Epidemiological, clinical, and virological characteristics of 465 hospitalized cases of coronavirus disease 2019 (COVID-19) from Zhejiang province in China

Abstract

Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the associated coronavirus disease (COVID-19) have spread throughout China. Previous studies predominantly focused on its place of origin, Wuhan, causing over estimation of the disease severity due to selection bias. We analyzed 465 confirmed cases in Zhejiang province to determine the epidemiological, clinical, and virological characteristics of COVID-19.

Methods: Epidemiological, demographic, clinical, laboratory, and management data from qRT-PCR confirmed COVID-19 patients from January 17, 2020, to January 31, 2020, were collected, followed by multivariate logistic regression analysis for independent predictors of severe/critical-type COVID-19 and bioinformatic analysis for features of SARS-CoV-2 from Zhejiang province.

Results: Among 465 COVID-19 patients, median age was 45 years, while hypertension, diabetes, and chronic liver disease were the most common comorbidities. History of exposure to the epidemic area was present in 170 (36.56%) and 185 (39.78%) patients were clustered in 77 families. Severe/critical-type of COVID-19 developed in 49 (10.54%) patients. Fever and cough were the most common symptoms, while diarrhea/vomiting was reported in 58 (12.47%) patients. Multivariate analysis revealed eight risk factors for severe/critical COVID-19. Glucocorticoids and antibiotics were administered to 60 (12.90%) and 218(46.88%) patients, respectively. Bioinformatics showed four single amino acid mutations and one amino acid position loss in SARS-CoV-2 from Zhejiang province, with more similarity to humans than to viruses.

Conclusions: SARS-CoV-2 showed virological mutations and more human transmission in Zhejiang province, indicating considerable epidemiological and clinical changes. Caution in glucocorticoid and antibiotics use is advisable.

Keywords: Zhejiang province; coronavirus disease 2019 (COVID-19); risk factors; severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Figure 1

Chest computed tomography (CT) images of three patients diagnosed with COVID‐19. (A) Non‐contrast axial CT of a 30‐year‐old man diagnosed with COVID‐19 pneumonia (mild type), in the lung window, demonstrates a solid nodule in the left lower lobe. The bronchus is visible as an air bronchogram. (B) Non‐contrast axial CT of a 48‐year‐old man diagnosed with COVID‐19 pneumonia (severe type) and ARDS, in the lung window, demonstrates peripheral and multiple ground‐glass opacities (GGO). The pulmonary architecture, including vasculature and bronchi, can be still seen. (C‐D) Non‐contrast axial CT of a 40‐year‐old man diagnosed with COVID‐19 pneumonia (severe type), in the lung window, demonstrates bilateral subpleural consolidation and opacities in the two lower lobes, more densely consolidated on the right. CT lung of the same patient one week after treatment, in the lung window demonstrates that the lung lesions were significantly absorbed

Figure 2

Viral sequencing, phylogenetic analysis, and synonymous codon usage analysis of ZJ01. (A) Due to an accident during sequencing, the ORF1ab segment of the ZJ01 sample lost a 0.5 k base during this study. (B) The amino acid sequence alignment of ZJ01 shows that it is nearly identical with the Wuhan SARS‐CoV‐2 in S protein. (C) A three‐dimensional reconstruction model of the S protein clearly shows where the mutations are located. (D) Maximum likelihood genealogy shows the evolution of SARS‐CoV‐2. It reveals the relationship between SARS‐CoV‐2 and other coronaviruses. (E) Results from the RSCU heat map demonstrate that the RSCU of ZJ01 appears to be moving away from its relatives