Clinical Characteristics of COVID-19: Clinical Dynamics of Mild Severe Acute Respiratory Syndrome Coronavirus 2 Infection Detected by Early Active Surveillance.

BACKGROUND: There is limited information describing the presenting characteristics and dynamic clinical changes in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection diagnosed in the early phase of illness. This study is a case series of patients with coronavirus disease 2019 (COVID-19) admitted to 11 hospitals in Korea. METHODS: Patients with confirmed SARS-CoV-2 infection by positive polymerase chain reaction (PCR) testing of respiratory specimens by active surveillance that were finally discharged between February 20 and April 30, 2020 were included. Patients were classified into mild and non-mild groups on initial admission according to oxygen demand and Sequential Organ Failure Assessment score, and the mild group was followed up and subgrouped into non-aggravation and aggravation groups. RESULTS: A total of 161 patients with SARS-CoV2 infection were enrolled. Among the mild group of 136 patients, 11.7% of patients experienced clinical aggravation during hospitalization, but there was no initial clinical parameter on admission predicting their aggravation. Fever (odds ratio [OR], 4.56), thrombocytopenia (OR, 12.87), fever (OR, 27.22) and lactate dehydrogenase (LDH) > 300 U/L (OR, 18.35), and CRP > 1 mg/dL (OR, 11.31) significantly indicated aggravation in the 1st, 2nd, 3rd, and 4th 5-day periods, respectively. PCR positivity lasted for a median of 22 days and 32 days after the onset of illness in the non-aggravation and aggravation groups, respectively. CONCLUSION: Old age was associated with early severe presentation. Clinical aggravation among asymptomatic or mild patients could not be predicted initially but was heralded by fever and several laboratory markers during the clinical course.

Clinical Characteristics of Patients Who Contracted the SARS-CoV-2 Omicron Variant from an Outbreak in a Single Hospital.

There are few studies on the severity and prognosis of patients infected with the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) omicron variant. From January 11, 2022 to January 25, 2022, 181 patients were infected with the SARS-CoV-2 omicron variant in a single hospital in Korea. The initial clinical characteristics were investigated through the COVID-19 basic investigation form. Outcomes were reviewed using medical records. The median age of the patients was 57 years (range 1-90), and 95 patients (52.5%) were male. None were re-infected with SARS-CoV-2, and 127 (70.2%) were fully vaccinated (boosted or within 6 months after second vaccination). Forty-two patients (23.2%) were asymptomatic. Among symptomatic patients, the frequency of symptoms was as follows: cough (37.0%), sore throat (33.7%), and fever (30.4%). In terms of disease severity, 168 (92.8%) patients did not require supplemental oxygen, 6 (3.3%) required low-flow oxygen, 5 (2.8%) required high-flow oxygen, and 2 (1.1%) died. Four of the five individuals who required high-flow oxygen and the two who died were not vaccinated. Most of the patients who contracted the SARS-CoV-2 omicron variant exhibited mild clinical features; however, severe clinical features including mortality were encountered among individuals who were not vaccinated.