The Clinical Characteristics and Virus Shedding of Omicron Patients in a Shanghai Mobile Cabin Hospital

Abstract

Background Information about characteristics of Omicron-infected patients and estimation of risk factors for the duration of viral shedding were unclear. Methods This retrospective study included asymptomatic patients and patients with mild symptoms, who were infected with Omicron and hospitalized in a Shanghai mobile cabin hospital. The clinical characteristics of those patients were summarized, and the influencing factors of severe acute respiratory syndrome coronavirus 2 virus shedding were explored. Results Multivariate logistic regression analysis indicated that comorbidities (odds ratio [OR], 1.991; 95% confidence interval [CI], 1.365–2.904; P = 0.000), 2 doses of vaccines (OR, 2.421; 95% CI, 1.636–3.584; P = 0.000), 3 doses of vaccine/booster shots (OR, 3.797; 95% CI, 2.607–5.529; P = 0.000), and virus shedding time (OR, 1.078; 95% CI, 1.053–1.103; P = 0.000) were associated with increased odds of mild symptoms in Omicron patients, whereas age (OR, 0.951; 95% CI, 0.940–0.963; P = 0.000) was associated with a reduced risk of mild symptoms. The median length of virus ribonucleic acid shedding time was 10 days. Being male (OR, 1.868; 95% CI, 1.488–2.345; P < 0.001), age (OR, 1.018; 95% CI, 1.008–1.028; P < 0.001), and a diagnosis of mild symptoms (OR, 1.508; 95% CI, 1.244–1.895; P < 0.001) were risk factors of prolonged shedding time in multivariate regression analysis. The cycle threshold values of nucleocapsid protein and open reading frame 1ab genes in Omicron patients with virus shedding time ≤10 days are significantly different from that in patients with virus shedding time >20 days (P < 0.001). Conclusions Being male, being older, and having a mild case were all risk factors for prolonged virus shedding time, and patients with high viral load may have long virus shedding time. Patients who are young, have complications, and have been vaccinated with 2 or 3 doses/enhanced vaccines with long virus shedding time increased the risk of clinical symptoms.