Post-pandemic SARS-CoV-2 Antigen Detection and Clinical Patterns among Patients in a Tertiary Hospital in North Central Nigeria

Background: The emergence of the Coronavirus Disease 2019 (COVID-19) pandemic has posed a major public health challenge globally. Early diagnosis of infectious diseases such as COVID-19 is essential in limiting the spread and associated complications. Also, understanding the local disease dynamics, including its risk factors and clinical patterns, is critical for guiding preventive and control measures. Objective: This study aimed to detect SARS-CoV-2 antigen in nasopharyngeal swabs from patients and to determine the associated risk factors and clinical patterns of infection among patients attending the Federal Medical Centre (FMC), Keffi, Nasarawa State, Nigeria. Methods: A cross-sectional study was conducted between March and July 2023, recruiting 400 patients who presented with symptoms suggestive of COVID-19. Nasopharyngeal swab samples were collected and analyzed for SARS-CoV-2 antigen using the STANDARD Q COVID-19 Ag Test (SD BIOSENSOR, Inc, Korea) rapid test kit following the manufacturer’s instructions. Socio-demographic and clinical data, including age, sex, and symptoms, were collected using a questionnaire after consent was obtained. Results were analyzed using SPSS Version 25.0 (IBM Corp., USA). Descriptive statistics, Chi-square test and Fisher’s exact test were used to summarise and determine the association between categorical variables with a significance level of P < 0.05. Results: Out of the 400 patients tested, 4 (1.0%) (95% CL: 0.3% - 1.97%) were positive. There was no statistically significant difference with gender (P > 0.05). However, a borderline significant association with infection status (P = 0.05) was observed for age, with higher prevalence in older age groups, suggesting vulnerability. Cough (P < 0.05), loss of smell (P < 0.05), and nasal congestion (P < 0.05) were significant. No significant association was observed for fever, loss of taste, or shortness of breath, occupation and hand hygiene (P > 0.05). Additionally, SARS-CoV-2 antigen positivity was significantly associated with lack of vaccination and the use of a facemask (P < 0.05). Conclusion: The outcome of this study suggests a reduction in the number of COVID-19 infection cases among patients in the study area. Age was identified as a significant risk factor. Though the RDT method used and sample size may limit categorical conclusions, the RDT facilitates rapid detection, which is cost-effective and timely. It serves as an alternative for mass testing and public health surveillance.