The city’s Department of Health reached the decision as relaxed social distancing measures and restored economic activities spark concern over renewed community transmission.
Starting Friday, those visiting or being treated at hospitals and medical facilities that show signs of being infected with flu or severe acute respiratory disease will be tested for Covid-19.
Foreign patients, or Vietnamese returning from abroad for further treatment, will be forced to take a Covid-19 test and closely monitored in the quarantine area of hospitals in accordance with regulations.
Vietnam has not granted entry for people from overseas yet, but those coming with diplomatic, official passports or for special economic projects can enter and will be quarantined for 14 days.
The southern metropolis, home to 13 million people, has recorded 58 infections, with 53 already discharged.
Vietnam has gone 36 straight days without community transmission of the novel coronavirus since April 16. The country's count of active Covid-19 cases is currently 58, while 266 other patients already recovered following treatment.
However, the National Steering Committee for Covid-19 Prevention and Fighting expressed concern at a Thursday meeting over the populace behaving as though the pandemic crisis had passed.
Officials have asked people to keep taking safety measures and not to let down their guard.
The Covid-19 pandemic has thus far affected 213 countries and territories, and reported deaths have crossed 335,000.