A mosquito-borne virus that leaves victims in crippling pain and has triggered Covid-era restrictions in China is already in the US, experts say.

Chikungunya virus can lead to sudden, excruciating joint pain in the hands and feet, sometimes so intense that it leaves sufferers unable to move normally for months.

Southern China is currently confronting its largest outbreak since at least 2008, with over 7,000 cases reported in Foshan, at the center of the outbreak, and infections spreading to 12 other major cities. Heavy rains and warm weather have caused a surge in mosquito populations, driving the outbreak.

Dr. Louisa Messenger, a mosquito researcher in Nevada, told the Daily Mail: ‘This outbreak in China is very concerning. It could already be here in the US — and really it’s just one plane flight away.’

Officials have already detected 46 cases of chikungunya in the US this year, all linked to travelers returning to the country from abroad.

The number of cases linked to China’s outbreak is unclear, but the CDC has issued a warning for travelers to the country regarding the virus, as well as for nine other countries, including Bolivia and Sri Lanka.

Estimates indicate that 1.6 million people travel between the US and China annually. Experts warn that it only takes a single mosquito bite on one infected traveler to spread the virus throughout America.

The US has previously experienced limited local transmission of the disease, most recently in 2014 and 2015, after cases were detected in Florida and Texas.

The epicenter is Foshan, on China’s southern coast, where heavy rains and warm temperatures have led to an explosion in the mosquito population (Image above is Foshan) 

Chikungunya is carried by the Aedes mosquito, which has black and white striped legs and remains common across much of the US.

Officials say infections are usually detected quickly and public health teams respond fast to prevent wider spread.

This normally involves the widespread release of pesticides to kill mosquitoes and prevent the disease from spreading.

Here’s everything you need to know about the virus:

How do I tell if I have chikungunya? 

Chikungunya is a disease caused by a virus spread by mosquitoes.

It can only be caught from mosquito bites, with infected people developing symptoms in two to seven days.

People infected with the virus suffer from a sudden high fever, normally around 103 Fahreheit (39 Celsius), which happens within two to seven days of infection.

They may also suffer from a rash, headache, nausea, fatigue and joint pain.

In serious cases, patients may suffer from pain in the hands and feet that is so bad it leaves them struggling to carry out normal activities. 

The above map shows the area in China where US travelers are being advised to take enhanced precautions because of the outbreak

Dr Augustine Anadu, an obstetrician who previously treated a 24-year-old with the disease, told the Daily Mail about the symptoms of a patient he treated.

The individual was admitted with extreme fatigue, a fever around 102 Fahrenheit (39 Celsius) and joint pain that ‘hurt so bad he could barely work’, the doctor said.

It was only when the patient revealed he had returned from Ethiopia, where the disease is present, that tests for chikungunya were ordered, which revealed the infection.

The patient recovered within three days after receiving IV fluids and painkillers.

Is chikungunya deadly?

Chikungunya is rarely fatal, and kills less than one in 1,000 patients.

But it can leave people with lifelong complications, including inflammation and joint pain that lasts for months to years.

Doctors also say patients with long-lasting complications can have symptoms similar to rheumatoid arthritis, an autoimmune condition that causes pain, swelling and stiffness in joints.

Doctors warn that infants, the elderly and those with underlying conditions are particularly at risk because they have weaker immune systems.

A worker is pictured spraying insecticide onto plants in Guangzhou, Guangdong province, China, amid an outbreak of chikungunya virus

A hospital worker also pictured spraying plants outside a hospital in Foshan, China, at the epicenter of the outbreak

Could the disease spread in the US?

Infectious diseases have previously been introduced into the US mosquito population from abroad, including in recent years.

In 2022 and 2023, 71 cases of locally transmitted dengue fever, a potentially fatal mosquito-borne disease, were reported in Florida and Texas, in at least a decade.

In 2023, nine cases of locally transmitted malaria were also reported in the US, with seven in Florida and one each in Texas and Arkansas.

In both cases, experts said it was likely that travelers infected with the diseases had arrived in the US and then been bitten by local mosquitoes, which then spread the diseases to someone else when they bit another person.  

Dr Messenger added: ‘Mosquito-borne diseases are really important because they are much more difficult to control than Covid, the flu or RSV because they involve mosquitoes, which can breed in as little water as fits in a bottle cap.

‘People should be concerned about these diseases, wear topical repellents, wear long sleeves, and get vaccinated against them if they can.’

Chikungunya virus cannot be spread from person to person, and is instead only spread by the bites of mosquitoes.

Will it trigger restrictions like in China?

In China, to contain the outbreak, authorities are spraying disinfectant in Foshan and other cities affected by the outbreak.

Officials are also imposing 10,000 yuan ($1,400 fines) and cutting off electricity to people who do not empty bottles, flower pots or other outdoor objects containing standing water.

Reports suggest patients are being quarantined in the hospital for at least a week, and authorities briefly also enforced a strict two-week home quarantine before learning the virus couldn’t be passed from person to person.

Shown above is an individual outside Beijing, China, hanging up a mosquito trap, used to measure the mosquito population in an area 

Experts said it was unlikely that the US would impose similar extreme restrictions if there was an outbreak of the virus.

Instead, they suggest that there would likely be a mass insecticide spraying campaign to eliminate the infected mosquitoes.

How is the disease treated?

There is no specific treatment for infections with the virus.

Doctors instead focus on trying to ease symptoms through rest, fluids and over-the-counter pain relief medications like acetaminophen (Tylenol).

Vaccinations are recommended for those visiting areas with an outbreak or that may pose a higher risk of infection.

The CDC has approved two vaccines against the disease in the US, the first of which was approved in 2023. 

What is the CDC saying? 

The CDC is warning Americans to take extra precautions while traveling to Guangdong province and surrounding areas affected by the outbreak.

It has put a level two alert in place, advising travelers to wear insect repellent, long-sleeved shirts and pants, and to stay in places with air conditioning.

Travelers are also advised to get vaccinated against chikungunya, with two vaccines available that have been approved in the US.

It also says that pregnant women should avoid traveling to the area because they are at higher risk from contracting the virus.

Warnings over chikungunya are also in place for nine countries and territories: Bolivia, China, Kenya, Madagascar, Mauritius, Mayotte, Reunion, Somalia and Sri Lanka.