Analysis of the epidemiology and clinical characteristics of Epstein–Barr virus infection

The Epstein-Barr virus (EBV) is responsible for a spectrum of human diseases and demonstrates a considerable prevalence among various populations. Advances in molecular epidemiological research have enhanced our comprehension of EBV-related pathologies. In this study, our objective was to examine the epidemiological profile and clinical features of EBV infection in Chongqing, China. We enrolled patients suspected of EBV-related diseases who were admitted to the First Affiliated Hospital of Chongqing Medical University between May 2013 and November 2022. Inclusion criteria were based on those who underwent EBV-specific immunofluorescence or plasma EBV-DNA testing. Among 13 584 inpatients, the overall seropositivity rates for EBNA-1-IgG, EBV-VCA-IgM, EBV-EA-IgG, EBV-EA-IgA, EBV-VCA-IgA, and EBV-DNA were 91.89%, 7.22%, 18.00%, 16.19%, 30.78%, and 18.00%, respectively. The seropositivity rate for EBNA-1-IgG steadily increased with age. The seropositivity rate for VCA-IgM, an indicator of acute EBV infection, was highest in patients aged 11-20 years at 26.41%, decreasing to 2%-6% in older patients. Additionally, among 205 outpatients, the EBV-DNA positivity rate was 14.15%. In 3670 individuals from health check-up centers, the seropositivity rates for EBV-EA-IgA and EBV-VCA-IgA were 11.96% and 28.09%, respectively, and the EBV-DNA positivity rate was 11.92%, all of which were lower than those in inpatients. Among the 762 EBV-DNA positive inpatients, adults aged 31-40 years were the least affected, with a seropositivity rate of 12.00%, which increased with age. The most common diseases associated with primary EBV infection were infectious mononucleosis (IM) (35.49%), followed by EBV infection (14.15%) and pneumonia (7.19%). The most common diseases associated with EBV reactivation were pneumonia (16.80%), nasopharyngeal carcinoma (NPC) (11.02%), and autoimmune diseases (7.04%). Patients with hemophagocytic lymphohistiocytosis (HLH) had the highest viral load, significantly higher than those with NPC, pneumonia, and liver cirrhosis. This large-scale retrospective study explores the epidemiological characteristics and disease spectrum of EBV infection across all age groups. The findings contribute to the improvement of diagnostic and management strategies for EBV infection.