Clinical characteristics of 1139 mild cases of the SARS‐CoV‐2 Omicron variant infected patients in Shanghai

Abstract

In March 2022, the Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) surged during the Coronavirus Disease 2019 (COVID‐19) pandemic in Shanghai, but over 90% of patients were mild. This study included 1139 COVID‐19 patients mildly infected with the Omicron variant of SARS‐CoV‐2 in Shanghai from May 1 to 10, 2022, aiming to clarify the demographic characteristics and clinical symptoms of patients with mild Omicron infection. The clinical phenotypes of Omicron infection were identified by model‐based cluster analysis to explore the features of different clusters. The median age of the patients was 41.0 years [IQR: 31.0–52.0 years] and 73.0% were male. The top three clinical manifestations are cough (57.5%), expectoration (48.3%), and nasal congestion and runny nose (43.4%). The prevalence of nasal congestion and runny nose varied significantly across the doses of vaccinations, with 23.1% in the unvaccinated population and 30%, 45.9%, and 44.3% in the 1‐dose, 2‐dose and 3‐dose vaccinated populations, respectively. In addition, there were significant differences for fever (23.1%, 26.0%, 28.6%, 18.4%), head and body heaviness (15.4%, 14.0%, 26.7%, 22.4%), and loss of appetite (25.6%, 30.0%, 33.6%, 27.7%). The unvaccinated population had a lower incidence of symptoms than the vaccinated population. Cluster analysis revealed that all four clusters had multisystemic symptoms and were dominated by both general and respiratory symptoms. The more severe the degree of the symptoms was, the higher the prevalence of multisystemic symptoms will be. The Omicron variant produced a lower incidence of symptoms in mildly infected patients than previous SARS‐CoV‐2 variants, but the clinical symptoms caused by the Omicron variant are more complex, so that it needs to be differentiated from influenza.

Comparative analysis of symptom profile and risk of death associated with infection by SARS‐CoV‐2 and its variants in Hong Kong

“…We found a high prevalence of upper respiratory tract infections among the predominant omicron cases in the fifth wave with differences by vaccination status. This is consistent with other studies 10,19,20,27,28 . Furthermore, we found a much lower incidence of “loss of taste and smell,” a test‐triggering symptom in the past, 29,30 in the BA.2 cohort.…”

“…This is consistent with other studies. 10,19,20,27,28 Furthermore, we found a much lower incidence of "loss of taste and smell," a test-triggering symptom in the past, 29,30 in the BA.2 cohort. These altogether increase the difficulty to distinguish COVID-19 with symptom-based testing algorithms.…”

“…As of March 26, 2023, weekly hospitalizations by COVID‐19 exceeded that of influenza by 13‐fold in the United Kingdom 7 . Though symptoms triggered by respiratory illnesses are generally alike, 8 the persistent clinical sequelae after the acute phase of infection 9 and the complexity of symptoms added by the omicron variant 10 highlight the need to differentiate COVID‐19 from other respiratory diseases. While the circulating omicron variant may induce less severe symptoms than its preceding counterparts, 11 this benignity can be counterbalanced by an increased incidence of infection disrupting society via sickness.…”

Workplace Measures Against COVID-19 and Mistreatment in the Workplace Among Japanese Employees

“…This result indicates that not all employees were actively and positively involved in daily temperature measurements. The reasons for this could be that employees felt that instructions from the company outside of working hours are stressful (especially on busy mornings) or a feeling of futility that the body temperature data are not being used to any great extent because the frequency of fever caused by BA.5 Omicron variants is not high 30,31 . For these employees, daily temperature measurement could be regarded as mistreatment.…”

Clinical characteristics and prognosis of 1589 omicron patients with cardiovascular disease in Shanghai

“…Similarly, a recent study showed that clinical symptoms of patients with Omicron infection were more complex and needed to be differentiated from influenza. 6 The median LOS was 5 days (IQR, 4–7). Distribution curve in Fig.…”