| marked decrease in the incidence and prevalence of hepatitis a in the basque country, spain, 1986-2004. | the aim of this study was to determine changes in the epidemiology of hepatitis a virus (hav) infection in the basque country, spain, and to evaluate their implications for vaccination strategies. a total of 1356 persons were enrolled in a study of the prevalence of anti-hav in 2004 and compared with two previous studies (1986-1987 and 1992). the selection method and the characteristics of the population were similar in the three studies. a marked decline in the seroprevalence in all age groups ... | 2007 | 16848926 |