Background and objective: Chlamydophila pneumoniae is an intracelular pathogen involved in the inflammatory pathogenesis of some chronic diseases with high prevalence. Infectivity is supposed to be high because the serologic patterns published are widely spread out all over the world. However, the prevalence in the Spanish adult population is unknown. Our goal was to assess the seroprevalence of specific IgG and IgA against C. pneumoniae in the general adult population performing an indirect immunofluorescence assay.
Material and method: 462 serum samples were analysed from subjects over 15 years of age in the general population in Valladolid.
Results: IgG 1:16 seroprevalence was 74.1% (95% confidence interval [CI], 69.7-78.6) and IgG 1:64 was 32.2% (95% CI, 27.6-36.8), whereas IgA 1:16 was 21.5% (95% CI, 17.7-25.4) and IgA 1:32 was 5.2% (95% CI, 3.3-7.2). Higher titles were found in men and with increasing age, specially for IgA (p < 0.05). Only 3.6% (95% CI, 1.9-5.3) and 0.7% (95% CI, 0.03-1.4) of subjects showed titles IgG 1:256 or 1:512, respectively. Almost one fourth showed a title 1:16 for both immunoglobulins.
Conclusions: Chlamydophila pneumoniae maintains a high seroprevalence of infection in the Spanish adult population.