Hong Kong health authorities on Thursday revealed a man had tested positive again for the coronavirus nearly three weeks after he was discharged, although the risk of community infection is low.

The man was admitted with a fever to Queen Mary Hospital in Pok Fu Lam on March 24, where he was confirmed to have Covid-19. He was discharged on April 16 after two consecutive negative test results. On Tuesday, he sought treatment at the same hospital’s Accident and Emergency Department for abdominal pain and diarrhoea, where his deep throat saliva sample tested positive for the virus. He is currently in a stable condition in hospital.

Dr Chuang Shuk-kwan (left) and Dr Lau Ka-hin (right). Photo: inmediahk.net.

However, Hospital Authority Chief Manager for Quality and Standards Dr Lau Ka-hin said the risk of infection to the community between the patient’s initial discharge and re-admission was low: “Expertise considers that this is the residual virus left in the patient’s body which is not likely to be [a] reinfection at this moment.”

Dr Chuang Shuk-kwan, head of the communicable disease branch of the Centre for Health Protection (CHP), added: “The latest scientific evidence suggests that some people might have prolonged viral shedding, however, the viable virus was not detected by viral culture after 10 days in spite of persistent positive [polymerase chain reaction] tests,” in reference to the detection of the presence of antigens.

Viral shedding refers to the expulsion and release of viral residue after successful infection and reproduction.

File photo: GovHK.

The Centre for Health Protective also confirmed an additional four imported cases – all men aged 11, 29, 40 and 47 – returning from Pakistan via Doha.

The city has recorded 1,044 cases of Covid-19 and four deaths since January. First detected in China’s Hubei province, the novel virus has infected more than 3.7 million people and led to over 269,500 deaths, according to researchers at Johns Hopkins University.

Following a two-week stint with no cases of local transmission, the government is set to relax certain social distancing measures at midnight on Thursday.

Jennifer Creery

Jennifer Creery is a Hong Kong-born British journalist, interested in minority rights and urban planning. She holds a BA in English at King's College London and has studied Mandarin at National Taiwan University.