[Evaluation of mass vaccination programmes: the experience of Hepatitis A in Catalonia].
BACKGROUND
The hepatitis A + B vaccination programme of preadolescents was introduced in 1998 in Catalonia. During the following years, one of the main objectives has been to quantify the reduction in the incidence of hepatitis A caused by the vaccination programme.


METHODS
A retrospective analysis applying the space-time scan statistic to reported incidence rates of hepatitis A was carried out in the counties of Catalonia from 1992 to 2007. The relative risk (RR) was calculated and the spatial autocorrelation was estimated using Moran's I statistic.


RESULTS
Six of the 7 space-time clusters identified by the scan statistic occurred in the pre-vaccine era (1992-1998) and only one in the post-vaccine era (1992-2007). In the first 10 four-weekly periods of the post-vaccine era (1999-2005) there was a significant reduction in the incidence of hepatitis A in Catalonia with respect to the pre-vaccine era (1992-1998) (p<0,01).


CONCLUSIONS
Moran's I statistic showed no pattern of global spatial dependence and was useful in detecting local clusters. These results corroborate previous studies that attributed most of the reduction in the incidence of hepatitis A in Catalonia to the effect of vaccination.
Oviedo
Manuel
M
Centro de Investigación Biomédica en Red en Epidemiología y Salud Pública (CIBERESP), España. manuel.oviedo@usc.es
Muñoz
Pilar
P
Domínguez
Angela
A
Carmona
Gloria
G
Batalla
Joan
J
Borras
Eva
E
Jansà
Josep Maria
JM
D006506:Hepatitis A / Q000517:prevention & control*; D022362:Hepatitis A Vaccines; D006801:Humans; D012189:Retrospective Studies; D013030:Spain; D014611:Vaccination / Q000706:statistics & numerical data*
D022362:Hepatitis A Vaccines