Study on the correlation between molecular characteristics of SARS-CoV-2 and its epidemiology and clinical manifestations in Lu’an city

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic remains a major global public health threat, and ongoing viral mutations continue to complicate control efforts. To inform local prevention strategies, this study investigated the epidemiological and molecular characteristics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Lu'an city from 2020 to 2022, and analyzed their association with clinical outcomes. AIM: To analyze the molecular epidemiology and risk factors for severe COVID-19, and provide a scientific basis for guiding local epidemic prevention and control strategies. METHODS: Biological samples were collected from confirmed COVID-19 patients in Lu'an city between 2020 and 2022. Complete SARS-CoV-2 genomic sequences were obtained through sequencing. Epidemiological and clinical data were collected concurrently for each patient. Statistical analyses were conducted using IBM SPSS 29.0 software to assess risk factors associated with severe COVID-19. Viral genomic sequences were analyzed using MEGA software to characterize the molecular features of circulating SARS-CoV-2 strains. RESULTS: Sequencing identified the original SARS-CoV-2 strain in samples from 2020-2021, while the Omicron variant was detected in samples from 2022. The predominant clinical manifestations among patients were cough (67.03%) and fever (65.56%). Laboratory and imaging examinations revealed that 78.85% of infected patients exhibited abnormalities on chest computed tomography scans. Comprehensive analyses demonstrated that the temporal and spatial distribution of prevalent SARS-CoV-2 strains in Lu'an city was consistent with national trends in China. The presence of underlying comorbidities, including hypertension, diabetes, and liver injury, was significantly associated with progression to severe COVID-19. This risk showed little correlation with the specific SARS-CoV-2 variant type. CONCLUSION: The development of severe COVID-19 was predominantly associated with pre-existing comorbidities rather than with SARS-CoV-2 variant type. These findings provide evidence to inform targeted clinical management and public health planning for vulnerable populations.