Health authorities in several cities with new local Covid-19 infections urged residents to stay vigilant and reiterated the use of personal hygiene and protection measures, including wearing masks, maintaining social distancing and paying attention to food safety. In recent days, three new confirmed cases have been reported – in Tianjin, Shanghai and Fuyang, Anhui province. In Tianjin, large-scale nucleic acid testing was conducted on 77,000 residents of the Hangu subdistrict and two blocks neighboring a cold-chain logistics area at the central fishing port in the city’s Binhai New Area.

The areas were classified as medium-risk for Covid-19 after a 38-year-old man, who works at a loading dock of a cold storage company, tested positive, becoming a confirmed Covid-19 patient. Officials urged residents in medium-risk areas not to leave their communities. The coronavirus found to have infected the Tianjin patient was very similar to the strain that spread in North America between March and June, local government officials said. The man tested positive after he handled a shipment of frozen pork. Samples of the outer packaging of the pork, which arrived in Tianjin on October 19 from Germany, tested positive for coronavirus. Tianjin also reported an asymptomatic case – a 48-year-old man who is a stevedore at Tianjin Dongjiang Free Trade Port Zone in the Binhai New Area. A second man, 47, a driver who went to the facilities where the confirmed patient worked and who loaded frozen food, was reported as an asymptomatic case. In Yunnan province, the Gengma autonomous county reported two new asymptomatic Covid-19 infections in individuals from Myanmar. Residents in three communities were required to complete 14 days of home quarantine and schools were suspended.

Shanghai’s government said that all 8,717 people in the city with ties to a confirmed local Covid-19 patient – a 51-year-old man who works as a cargo handler at Shanghai Pudong International Airport – had tested negative for the virus. Twenty-six people who had close contact with the confirmed patient and 186 people who interacted with those individuals have also been quarantined at designated hotels, according to the authorities. A confirmed Covid-19 case, a close contact of the Shanghai patient, was reported in Fuyang, Anhui province. The 50-year-old man also worked as a stevedore at Shanghai Pudong International Airport, the China Daily reports. An increasing number of Shanghai residents are taking tests for coronavirus at designated hospitals before traveling to other cities where negative results may be required.

It is estimated that there have been at least 30 coronavirus cases detected in China in imported food cold chains since the first case in July. Up to now, more than 873,500 samples had been tested by Customs across China, among which 13 had positive nucleic acid test results, media reported. China also has reported more than 3,600 imported cases, and the number has increased rapidly since October. The current daily average of imported cases is 16.6, up 45% since September. China has stopped issuing visas to some foreign nationals while restricting non urgent outbound travel by Chinese citizens, Yin Chengji, Deputy Director of the National Immigration Administration (NIA), told reporters.

China remains vigilant, as more cases may emerge in winter. There might be sporadic cases in some areas in China and some pocket cluster cases in others, Li Bin, Vice Chairman of the National Health Commission, said. “China’s epidemic prevention and control work cannot be relaxed for a single moment,” he added. The country has also done random checks on more than 870,000 samples of imported frozen food, said Bi Kexin, an official at the General Administration of Customs. It is demanding certification from suppliers, and market regulators are taking tougher measures against untraceable frozen food, said Chen Xu, an official at the State Administration for Market Regulation. Chinese respiratory disease expert Zhong Nanshan called for sustained international collaboration in the battle against the Covid-19 pandemic and greater attention to asymptomatic cases, citing relatively strong infectivity.

Brazil resumed the trials of a Chinese Covid-19 vaccine after halting them briefly following the death of a participant in the trial, which was later classified as a possible suicide and thus not related to the vaccine test. The vaccine candidate tested in Brazil is developed by the Chinese firm Sinovac Biotech (Sinovac). A scheduled shipment of Sinovac’s vaccine to Brazil of about 150,000 to 160,000 doses at the end of the month is still being processed. Joao Doria, the Governor of Sao Paulo state where the vaccine is being tested, called the suspension of the study the result of a “domestic political war” with President Jair Bolsonaro, who had previously declared that Brazil would not buy Chinese vaccines.