More than 7,000 cases of a mosquito-borne virus have been reported across China’s Guangdong province since July, prompting measures similar to those taken during the Covid-19 pandemic.
In Foshan city, which has been hit the hardest, chikungunya patients must stay in hospital, where their beds will protected with mosquito nets. They can only be discharged after they test negative or at the end of a week-long stay.
Spread through the bite of an infected mosquito, the virus causes fever and severe joint pain, which sometimes can last for years, but is not usually deadly.
Here is what you need to know about the disease.
What is chikungunya and what are the symptoms?
Although rare in China, chikungunya virus outbreaks are common in South and South East Asia and parts of Africa.
Most people bitten by an infected mosquito will develop symptoms of chikungunya within three to seven days.
Apart from fever and joint pain, other symptoms include rash, headache, muscle pain and swollen joints.
In most cases, patients will feel better within a week. In severe cases however, the joint pain can last for months or even years.
Those at risk for more severe disease include newborn babies, the elderly, and people with underlying medical conditions, such as heart disease or diabetes.
There is no cure, but deaths from chikungunya are rare.
The virus was first identified in Tanzania in 1952. It then spread to other countries in sub-Saharan Africa and South East Asia.
To date, it has been reported in more than 110 countries.
The best way to prevent the virus from spreading is to reduce pools of stagnant water that allow the mosquitoes to breed, according to the World Health Organization.
How widespread are the infections in China?
Aside from Foshan, at least 12 other cities in the southern Guangdong province have reported infections. Nearly 3,000 cases were reported in the last week alone.
On Monday, Hong Kong reported its first case – a 12-year-old boy who developed fever, rash and joint pain after travelling to Foshan in July.
The virus is not contagious, and only spreads when an infected person is bitten by a mosquito that then goes on to bite others.
Officials say all the reported cases have been mild so far, with 95% of the patients discharged within seven days.