Evolution of EBV seroprevalence and primary infection age in a French hospital and a city laboratory network, 2000–2016

BACKGROUND According to rare studies, the age at EBV primary infection (PI) has recently risen in some developed countries. A later age at infection is generally considered a risk factor for severe EBV PI, although few studies exist on this subject. Our investigation aimed to determine whether EBV seroprevalence and EBV PI epidemiology have evolved in France, and to what extent age and infection intensity (regarding biological parameters) are correlated. METHODS AND FINDINGS We conducted a retrospective study of the following EBV serological tests databases: tests carried out at Grenoble University Hospital (2000-2016) (n = 53,553); and tests carried out by a network of city laboratories in Grenoble area (2008-2015) (n = 27,485). The hospital population showed a continuous, significant decrease in EBV seroprevalence over the studied period for patients aged 20 and over (p<0.01). The seroprevalence also decreased for different age classes (<10, 15-19, 20-30, and 30-40 years old) over the periods 2001-2005, 2006-2010, and 2011-2015. Consistently, the age at PI was significantly higher in the years 2008-2015 than in the years 2001-2007 (15.6±12.0 vs. 13.7±11.0; p = 0.03). The city laboratory population showed the same trend of decreasing seroprevalence (p = 0.06); no significant variations in age at PI were observed. The age at PI was positively correlated with ASAT, ALAT, γGT, and bilirubin blood levels (p<0.01) and negatively correlated with platelet counts (p<0.05). CONCLUSION In the last 15 years, the age at EBV PI has increased, whereas seroprevalence has decreased. Moreover, our findings confirm the positive correlation between age and biological abnormalities. Taken together, these results suggest that the incidence of severe EBV PI will increase in the future.