If you wind up in the hospital with coronavirus, what might raise your chances of dying from the disease?
A new study offers some answers: being older; showing signs of sepsis; and having blood-clotting issues. To come to that conclusion, researchers analysed 191 adult patients with confirmed Covid-19 at two hospitals in Wuhan, China, the city where the worldwide outbreak began.
The scientists also found that hospitalised Covid-19 patients shed the virus for longer than expected, according to the study published in The Lancet journal. Viral shedding means that patients can still spread a virus.
The median duration of viral shedding was 20 days in survivors (ranging from eight to 37 days), and the virus was detectable until death in those who did not survive.
Extended viral shedding
However, factors such as the severe illness of the patients, and limited samples and genetic material for testing mean that the actual duration of viral shedding among patients remains unclear, the authors noted.
The study is the first to assess risk factors associated with severe disease and death in hospitalised Covid-19 patients, the researchers said. Of the 191 patients in the study, 137 were discharged and 54 died in the hospital.
"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 study co-lead author Bin Cao, from China-Japan Friendship Hospital and Capital Medical University, in 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," Cao said in a journal news release.
"We 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," Cao noted.
Poorer outcomes in older people
Other factors came into play when measuring death risk, the researchers noted.
"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 study co-author Dr Zhibo Liu, from Jinyintan Hospital, in 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 explained.
The median duration of fever in survivors was about 12 days – about the same as in those who died – but the cough may last for a long time, and 45% of survivors still had the cough when they were discharged from hospital, the researchers reported.
In survivors, shortness of breath ceased after about 13 days, but lasted until death in those who died, the findings showed.
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