(Yicai Global) Nov. 10 -- Shanghai has tested more than 8,700 people who could have been infected with the coronavirus after the city detected its first domestically transmitted Covid-19 case in almost six months. None tested positive, the local health commission said.

A transport worker at Shanghai Pudong International Airport tested positive on Nov. 9 after visiting a hospital the previous day, the commission announced yesterday. The patient was sent to the Shanghai Public Health Clinical Center for treatment and the airport is operating as normal. 

Shanghai is presently hosting the third China International Import Expo with thousands of foreign companies and representatives participating in one of the world's largest face-to-face events this year. 

Based on current understanding, neither the patient’s work nor his course of action before being diagnosed was related to the CIIE, said Wu Jinglei, director of the Shanghai Health Commission. Moreover, the man had not been in contact with frozen foods, which have been suspected of transmitting the virus.

Some 186 people had been in close contact with the man before he tested positive. Health authorities collected more than 520 samples from places where the patient had been before the diagnosis and those proved safe. 

The man lives in Zhuqiao town in Shanghai’s Pudong district and that area is now considered medium-risk, whereas other districts in the city remain low-risk. Residents of Zhuqiao need to present a negative test result for the coronavirus to be able to leave the area. 

As of Nov. 8, more than 1.2 million CIIE visitors had been tested for Covid-19 before entering the National Exhibition and Convention Center in Shanghai and none of the them came back positive. Moreover, the authorities have collected more than 760 samples from the venue with a total area of 24,000 square meters to assure safety. 

Editor: Emmi Laine