Staff members work in an inflatable COVID-19 testing lab in Beijing, capital of China. File photo: Xinhua

Beijing reported zero new infections on Wednesday, but health officials warned that it does not indicate zero risk given recent family clustered outbreaks, infections surrounding the capital city that involved a person who works in Beijing but lives in Hebei, and continued mounting pressure from imported cases.

There has been a rising trend in long incubation and mild and asymptomatic cases, and the new variant has been found to be more infectious, all of which has increased pressure on China in its epidemic control efforts, a municipal official said at a press conference on Wednesday.

The official outlined the epidemiological investigation results of a case discovered in late December, revealing that the patient was likely infected after touching the contaminated outer package of steamed buns. 

The first case on the infection chain was a person returning from Hong Kong, who showed symptoms and was confirmed to be infected after completing quarantine on December 12. 

The person, after leaving the quarantine center, stayed in a hotel in Chaoyang district and infected two employees, cases 2 and 3, at a steamed bun shop in the same building. 

Case 4 did not show direct contact with them, but his father had been to the shop and bought some steamed buns. The patient had touched the packages. 

Virus analysis of cases 1 to 3 found they are on the same chain, and the virus strain belongs to the L type Europe family, with no connection to other outbreaks or the new variant first detected in the UK and South Africa. 

Viral loads found in the case 4 patient were too low for full gene sequence analysis, but he was most likely infected by the contaminated packages, taking into consideration the exposure history.

The infection has caused the building where the hotel is located to suspend business, be disinfected and labeled as medium-risk area from December 19. The area was delisted on Wednesday. 

Global Times