More than half of mainland China’s Covid-19 patients did not have a fever when admitted to hospital, a leading researcher said on Saturday, calling on the Hong Kong government to introduce social distancing measures such as flexible lunch hours when civil servants resume work next week, as the city recorded its 95th infection.
Chinese University respiratory medicine expert Professor David Hui Shu-cheong, who co-authored the study, also urged for more tests to be conducted in private and public clinics to enable early detection and isolation of suspected cases after the study findings showed more than 80 per cent of coronavirus inpatients had reduced lymphocyte count in their blood.
Hong Kong has been battling the spread of a novel strain of coronavirus, which causes the disease Covid-19.
The newest case, announced by the Centre for Health Protection late on Saturday, concerned a 46-year-old woman admitted to United Christian Hospital in Kwun Tong. She is the daughter-in-law of a 70-year-old woman infected on Thursday after visiting the Fook Wai Ching She Buddhist worship hall. The infection was the 15th related to the North Point venue.
As a close contact of a confirmed case, the younger woman had been held at a quarantine centre in Mei Foo since Thursday.
“She developed sore throat today and her deep throat saliva specimen was tested positive for Covid-19 virus,” the centre said in a statement on Saturday.
It said the woman was in a stable condition. She had not travelled during the virus’s incubation period, and did not visit the worship hall. Her husband and son, who live with her, were also under quarantine.
The government has raised its response to the highest level of emergency and implemented a host of measures to contain the outbreak. The measures included asking most of its staff to work from home since January 29 and closing schools for almost two months. But officials announced earlier this week that civil servants would return to offices from next Monday.
The study, the largest of its kind, was co-authored by Hui, China’s director of the State Key Laboratory of Respiratory Disease Zhong Nanshan, and other mainland specialists. It analysed data of 1,099 Covid-19 patients from 552 hospitals in 30 provinces, autonomous regions, and municipalities in China.
Published in the New England Journal of Medicine, the findings of the study showed the mortality rate was 1.4 per cent among the group of patients with a median age of 47, some 58.1 per cent of them being male. Incubation period of the disease generally ranged between two and seven days, while only 1.9 per cent of the patients had a history of direct contact with wildlife.
Hui, who sits on a Covid-19 government advisory panel reporting directly to the city leader, said even though the patients’ mortality rate was lower than the two to three per cent mortality rate of patients with flu infections, the figure was still significant. “The virus is highly contagious, so a 1.4 per cent mortality rate still means a substantial number of deaths.”
The research team found more than half, or 56.2 per cent of patients had no fever at the time of hospital admission, while the figure dropped to 11.3 per cent after hospitalisation. No abnormalities were found in the radiographic or CT lung scans of 17.9 per cent of patients with a non-severe illness and 2.9 per cent of those with a severe exacerbation.
“The findings show it’s very easy to miss some infections in the community and we can’t just use fever as a marker [for Covid-19],” Hui said. “Some patients may even have lung scans that look fine on admission and are discharged back into the community, causing the virus to spread.”
He said flexible work arrangements and social distancing should be maintained to contain the spread of the disease. “It worries me that some 170,000 civil servants are going back to their offices next week, travelling on public transport. The public and private sector should let their workers continue to work from home, and wherever impossible, at least let them have flexible lunch hours so they don’t all rush to packed restaurants at the same time.”
Hui said the containment measures adopted in the city had been successful in slowing the rise of local infections, limiting new cases to three to four a day, even as infections climbed sharply in places such as South Korea, Italy, and Iran. “But it is not the time to let down our guard.”
Other clinical characteristics of the pathogen discovered in the study include lymphocytopenia, the condition of having an abnormally low level of lymphocytes in the blood, which was found in 83.2 per cent of the patients on admission.
“This is because a viral pneumonia will destroy lymphocytes and white blood cells, while a bacterial pneumonia won’t,” Hui said.
“And since Hong Kong is most affected by the Covid-19 epidemic right now and not other virus infections such as seasonal influenza, a blood test to check the lymphocyte count in a patient can be an effective way of detection.”
The city can carry out only 700 to 800 genome tests a day to confirm Covid-19 infections, which takes two to three hours to produce results. Hui believed blood tests should be carried out more often by clinics for patients with minor symptoms, to allow for earlier detection and isolation.
At a press conference on Saturday, Dr Sara Ho, the Hospital Authority’s chief manager for patient safety and risk management, did not commit to conducting more blood tests, but said public hospitals were gathering and looking at all kinds of patient data, including lymphocyte count.
“We are still at the stage of understanding the disease … but we will make public our findings when they are ready.”