Hanoi Chairman Chu Ngoc Anh said Wednesday afternoon that the city has locked down the National Hospital for Tropical Diseases in Dong Anh District to curb the spread of the disease and protect its medical workers.

The decision was taken a day after a male doctor at the hospital tested positive for the coronavirus during an overseas trip. His close contacts are being traced in Dong Anh, Ba Dinh, Dong Da, Tay Ho and Hoang Mai districts. His residence in Ba Dinh’s Ngoc Khanh Ward has been locked down as well.

The lockdown means that the hospital has stopped receiving patients starting Wednesday. All employees of the hospital are being tested. So far, 14 of more than 800 samples have tested positive, though more tests have to be done before the result is confirmed.

Deputy health minister Do Xuan Tuyen said the lockdown is expected to last until May 19.

Tran Thi Nhi Ha, director of the Hanoi health department, said no hospital employee would be allowed to go out, but treatment for admitted Covid-19 patients will continue. Other hospitals will handle future cases, and field hospitals might be deployed for the purpose as well.

The National Hospital for Tropical Diseases has been responsible for handling all Covid-19 cases in the north ever since the nation’s first outbreak early last year. Nearly 1,000 patients have been treated in the hospital since.

Hanoi has recorded four Covid-19 community transmissions since last week. Nationwide, 38 cases have been recorded in seven localities: Ha Nam, Vinh Phuc, Hanoi, Hung Yen, Da Nang, Yen Bai and HCMC.