Shanghai added a record 13,354 new Covid-19 infections on Tuesday, boosting the national caseload to its highest since the disease’s outbreak, underscoring why authorities in China’s commercial hub are in no hurry to lift a citywide lockdown. Authorities kept the city of 25 million residents locked down, after mass testing found 73,000 infections since March 1. The local government reversed its earlier plan to lift the lockdown on Puxi on Tuesday. The 13,354 infections was the highest one-day increase, topping the previous one-day high of 9,006 on Monday, translating into more than 33 times Shanghai’s total infections before the latest round of outbreak. The vast majority of Shanghai’s infections were asymptomatic, with 268 symptomatic cases on Monday, compared with 425 a day earlier. Still, the authorities were taking no chances with the highly transmissible Omicron variant, vowing to track down, quarantine and deal with every single case to achieve what the government calls a “dynamic zero” Covid-19 policy. “Once confirmed, all new cases will be transferred [to designated quarantine sites],” the Shanghai government’s Deputy Secretary General Gu Honghui said at a media briefing on Tuesday. “All new infections must be settled day by day, and no one should be left unattended.” Shanghai had earlier adopted a phased lockdown on both sides of the Huangpu River that cuts through the city. Pudong, the eastern bank of the river and the heart of the city’s financial infrastructure and manufacturing area, was shut down from March 28 through April 1, while Puxi on the western bank was supposed to be shut from April 1 through 5. Both plans were shelved indefinitely after the surge in cases. Businesses, schools, public parks and entertainment centres have all been shut while nearly every resident has been instructed to remain at home. Walt Disney’s Shanghai Disneyland resort has been shut since late March, while Tesla’s Gigafactory3 in Pudong had halted several days of production . Hundreds of flights have been cancelled at Shanghai’s Pudong and Hongqiao airports, as travellers could not get to the airfields, and even cargo services had been suspended. The Shanghai Stock Exchange, the larger of China’s two equity bourses, kept trading throughout the lockdown, forcing hundreds of technicians and officials to sleep on the premises to keep the world’s second-largest capital market running. The exchange was shut on Monday and Tuesday to observe the tomb-sweeping Ching Ming Festival, a public holiday. “The surging cases have threatened Shanghai’s role as the gateway city” to China, said Wang Feng, chairman of Shanghai-based financial service group Ye Lang Capital. “A citywide lockdown that disrupts production and operations will siphon off foreign businesses’ interest in expanding their footprint in China.” A survey of 163 US companies on April 1 by the American Chamber of Commerce showed that 99 per cent of them had been affected by the latest outbreak in Shanghai. About 60 per cent of them reported slower or reduced production because of a lack of employees, inability to obtain supplies, or government-ordered lockdowns. Any relaxation in Shanghai’s lockdown would take place step-by-step, starting by allowing residents and businesses at low-risk areas to resume normal life and work once the city’s outbreak is under control, according to two government officials familiar with the plan. Nationwide, China reported a total 16,412 cases on Tuesday. In Jilin province in northeastern China, more than 2,850 new infections were reported, taking the total to 56,000 in this round of outbreak. Shanghai authorities began a three-day citywide mass testing for the Covid-19 disease. Several Y-20 military aircraft loaded with 2,000 medical staff from the People’s Liberation Army (PLA) arrived at the Hongqiao airfield in Puxi on Sunday night, carrying testing equipment and protective gear. Shanghai’s much lauded success in keeping the Covid-19 disease at bay lies in tatters, as the caseload since March 1 has far surpassed the sum total of the previous two years. The mass testing exercise is a “crucial showdown” to contain the unprecedented outbreak in Shanghai’s pursuit of the dynamic zero-Covid goal by April 15, two officials said, declining to be named. Shanghai has reserved more than 77,000 quarantine beds for the Covid-19 cases and listed 62 potential venues including stadiums, exhibition halls, and hotels that could be turned into temporary hospitals. But the number of beds may still not be enough to house all the new infections amid the sporadic spread of the disease. Tens of thousands of beds in neighbouring cities such as the Zhejiang provincial capital of Hangzhou have been requisitioned and prepared to accommodate infected residents and their close contacts, according to sources familiar with the matter. As many as 10,000 medical staff have arrived from 10 provinces to help Shanghai conduct its mass testing, in an unrivalled level of support, according to a report by Xinhua News Agency. Licensed vehicles are still allowed on Shanghai’s streets, including fire engines, ambulances and delivery trucks for food and daily essentials, going some ways towards allaying counting worries about emergency services and daily supplies for residents after some couriers and drivers were infected.