The city reported 994 locally transmitted COVID-19 cases, 22,348 local asymptomatic infections, four imported patients and one imported asymptomatic infection on Monday, said the Shanghai Health Commission on Tuesday morning.Of all the local infections, 273 confirmed patients were previously asymptomatic infections. Another 439 confirmed patients and 21,844 asymptomatic cases were detected during central quarantine, while the rest were found in the screening of high-risk people.994 local casesThe first 439 patients tested positive during central quarantine.