Covid-19 Risk Factors, Clinical Course and Patient Mortality in Wuhan China

by | Mar 30, 2020 | 2020, COVID-19, Lung Health, Respiratory Health

Written by Joyce Smith, BS. This study details the risk factors for Covid-19 infection, including patient mortality, clinical course of illness and viral shedding.

In December of 2019, Wuhan, China experienced an outbreak of a pneumonia of unknown cause. By January 7th, Chinese scientists had isolated from patients with virus-infected pneumonia a novel coronavirus that became known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; previously known as 2019-nCoV) 1,2. In February of 2020, the World Health Organization (WHO) designated this novel coronavirus “coronavirus disease 2019” or “COVID-19” 3.The likely outbreak origin was an animal from a large seafood market in Wuhan that also traded in wild animals. Very rapid and efficient person-person transmission followed.

This retrospective , multicenter cohort  study 4 details the mortality risk factors and outlines the clinical course of the illness of 191 patients admitted to two Wuhan hospitals between December 29, 2019 (when admission began) and January 31, 2020, of whom 137 were discharged and 54 died in hospital. SARS-CoV-2 symptoms encompassed a wide spectrum of symptoms from mild upper respiratory to severe pneumonia and respiratory failure and death 5-7. Some case series have been published and many patients in these series were still hospitalized at the time of this study’s publication.

Details of the 191 patients are as follows: 54 died in hospital, 137 were discharged, ages ranged from 18-87 years (mean age 56 years), and most were males. Almost 50 % had comorbidities with 30 % hypertension the most common, followed by diabetes (19%) and heart disease (8%). Common symptoms were fever and cough followed by sputum production and fatigue; 40 % had lymphocytopenia. Treatments included antibiotics, antivirals, systematic corticosteroid, and intravenous immunoglobulin. The risk of in-hospital deaths and organ failure increased with increasing age. Analysis revealed that an increasing odds of in-hospital death was associated with older age (odds ratio 1·10,95% CI 1·03–1·17; p=0·0043), a higher Sequential Organ Failure Assessment (SOFA) score (5·65, 2·61–12·23; p<0·0001, and d-dimer levels greater than 1·0 μg/mL (18·42, 2·64–128·55; p=0·0033) on admission.  (D -dimer is a fibrin degradation product – a small protein fragment present in the blood after a blood clot is degraded by fibrinolysis and used in the diagnosis of the blood disorder disseminated intravascular coagulation). Median duration of viral shedding was 20 days (IQR 17–24) in survivors, but in non-survivors, SARS-CoV-2 was detectable until death. The longest observed duration of viral shedding in survivors was 37 days.

Older age, elevated d-dimer levels, and a high SOFA score could help clinicians identify early stage COVID-19 patients who have poor prognosis. The evidence of prolonged viral shedding supports a policy of “social isolation” as a strategy for containment of infected patients and intensifies the need to develop future effective antiviral interventions.

Source: Zhou, Fei, Ting Yu, Ronghui Du, Guohui Fan, Ying Liu, Zhibo Liu, Jie Xiang et al. “Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study.” The Lancet (2020).

© 2020 Elsevier Ltd. All rights reserved.

Posted March 30, 2020.

Joyce Smith, BS, is a degreed laboratory technologist. She received her bachelor of arts with a major in Chemistry and a minor in Biology from  the University of Saskatchewan and her internship through the University of Saskatchewan College of Medicine and the Royal University Hospital in Saskatoon, Saskatchewan. She currently resides in Bloomingdale, IL.

References:

  1. Phelan AL, Katz R, Gostin LO. The Novel Coronavirus Originating in Wuhan, China: Challenges for Global Health Governance. Jama. 2020.
  2. Gorbalenya AE. Severe acute respiratory syndrome-related coronavirus–The species and its viruses, a statement of the Coronavirus Study Group. BioRxiv. 2020.
  3. Chan J, Ng C, Chan Y, et al. Short term outcome and risk factors for adverse clinical outcomes in adults with severe acute respiratory syndrome (SARS). Thorax. 2003;58(8):686-689.
  4. Chen N, Zhou M, Dong X, et al. Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study. The Lancet. 2020;395(10223):507-513.
  5. Li Q, Guan X, Wu P, et al. Early transmission dynamics in Wuhan, China, of novel coronavirus–infected pneumonia. New England Journal of Medicine. 2020.
  6. Huang C, Wang Y, Li X, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. The Lancet. 2020;395(10223):497-506.
  7. Wang D, Hu B, Hu C, et al. Clinical Characteristics of 138 Hospitalized Patients With 2019 Novel Coronavirus-Infected Pneumonia in Wuhan, China. Jama. 2020.