Abstract
BACKGROUND: Patients with COVID-19 exhibited a variety of clinical characteristics. However, there is currently insufficient evidence to delineate the differences in clinical symptomatology between primary infection and reinfection. This study aims to compare the clinical symptom characteristics between primary infection and reinfection during COVID-19. METHODS: This research utilized a convenience sampling method to gather survey data from Chinese individuals aged 18 to 60 years across China. Questionnaire assessments were conducted to collect data on general demographic and clinical information during the COVID-19 pandemic in China. The collected data were analyzed using IBM SPSS 26.0 software. RESULTS: This study analyzed 1156 patients. During second infection, the frequency of fever, painful muscles, ageusia or anosmia, headache, back pain, feeling hot and cold alternately, general tiredness, tingling extremities, heavy arms or legs, and chest pain symptoms were significantly lower. However, the rate of sneezing, runny nose, and stuffy nose were significantly higher (p < 0.05). The proportion of patients with symptoms lasting 3-4 weeks and a body temperature of 38.1-41.0°C was significantly lower during second infection (p < 0.05). The cases infected with COVID-19 for the second time had a higher proportion of nurses and a higher proportion of individuals who received one or two doses of the COVID-19 vaccine (p < 0.05). CONCLUSIONS: The analysis of COVID-19 cases showed significant differences in demographic and clinical symptom characteristics between the first-time and second-time positive populations. This understanding can help guide changes in management strategies.