There is growing alarm in China that official efforts to control the spread of Chikungunya virus, a non-fatal mosquito-borne disease that has been spreading in the south of the country, are infringing on people’s personal rights.

A single mother living in Zhanjiang, a port city in Guangdong province, posted a video on social media this week showing a group of people, including a uniformed police officer, entering her children’s bedroom in the middle of the night and taking blood samples from the boy and the girl, without their mother’s presence or consent. The mother had been working a night shift so was not at home.

According to Chinese media, a local pharmacy had reported the family to the health authorities after the son had presented with a fever.

A hashtag related to the incident has been viewed nearly 90m times on Weibo, with many users expressing alarm about the behaviour of the authorities.

Health authorities in Guangdong are on high alert because of an outbreak of Chikungunya that started about a month ago in Foshan, a city 260km from Zhanjiang. There have been about 8,000 reported cases so far, and at least one imported case in Hong Kong, a city that borders Guangdong.

Chikungunya is a mosquito-borne disease that can only be spread by being bitten by an insect with the virus. Symptoms include fever, muscle and joint pain, nausea and a rash. In rare cases, symptoms can last for months or even years. But it is rarely fatal. Babies, elderly people and people with underlying health conditions are most at risk.

There are regular Chikungunya outbreaks in Asia, Africa and the Americas, but this is the first time that there has been a major occurrence in China.

China’s Covid-19 prevention measures were among the strictest in the world, and there is a well-oiled machine to control the spread of disease that can be activated at short notice.

On 2 August, Wang Weizhong, Guangdong’s governor, said that China would “strive to win the battle against the Chikungunya fever epidemic” and ordered a range of measures.

These include eradicating mosquito breeding grounds such as pools of stagnant water, mobilising the public to empty out pots and pans that might be collecting water, encouraging the use of mosquito coils and nets and using mosquito repellent.

But the authorities have also been resurrecting surveillance and reporting measures which hark back to the zero-Covid era, in which people’s daily lives were strictly monitored and controlled.

On 4 August, the Foshan local authorities announced that all pharmacies would have to report the sale of certain drugs used for treating fevers.

This appears to be how the children in Zhanjiang were identified. Chinese media quoted a local official who said that attempts had been made to contact the mother. After the outcry, the local health authorities said they were investigating the case.

Additional research by Lillian Yang