A swift response to the COVID-19 outbreak played an important role in the containment of the epidemic in China, while international cooperation is needed to bring it under control globally, a top Chinese epidemiologist said.

"China responded very fast. It took only a week from issuing the first epidemiological alert to identifying the pathogen for the outbreak, and it only took another four days to develop the first test kits for the coronavirus," Wu Zunyou said. "It created a world record in terms of response to a new infectious disease."

The first alert on the outbreak was issued at the end of December by authorities in Wuhan, Hubei province, and on Jan 7, China CDC successfully isolated the novel coronavirus, Wu said. Days later, China shared the genetic sequence of the virus with the world. By Jan 20, COVID-19 was listed as a notifiable infectious disease under the most strict management in China, similar to plague and severe acute respiratory syndrome.

"Improved scientific and technological development in China in recent years has greatly contributed to the quick response to the disease, making quick identification of the new virus and development of testing kits for diagnosis," Wu said. "We have seen big progress in this aspect compared with the SARS outbreak in China 17 years ago."

Following the COVID-19 outbreak, China quickly adopted a number of measures for epidemic control and prevention, including universal use of masks and social distancing measures, strict isolation of cases and contact tracing of close contacts of confirmed cases, which in combination had effectively contained the virus, he added.

Considering the severity of novel coronavirus pneumonia, such stringent measures were necessary for epidemic control, Wu said. For example, patients with the virus can be infectious one or two days before they show symptoms, while SARS patients could only infect others at least five days after they started to display symptoms, which made it important for seemingly healthy people to wear masks to prevent transmission of the virus, he said.

With the major epidemic brought under control in China, the country now faces tremendous pressure from imported cases, which have constituted the majority of cases reported recently, Wu said. "Controlling the COVID-19 outbreak is not for one country," he said. "It is a global endeavor."