Beijing: People who are older or have underlying diseases like high blood pressure and diabetes may be at a higher risk of death from the new coronavirus (COVID-19), according to a study published in The Lancet journal.
The observational study was carried on 191 patients with confirmed COVID-19 from two hospitals in Wuhan, China.
The study is the first time researchers have examined risk factors associated with severe disease and death in hospitalised adults who have either died or been discharged from hospital.
"Older age, showing signs of sepsis on admission, underlying diseases like high blood pressure and diabetes, and the prolonged use of non-invasive ventilation were important factors in the deaths of these patients," said Zhibo Liu from Jinyintan Hospital, China.
"Poorer outcomes in older people may be due, in part, to the age-related weakening of the immune system and increased inflammation that could promote viral replication and more prolonged responses to inflammation, causing lasting damage to the heart, brain, and other organs," Liu said.
In the study of 191 patients, 137 were discharged and 54 died in hospital.
However, the researchers note that interpretation of their findings might be limited by the study's sample size.
They present new data on viral shedding, which indicates that the median duration of viral shedding was 20 days in survivors (ranging from 8 to 37 days), and the virus was detectable until death in the 54 non-survivors.
While prolonged viral shedding suggests that patients may still be capable of spreading COVID-19, the researchers caution that the duration of viral shedding is influenced by disease severity.
They note that all patients in the study were hospitalised, two-thirds of whom had severe or critical illness.
"The extended viral shedding noted in our study has important implications for guiding decisions around isolation precautions and antiviral treatment in patients with confirmed COVID-19 infection," said Professor Bin Cao from the China-Japan Friendship Hospital and Capital Medical University, China.
"However, we need to be clear that viral shedding time should not be confused with other self-isolation guidance for people who may have been exposed to COVID-19 but do not have symptoms, as this guidance is based on the incubation time of the virus," said Cao.
The researchers recommend that negative tests for COVID-19 should be required before patients are discharged from hospital.
In severe influenza, delayed viral treatment extends how long the virus is shed, and together these factors put infected patients at risk of dying, they said.
The researchers noted that effective antiviral treatment may improve outcomes in COVID-19, although they did not observe shortening of viral shedding duration after antiviral treatment in the study.
For the first time, the study describes the complete picture of the progression of the COVID-19.
The median duration of fever was about 12 days in survivors, which was similar in non-survivors.
However, the cough may last for a long time — 45 per cent of survivors still had cough on discharge, the study found.
In survivors, dyspnoea (shortness of breath) would cease after about 13 days, but would last until death in non-survivors.
The study also illustrates the time of the occurrence of different complications such as sepsis, acute respiratory distress syndrome (ARDS), acute cardiac injury, acute kidney injury and the secondary infection.