The seroprevalence of cytomegalovirus infection in Belgium anno 2002 and 2006: a comparative analysis with hepatitis A virus seroprevalence

Abstract

Cytomegalovirus (CMV) infection is endemic worldwide but its seroprevalence varies widely. The goal of this study was to estimate the age-specific seroprevalence of CMV infection in Belgium based on two cross-sectional serological datasets from 2002 and 2006. The seroprevalence was estimated relying on diagnostic test results based on cut-off values pre-specified by the manufacturers of the tests as well as relying on mixture models applied to continuous pathogen-specific immunoglobulin G antibody titre concentrations. The age-specific seroprevalence of hepatitis A virus (HAV), based on three Belgian cross-sectional serological datasets from 1993, 2002 and 2006, was used as a comparator since individuals acquire lifelong immunity upon recovery, implying an increasing seroprevalence with age. The age group weighted overall CMV seroprevalence derived from the mixture model was 32% (95% confidence interval (CI) 31-34%) in 2002 and 31% (95% CI 30-32%) in 2006. We demonstrated that CMV epidemiology differs from the immunizing infection HAV. This was the first large-scale study of CMV and HAV serial datasets in Belgium, estimating seroprevalence specified by age and birth cohort.

Keywords: Cytomegalovirus; estimating age and birth cohort-specific seroprevalence; hepatitis A virus; mixture modelling; seroincidence.

Fig. 1.

Cytomegalovirus seroprevalence in function of age in 2002 and 2006 estimated by using splines and fixed cut-offs and by the mixture model. Note: Age groups consist of 1 year in the spline fit and 4 years in the mixture model.

Fig. 2.

Cytomegalovirus seroprevalence by birth cohort in 2002 and 2006 estimated by splines and fixed cut-offs and by the mixture models (rows) for the total population, females and males (columns). Note: Birth cohorts consist of 1 year in the spline fit and 4 years with in the mixture model.

Fig. 3.

Cytomegalovirus seroincidence by birth cohort in 2006 compared with 2002 estimated using splines and fixed cut-offs and by the mixture models (rows) for the total population, males and females (columns). Note: Birth cohorts consist of 1 year in the spline fit and 4 years in the mixture model.

Fig. 4.

Seroprevalence of hepatitis A virus antibodies as a function of age and birth cohorts in 1993, 2002 and 2006 resulting from primary infection or vaccination using splines and the fixed cut-offs.

Fig. 5.

Seroincidence of hepatitis A virus antibodies per birth cohort comparing 2002–1993, 2006–1993 and 2006–2002 estimated using splines and the fixed cut-offs.