Abstract
OBJECTIVE: To observe the clinical characteristics of mild and common COVID-19 patients infected with the Omicron variant, and to analyze related factors affecting the time to negative conversion of viral nucleic acid detection. METHODS: Clinical data of 1781 patients with coronavirus disease 2019 (COVID-19) admitted to a cabin hospital in Shanghai from April 12 to May 26, 2022, were retrospectively analyzed, including age, gender, height, weight, clinical symptoms, comorbid diseases, COVID-19 vaccination, treatment, and nucleic acid negative conversion time. Univariate and multivariate logistic regression analyses were used to analyze the influencing factors of nucleic acid negative conversion time. RESULTS: Among the 1781 patients, 995 were male and 786 were female, with a median age of 39 (30, 52) years. There were 727 patients (40.8%) with overweight and obesity [body mass index (BMI) > 24 kg/cm (2)) and 413 patients (23.2%) had comorbid diseases. 205 cases (11.5%) were not vaccinated while 1576 cases were vaccinated. There were 1233 cases (69.2%) with one or more symptoms. The main clinical symptoms were cough (60.3%), expectoration (50.4%) and fever (36.9%). 1444 cases (81.0%) were treated with Chinese medicine, 78 cases (4.4%) were treated with western medicine, 14 cases (0.8%) were treated with integrated Chinese and western medicine, and 245 cases (13.8%) did not receive any medical treatment. All patients improved and were discharged. The median nucleic acid negative conversion time was 10.3 (7.4, 12.4) d. Univariate and multivariate analysis showed that, age ≥ 60 years ( OR＝1.537, 95% CI: 1.116 - 2.115, P<0.01), BMI > 24 kg/cm (2) ( OR＝1.344, 95% CI: 1.106 - 1.634, P<0.01 ) and hypertension ( OR＝1.518, 95% CI: 1.094 - 2.106, P<0.05) were independent risk factors for prolonged nucleic acid negative conversion. COVID-19 vaccination ( OR=0.548, 95% CI: 0.398 - 0.755, P<0.01) was a protective factor, that is, vaccination shortened the time for the nucleic acid test to become negative. CONCLUSIONS: The symptoms of the Omicron variant infection were relatively mild and occult. Age ≥ 60 years old, comorbid hypertension, no vaccination and BMI > 24 kg/cm (2) are independent influencing factors for prolonged nucleic acid negative conversion.