Big data facilitates search for source of fare-up

The fight against infectious diseases is relentless and Wang Quanyi has focused on this fight for 18 years.

Now working as the director of the epidemic and endemic disease control office under the Beijing Center for Disease Prevention and Control, Wang discovered big data is playing an important role in preventing and controlling the COVID-19 pandemic.

Beijing had reported no new locally transmitted COVID-19 cases for 57 days. But on June 11, Wang and his team received a new case from Xicheng district at 2 am.

The infected man, 52, surnamed Tang, reported every place he had visited since May 30 to Wang's team. From that they set about to locate the source of infection as soon as possible.

Tang's activities could be verified through big data analysis because he used his smartphone to pay vendors and chat.

Wang's colleague Dou Xiangfeng said: "Tang's payment records clearly show the stores he went to, which saved a lot of time for on-site research."

Tang's description of his visit to the Xinfadi wholesale market in southwestern Beijing's Fengtai district on June 3 proved to be critical for authorities. It helped determine that the market was the source of most of the new local infections.

Dou also shared the information with other related departments, which launched big data screening to ensure accuracy.

Wang said he was not surprised by the speed the Xinfadi cases were traced because his team is constantly alert to COVID-19 infections.

When he first heard of COVID-19 at the end of 2019, Wang and his team started to collect data and determine the methods of laboratory testing and monitoring plans. They stay vigilant. He told the young people in his team: "You should learn about the history of the pandemic, the latest developments at home and abroad, local risks and how to deal with the situation. Then you can be called a professional."

The senior professional started his career at the Beijing Center for Disease Prevention and Control in 2002. When the capital was hit by SARS in 2003, the center could only confirm cases based on epidemiological history and clinical manifestations. This was because the center had no capabilities of laboratory testing.

After this, Wang and his colleagues made efforts to build a better prevention and control network.

During the H1N1 pandemic in 2009, Beijing established a complete laboratory testing system. It set up 55 pandemic test laboratories and popularized nucleic acid test techniques in major hospitals. This helped Wang and his colleagues respond quickly when H7N9 bird flu was discovered in 2013 and when China's first imported yellow fever case was detected in 2016.

In recent years, Wang's team has achieved many internationally influential results in the areas of influenza disease burden, early warning monitoring and vaccine effectiveness evaluation.