Chapter 31 : A Seroepidemiological Study of Legionella pneumophila Antibodies in Spanish Patients: A 13-Year Retrospective Study

Abstract:

In Spain, where Legionnaires’ disease has been a notifiable disease since 1997, the incidence of Legionnaires’ disease has increased considerably in the past few years, but a large interregional variability still persists, similar to that existing in other countries. Seroepidemiological studies of Legionella pneumophila have usually been cross-sectional and have, almost always, been utilized to ascertain rates of exposure to the bacteria in apparently healthy populations or in different risk groups. This chapter outlines the underlying hypotheses of a retrospective study of patients with pneumonia. It also discusses the scope of the seroepidemiological study. The average prevalence of seropositivity to L. pneumophila antibodies in all the samples analyzed was 7.03%.The highest prevalence corresponded to the Balearic Islands (8.66%) and the lowest to Andalusia (5.95%), with Catalonia occupying an intermediate position (6.86%). A prospective study would permit the elimination of a possible bias in the selection of patients remitted to the laboratory for analysis. A study that also analyzes the evolution of the seroprevalence in an apparently healthy population would be useful in extrapolating the results to the general population.