"Now the spread of the epidemic in Shanghai is very wide, and it may have reached 70 percent of the population, which is 20 to 30 times more than (in April and May)," Chen Erzhen, vice president at Ruijin Hospital and a member of Shanghai's Covid expert advisory panel, told Dajiangdong Studio, owned by the Communist Party mouthpiece People's Daily.
The city was under a gruelling two-month lockdown from April when over 600,000 residents were infected with the virus and many were put in mass quarantine centres.
However after the hardline restrictions were abruptly loosened last month without much preparation, there was a massive jump in the number of cases. And now, the Omicron variant is spreading rampantly across the city.
Chen added that his Shanghai hospital was seeing 1,600 emergency admissions daily -- double the number prior to restrictions being lifted -- with 80 percent of them Covid patients.
"More than 100 ambulances arrive at the hospital every day," he was quoted as saying, adding that around half of emergency admissions were vulnerable people aged over 65.
At Tongren Hospital in downtown Shanghai, AFP reporters saw patients receiving emergency medical attention outside the entrance of the overcrowded emergency ward on Tuesday.
The corridors overflowed with dozens of elderly patients lying on beds crammed together, hooked up to IV drips. Some patients wore oxygen masks attached to bedside canisters.
In Beijing, Tianjin, Chongqing and Guangzhou, and other big cities the wave has already peaked.
In neighbouring Zhejiang province, disease control authorities said Tuesday that there had been one million new infections in recent days and that the province was entering a peak plateau for Covid.
Meanwhile, Chinese officials are readying for a virus wave to hit China's underresourced rural interior, as millions of people prepare to travel back to their hometowns for the week-long Lunar New Year public holiday beginning January 21.
(With inputs from agencies)
