Cleaners spray disinfectant fluid to clean the street at Sha Tin, Hong Kong on Saturday. A spike in cases indicates the city has been hit by a third wave of COVID-19. On Sunday, Hong Kong reported 38 newly confirmed cases. Photo: cnsphoto

 A confirmed COVID-19 patient in Hong Kong was revealed on Monday to have donated blood before being confirmed infected, and the news sparked fear of coronavirus infections through blood transfusions, as the city reels from a rebounding epidemic and is stepping up efforts to curb the spread of the new outbreak 

The patient was confirmed infected on Sunday. He donated blood on July 5 at the West Kowloon blood donation station, Hong Kong media hk.on.cc reported Monday, citing the Hong Kong Red Cross Blood Transfusion Service. 

The city reported 52 new COVID-19 cases on Monday with 41 locally transmitted and 11 imported cases. 

Hong Kong Hospital Authority Chief Manager Lau Ka-hin said that they are tracking the whereabouts of the donor's blood. They only know that his blood platelet was used on a patient at the Queen Elizabeth Hospital, and the receptor has not shown any symptom and would be quarantined, the report said. 

About 85 residents donated blood at the same station on the same day of the infected donor, and four working staff at the station made contact with him, according to the report. The donor started to show symptoms on July 9. He was not in the infectious period when he donated blood, Hong Kong health officials said.  

The Hong Kong Red Cross blood transfusion service center has advised all people who have left Hong Kong not to donate blood 28 days after they return to Hong Kong since March 16. The same is true for people who have had close contact with confirmed COVID-19 patients. 

The possibility of COVID-19 infections through blood transfusions is low, as COVID-19 causes short-period viremia, Jin Dongyan, a professor at the School of Biomedical Sciences at the University of Hong Kong, told the Global Times on Monday. 

Viremia is a condition where the virus enters the bloodstream. A Xinhua News Agency report in February said that six of the first 11 COVID-19 convalescent plasma therapy patients in Wuhan had viremia.  But two to three days following the therapy, the viremia disappeared and the patients' condition improved. 

There is little evidence of COVID-19 causing viremia, but the possibility of infections through blood transfusions cannot be ruled out, an anonymous immunologist in Beijing told the Global Times on Monday. 

Hong Kong saw a spike of new COVID-19 cases over the past few days, as the third wave of the pandemic was believed to have started last week in the city. Given the grave situation, the city government has also stepped up anti-epidemic measures to curb the new outbreak.  

Restaurants in Hong Kong are banned from offering eat-in meals from 6pm to 5am and can offer take-out only. 12 types of listed premises, such as gyms and KTVs, will be closed for 7 days to control the COVID-19, Chief Executive Carrie Lam announced on Monday evening.

The ban on mass gatherings is tightened to four people and will come into effect at midnight on Wednesday, Lam said. 

Inbound travelers to Hong Kong who have stayed in COVID-19 high-risk areas in the past 14 days must produce a negative COVID-19 test before boarding, or the airline will be fined, she said. 

Jin believes the circulating strain of coronavirus in Hong Kong may be from Europe or the US, and entered Hong Kong due to lapses in border procedures.