| epidemiology and prevalence of seropositivity against borrelia burgdorferi antigen in la rioja, spain. | the aim of this study was to acquire a better knowledge of the epidemiology of lyme disease. a seroepidemiologic study was made by evaluating the different levels of antibodies to borrelia burgdorferi in a five hundred serum representative sample of a population from the province of la rioja, spain. samples were randomly selected and stratified to take into account sex, age, rural or urban residence, and geographical area. all subjects included in the study were asked to fill out a questionnaire ... | 1992 | 1631381 |