Workers in protective suits are seen at a checkpoint for registration and body temperature measurement, at an entrance to a residential compound in Wuhan, Hubei province, China February 13, 2020. China Daily via REUTERS

A resident scans a QR code with her mobile phone to pay for protective equipment purchased through group orders at a residential compound in Wuhan, Hubei province, China February 21, 2020. REUTERS/Stringer

A delivery worker standing on his electric bicycle passes food to customers over barriers built to block an entrance of a residential apartment in Wuhan, Hubei province, China February 26, 2020. REUTERS/Stringer

Barbed wire and boards block the entrance of a residential compound in Wuhan, Hubei province, China February 22, 2020. REUTERS/Stringer

Construction workers place barriers on a street in Wuhan, Hubei province, China February 23, 2020. REUTERS/Stringer

A boarded-up entrance to a residential compound is seen in Wuhan, Hubei province, China February 22, 2020. REUTERS/Stringer

Barbed wire is seen at an entrance to a residential compound in Wuhan, China February 22, 2020. REUTERS/Stringer

A resident enters a plastic tent with disinfectant sprayed inside at an entrance of a residential compound in Beijing, China February 21, 2020. REUTERS/Tingshu Wang

Meituan and JD.com delivery workers wearing face masks stand outside a residential compound where delivery workers are not allowed in as part of the measures to prevent and control the spread of coronavirus, in Beijing, China February 8, 2020. REUTERS/Stringer

A boarded-up entrance is seen at a residential compound in Wuhan, Hubei province, China February 22, 2020. REUTERS/Stringer

A man walks on a street towards piles of soil blocking the road to prevent outsiders from entering the community, on the outskirts of Beijing, China January 29, 2020. REUTERS/Carlos Garcia Rawlins

A woman wearing a face mask walks through a device that sprays disinfectant at an entrance to a residential compound, in Tianjin, China February 11, 2020. cnsphoto via REUTERS

Barriers block the entrance to a residential compound in Wuhan, Hubei province, China February 22, 2020. REUTERS/Stringer

Residents wearing face masks buy food at a grocery stall that is set up outside a residential compound in Beijing, China February 21, 2020. The banner reads, "Protection against epidemic, make purchases orderly, wear face masks, keep a distance." REUTERS/Tingshu Wang

Village committee members wearing face masks and vests guard at the entrance to a community in Tianjiaying village, on the outskirts of Beijing, China January 29, 2020. REUTERS/Carlos Garcia Rawlins

A man has his temperature checked at a checkpoint to a hutong neighborhood in Beijing, China, February 25, 2020. REUTERS/Thomas Peter

A worker takes the temperature of a man at the entrance to a residential compound in Wuhan, Hubei province, China February 1, 2020. China Daily via REUTERS

A passage blocked by barricades and shared bicycles is seen in Wuhan, the epicenter of the novel coronavirus outbreak, in Hubei province, China February 20, 2020. REUTERS/Stringer

Metal sheets block a road to prevent outsiders from entering a community on the outskirts of Beijing, China January 29, 2020. REUTERS/Carlos Garcia Rawlins

People wearing face masks walk past a boarded-up entrance of a residential compound in Wuhan, Hubei province, China February 22, 2020. REUTERS/Stringer