Description and analysis of representative COVID-19 cases–A retrospective cohort study

Abstract

Background Most data on COVID-19 was collected in hospitalized cases. Much less is known about the spectrum of disease in entire populations. In this study, we examine a representative cohort of primarily symptomatic cases in an administrative district in Southern Germany. Methods We contacted all confirmed SARS-CoV-2 cases in the administrative district. Consenting participants answered a retrospective survey either via a telephone, electronically or via mail. Clinical and sociodemographic features were compared between hospitalized and non-hospitalized patients. Additionally, we assessed potential risk factors for hospitalization and time to hospitalization in a series of regression models. Results We included 897 participants in our study, 69% out of 1,305 total cases in the district with a mean age of 47 years (range 2–97), 51% of which were female and 47% had a pre-existing illness. The percentage of asymptomatic, mild, moderate (leading to hospital admission) and critical illness (requiring mechanical ventilation) was 54 patients (6%), 713 (79%), 97 (11%) and 16 (2%), respectively. Seventeen patients (2%) died. The most prevalent symptoms were fatigue (65%), cough (62%) and dysgeusia (60%). The risk factors for hospitalization included older age (OR 1.05 per year increase; 95% CI 1.04–1.07) preexisting lung conditions (OR 3.09; 95% CI 1.62–5.88). Female sex was a protective factor (OR 0.51; 95% CI 0.33–0.77). Conclusion This representative analysis of primarily symptomatic COVID-19 cases confirms age, male sex and preexisting lung conditions but not cardiovascular disease as risk factors for severe illness. Almost 80% of infection take a mild course, whereas 13% of patients suffer moderate to severe illness. Trial registration German Clinical Trials Register, DRKS00022926. URL: https://www.drks.de/drks_web/setLocale_EN.do

The effects of vaccination on the disease severity and factors for viral clearance and hospitalization in Omicron-infected patients: A retrospective observational cohort study from recent regional outbreaks in China

“…The two locations were geographically adjacent to each other, with the Han ethnics accounting for over 99% of the total population. Different from previous other overseas studies ( Herrmann et al., 2021 ) that only included symptomatic populations, this study enrolled all nucleic acid-positive cases in the regional outbreaks, including asymptomatic and mild patients. Informed consent was granted by all patients and the study protocol was approved by the Ethics Committee of the First Hospital of Quanzhou City (No.…”

The effects of vaccination on the disease severity and factors for viral clearance and hospitalization in Omicron-infected patients :A retrospective observational cohort study from recent regional outbreaks in China

“…They were divided into the Omicron group: 3,265 Omicron BA.2-infected patients in Quanzhou City, Fujian, China between March 13 and May 6, 2022; and the Delta group 14 : 226 Delta-infected patients (Delta B.1.167.2) in Putian City, Fujian, China from September 10 to October 20, 2021. Different from previous foreign studies 15 that only included symptomatic populations, this study enrolled all nucleic acid-positive cases in the regional outbreaks, including asymptomatic and mild patients. Informed consent was granted by all patients and the study protocol was approved by the Ethics Committee of the First Hospital of Quanzhou City (No.…”

Deaths during the first year of the COVID-19 pandemic: insights from regional patterns in Germany and Poland

“…As SARS-CoV-2 started spreading in the late 2019 and early 2020, it became clear that individuals particularly at risk of severe consequences of COVID-19 are older people and those with long-term cardiovascular [ 7 , 8 ] and pulmonary conditions [ 9 ] as well as those with generally weakened immune responses [ 10 ], in particular those suffering from cancer [ 11 ]. The ability of the virus to transmit through air via droplets and in aerosols makes infections more probable in contexts in which many people are gathered in small unventilated spaces.…”