Clinical Course and Outcomes of Patients with Severe Acute Respiratory Syndrome Coronavirus 2 Infection: a Preliminary Report of the First 28 Patients from the Korean Cohort Study on COVID-19

Abstract

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected pneumonia emerged in Wuhan, China in December 2019. In this retrospective multicenter study, we investigated the clinical course and outcomes of novel coronavirus disease 2019 (COVID-19) from early cases in Republic of Korea.

Methods: All of the cases confirmed by real time polymerase chain reaction were enrolled from the 1st to the 28th patient nationwide. Clinical data were collected and analyzed for changes in clinical severity including laboratory, radiological, and virologic dynamics during the progression of illness.

Results: The median age was 40 years (range, 20-73 years) and 15 (53.6%) patients were male. The most common symptoms were cough (28.6%) and sore throat (28.6%), followed by fever (25.0%). Diarrhea was not common (10.7%). Two patients had no symptoms. Initial chest X-ray (CXR) showed infiltration in 46.4% of the patients, but computed tomography scan confirmed pneumonia in 88.9% (16/18) of the patients. Six patients (21.4%) required supplemental oxygen therapy, but no one needed mechanical ventilation. Lymphopenia was more common in severe cases. Higher level of C-reactive protein and worsening of chest radiographic score was observed during the 5-7 day period after symptom onset. Viral shedding was high from day 1 of illness, especially from the upper respiratory tract (URT).

Conclusion: The prodromal symptoms of COVID-19 were mild and most patients did not have limitations of daily activity. Viral shedding from URT was high from the prodromal phase. Radiological pneumonia was common from the early days of illness, but it was frequently not evident in simple CXR. These findings could be plausible explanations for the easy and rapid spread of SARS-CoV-2 in the community.

Keywords: COVID-19; Cohort Study; Prognosis; Republic of Korea; SARS-CoV-2; Viral Pneumonia.

Fig. 1. Changes in laboratory data according to severity over time in 28 patients with COVID-19. Changes in peripheral blood neutrophil counts is shown in (A) and (B) according to requirement of O₂ therapy, respectively. Changes in peripheral blood lymphocyte counts is shown in (C) and (D). Changes in CRP is shown in (E) and (F).

COVID-19 = coronavirus disease 2019, CRP = C-reactive protein, Pt = patient.

Fig. 2. Changes in SARS-CoV-2 Ct value of RT-PCR in respiratory specimens and radiologic features over time. Changes of Ct value of SARS-CoV-2 RNA (envelope gene, E) in nasopharyngeal with or without oropharyngeal specimen is shown in (A) in 9 patients with COVID-19. Changes of Ct value of SARS-CoV-2 RNA (E) in lower respiratory specimen (expectorate sputum) is shown in (B). Progression of pneumonia in 28 patients is shown in (C). Each lung was divided into the upper, middle, and lower zones, and infiltrates on each zone were scored from 0 to 4 (maximum CXR score, 24).

SARS-CoV-2 = severe acute respiratory syndrome coronavirus 2, Ct = cycle threshold, RT-PCR = real time reverse transcription polymerase chain reaction, COVID-19 = coronavirus disease 2019, Pt = patient, CXR = chest X-ray.