Objectives: Cytomegalovirus (CMV) is endemic worldwide, with marked differences in the seroprevalence rates between countries. The aim of this study was to analyze the seroprevalence of CMV infection in Croatia.
Methods:During a three year period (2013)(2014)(2015), 2438 consecutive serum samples collected from Croatian residents were tested for the presence of CMV IgM and IgG antibodies using enzyme-linked immunoassay. IgM/IgG positive samples were further tested for IgG avidity.
Results:The overall seroprevalence rates for CMV IgG and IgM antibodies were 74.4% and 4.3%, respectively. The IgG seroprevalence differed significantly between population groups: children/adolescents 54.6%, adult general population 77.2%, hemodialysis patients 91.4% (p<0.001). CMV seropositivity was strongly age-dependent with prevalence ranging from 53.0% in children less than 10 years to 93.8% in persons above 60 years (p<0.001). There was no difference in the prevalence between women with normal pregnancy and women with bad obstetric history. Gender and place of residence was not associated with CMV seropositivity.Using IgG avidity, current/recent primary CMV infection was confirmed by low/borderline avidity index (AI) in 46.7% participants, while in 53.3% high AI indicated CMV reactivation or reinfection. Primary infections were detected mainly in children and adolescents (83.2% and 70.5%), while reactivations/reinfections were common in persons older than 40 (77.0-100%). Reactivations/reinfections were most commonly detected in hemodialysis patients (92.3%). Logistic regression showed that older age and being on hemodialysis were significant predictors of CMV seropositivity.Conclusions: CMV is widespread in the Croatian population. Older age and being on hemodialysis appeared to be main risk factors for CMV infection.