Table 1 Demographic characteristics of 28 COVID-19 patients in South Korea (N = 28). Variables n % Gender Male 15 53.6 Female 13 46.4 Age (y) 20–29 6 21.4 30–39 6 21.4 40–49 6 21.4 50–59 8 28.6 60–69 1 3.6 70–79 1 3.6 Nationality Korean 22 78.6 Chinese 6 21.4 Signs and Symptoms at onset (may be duplicated) Fever 9 32.1 Sore Throat 9 32.1 Cough or Sputum 5 17.9 Chills 5 17.9 Muscle ache 4 14.3 Generalized weakness 3 10.7 Headache 3 10.7 Asymptomatic infection or Unknown* 3 10.7 Pneumonia after admission Pneumonia 18 64.3 * Unknown: due to treatment with antibiotics and analgesics after surgery. COVID-19 = coronavirus disease 2019.