"We followed the news on TV like many others. Because of the Spring Festival holiday, many medical supply factories took the week off, so it was hard to buy such products. We contacted the factories directly so that we could get enough as fast as possible," she said.

"Our fans work in different fields. We let those who work in banks do the accounting, while those working for delivery companies help monitor the transportation of the supplies. We are united because of the outbreak."

The immediate response by the fan groups to the outbreak has been applauded by netizens. Some praised their efficiency and dedication to helping people in need; others said their action had made them "heroes" and had broken the stereotype of fan behavior making the wrong type of headlines.

One netizen commented on Sina Weibo: "Fans are inspired by their idols to highlight crucial domestic social issues. The fans' kindness increases awareness of such endeavors and stimulates more donations."

Fan group culture, known as fan quan, was imported from South Korea, with that country's pop stars and supporters playing a huge role in taking K-pop to a broader audience. Fans gather in groups to meet and share information about their idols. Their activities have played a key role in driving the entertainment industry, but they have also triggered controversy, with some obsessive fans, known as sasaeng, at times breaking the law to support their heroes.

Jerry Lin said: "Fans should do what good fans do. We are also members of society who want to help and contribute."

The first group to launch donations for Wuhan was actor Zhu Yilong's charity fan club on Jan 21, according to Wang Fangyuan from Power China, a nonprofit organization, which harnessed more than 300 Chinese fan groups and helped monitor, transport and distribute donated medical supplies. Soon, more fan clubs joined the effort.

On Jan 28, Zhu, a Wuhan native, donated 1 million yuan to Wuhan's hospitals as well as highlighting the outbreak in the city on his Sina Weibo platform, which has more than 23 million followers.