BACKGROUND: The presence in serum of antibodies to viral antigens is generally considered a well-defined marker of past @entity281 or vaccination. However, analyses of serological data that use a cut-off value to classify individuals as seropositive are prone to misclassification bias, in particular when studying infections with a weak serological response, such as the sexually transmitted @entity1082 ). METHODS: We analyzed the serological concentrations of HPV @entity1799 (HPV16) antibodies in the general Dutch population in 2006-2007, before the introduction of mass vaccination against HPV. We used a 2-component mixture model to represent @entity1 who were seronegative or seropositive for @entity1799 . Component densities were assumed to be log-normally distributed, with parameters possibly dependent on sex. The age-dependent mixing proportions were smoothed using penalized splines to obtain a flexible seroprevalence profile. RESULTS: Our results suggest that @entity1799 seropositivity is associated with higher antibody concentrations in @entity1 as compared with @entity1 . Seroprevalence shows an increase starting from adolescence in @entity1 and @entity1 alike, coinciding with the age of sexual debut. Seroprevalence stabilizes in @entity1 around age 40, whereas it has a decreasing trend from age 50 onwards in @entity1 . Analyses that rely on a cut-off value to classify @entity1 as seropositive yield substantially different seroprevalence profiles, leading to a qualitatively different interpretation of @entity1799 @entity281 dynamics. CONCLUSIONS: Our results provide a benchmark for examining the effect of @entity1799 vaccination in future serological surveys. Our method may prove useful for estimating seroprevalence of other infections with a weak serological response.

Estimating Seroprevalence of XXXX Using a Mixture Model with Smoothed Age-dependent Mixing Proportions.

@entity1 :: ('9606', 'Species') :: ['women', 'persons', 'men'] @entity281 :: ('MESH:D007239', 'Disease') :: ['infection'] @entity1799 :: ('333760', 'Species') :: ['HPV16', 'type 16'] @entity1082 :: ('10566', 'Species') :: ['human papillomavirus (HPV']
@entity1799 :: (333760,Species) :: ['Human Papillomavirus Type 16']
