions for Guangdong Province, especially Foshan City. Local authorities are battling the spread with rapid measures such as mosquito-spraying, drone surveillance, elimination of standing water, and fines for stagnant water in homes.



Symptoms to watch for

Chikungunya typically appears 3-7 days after a mosquito bite. Symptoms usually include:

Sudden high fever

Severe joint pain, often symmetrical and debilitating

Headache, muscle pain, joint swelling

Rash, nausea, fatigue, and sometimes eye irritation

Fortunately, fatalities are rare, estimated at 0.1% to 0.001%, but the very young, elderly, and individuals with chronic illnesses face heightened risks. While most patients recover in about a week, joint pain can persist for months or even years, leading to chronic disability.


Who is at higher risk?

Although chikungunya is rarely fatal, certain groups face elevated risk:

Newborns, especially if infected around the time of delivery, may suffer severe outcomes; hence, pregnant women are advised to reconsider traveling to outbreak areas or consult healthcare providers.

Older adults (65+) and individuals with diseases like heart disease, diabetes, or respiratory illnesses are more likely to face complications.

People with underlying health conditions such as diabetes, heart disease, or high blood pressure.

Healthcare professionals stress caution also for travelers who fall into these categories when considering trips to affected areas.


Diagnosis and treatment

There is no specific antiviral treatment for chikungunya. Hence, medical guidance focuses on supportive care, such as:

Rest, plenty of fluids

Acetaminophen (paracetamol) for fever and pain

Avoid NSAIDs like ibuprofen or aspirin until dengue has been ruled out, as those medications may increase bleeding risks

Diagnosis may involve RT-PCR tests, which detect the virus in blood early, or antibody tests when symptoms have persisted for more than a week.


Prevention: Your best defense

Vaccination: Two chikungunya vaccines are approved in the US. So, travellers to outbreak regions are encouraged to get vaccinated. Pregnant travelers should defer until after delivery, but may discuss risks and benefits with healthcare providers if travel is unavoidable.

Avoid mosquito bites: Use insect repellent, wear long sleeves and pants, and stay in air-conditioned or well-screened areas.

Eliminate breeding sites: Remove stagnant water from flowerpots, coffee machines, containers, or, as China has enforced, face fines if not cleaned.

Community efforts: Drones, larvae-eating fish, and other mosquito control tools are being deployed to curb the spread.



But why are mosquito viruses back in the spotlight?

Several factors are fueling renewed concern regarding mosquito-borne viruses. First of all, climate change is expanding mosquito habitats, allowing ticks and mosquitoes like the Aedes species to thrive in new regions. Urbanization and extreme weather, like floods, tend to create more mosquito breeding grounds. Moreover, diseases like dengue, Zika, and chikungunya often overlap in symptoms, complicating diagnosis and response.

Additionally, global travel spreads viruses quickly across borders. China's current outbreak has prompted the CDC warning. Europe has already recorded chikungunya outbreaks in France and Italy, along with rising West Nile cases, underlining a wider trend.


What should travelers do now?

The first course of action – review CDC's Level 2 travel notice and think carefully about travel plans to affected regions. Secondly, pack repellent, protective clothing, and mosquito nets. They’re also advised to get vaccinated if eligible and not pregnant, or consult their doctor if expecting. Furthermore, seek medical attention immediately if you develop fever, joint pain, rash, or other symptoms during or after travel.

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