A study of the course of the wave of omicron infection in the Chinese capital Shanghai showed that the symptoms are mild in almost all cases. Risk factors are old age and underlying diseases.
The largest makeshift hospital in Shanghai, rebuilt from the National Convention & Exhibition Center, will be handed over on April 9, 2022 and will accommodate up to 50,000 beds. Photo: Xinhua.
The new study is the first to comprehensively describe the symptoms of patients with Covid-19 who do not have a severe course of the disease. This group of people accounted for more than 95 percent of all minor Covid cases in Shanghai. It shows that a comprehensive and precise targeting of medical resources to vulnerable populations can minimize the risk of overloading the regional health system.
Since the identification of the omicron variant in November 2021, this strain has become a major cause of infections worldwide, with cases growing exponentially in several countries. The high throughput of the variant has put an enormous strain on healthcare resources, although the vast majority of cases are not serious.
A large cohort study conducted by top Chinese epidemiologist Zhang Wenhong conducted during the Omicron epidemic by Huashan National Medical Center for Infectious Diseases at Fudan University and the Key Laboratory of Infectious Diseases and Biosafety in Shanghai between April 22 and 28, 2019. The study was conducted at four Shanghai hospitals on March 11 and May 3, 2022, describes the spectrum of clinical symptoms, risk factors for disease progression, and dynamic changes in viral load in initially less seriously infected omicron patients. The study was published Saturday in China CDC Weekly.
In Shanghai, 58,104 confirmed patients and 591,506 asymptomatic infections were reported by Sunday. According to the principle that all those in need are tested, those who test positive are quarantined, hospitalized or treated, all asymptomatic carriers, mild cases and average cases are treated centrally.
All 33,816 study participants were diagnosed with a minor Covid-19 infection upon admission to the hospital. They either had no underlying disease or only one underlying disease, but their health was stable. According to the study, in less severe cases, the most common symptoms were cough and mucus, followed by fatigue and fever. The average persistence of symptoms was seven days. The average virus spread time (VST) was six days. Age, comorbidities and initial symptoms were associated with longer VST, while full vaccination and revaccination were associated with shorter VST.
Throughout the cohort, 22 patients developed serious or critical infections. All belonged to a high-risk group of patients over 60 years of age with stable underlying disease (including cardiovascular disease, diabetes mellitus, lung disease, liver disease, cerebrovascular disease or kidney disease) or immune deficiency such as HIV infection.
The severity rates for all subjects and subjects in the risk group were 0.065 percent and 0.238 percent, respectively. The severity rate for the non-risk group was zero.
The study shows that older age, lack of vaccination and multiple underlying diseases increase the risk of serious or critical illness, which means that even among those who do not have a serious infection, there are still people who are susceptible to the omicron variant.
Therefore, precise prevention and control measures should be taken in vulnerable groups in order to reduce mortality in these groups and to reduce omicron damage to a lower level.
The study provides guidance for refining Covid-19 public health strategies to minimize the risk of overloading regional medical resources by accurately assessing Omicron’s major disease trajectories in different populations.
The study suggests that the rate of serious illnesses and deaths in vulnerable populations can be significantly and gradually reduced if protection measures are taken in a timely manner. These include full vaccination, adequate protection for vulnerable groups and immediate access to medical treatment immediately after infection.
When medical resources are fully and accurately targeted at a vulnerable population and an vulnerable group receives adequate primary health care, the distribution of medical resources will be optimized and the diagnosis and treatment of other diseases will not be lost due to the Covid-19 outbreak. , according to the study.