Changes in the epidemiology of hepatitis A outbreaks 13 years after the introduction of a mass vaccination program
Por:
Martinez, A, Broner, S, Sala, MR, Manzanares-Laya, S, Godoy, P, Planas, C, Minguell, S, Torner, N, Jane, M, Dominguez, A
Publicada:
1 ene 2015
Resumen:
A hepatitis A+B vaccine vaccination program of 12-year-olds was introduced in Catalonia in 1998. The aim of this study was to investigate the evolution of hepatitis A outbreaks in Catalonia and estimate the preventable fraction of cases associated with outbreaks as a measure of the impact of the vaccination program. Hepatitis A outbreaks reported to the Health Department between 1991 and 2012 were analyzed. The incidence rates of outbreaks, outbreak-associated cases and hospitalizations were calculated. The preventable fraction (PF) and 95% confidence intervals (CI) were estimated for the whole study period (pre-vaccination and post-vaccination) and the post-vaccination period.
One-hundred-eight (108) outbreaks (rate of 2.21 per 10(6) persons-year) were reported in the pre-vaccination period and 258 outbreaks (rate of 2.82 per 10(6) persons-year) in the post-vaccination period. The rate of cases associated with outbreaks was 1.52 per 10(5) persons-year in the pre-vaccination period and 1.28 per 10(5) persons-year in the post-vaccination period. Hospitalization rates were 0.08 and 0.75 per 10(6) persons-year, respectively. The number of person-to-person outbreaks whose index case was a school contact decreased in the post-vaccination period (aOR 2.72; 95%CI 1.35-5.48), but outbreaks whose index case was a man who has sex with men (MSM) or an immigrant increased. The PF of all outbreak-associated cases was 6.46% (95%CI 3.11-9.82) and the highest PF was in the 15-24 years age group (42.53%; 95%CI 29.30-55.75). In the 0-4 years age group, the PF was 18.35% (95%CI 9.59-27.11), suggesting a protective herd effect in unvaccinated subjects. Vaccination of immigrants traveling to endemic countries and MSM should be reinforced.
Filiaciones:
Martinez, A:
Generalitat Catalonia, Publ Hlth Agcy Catalonia, Catalonia, Spain
Broner, S:
Carlos III Inst Hlth, CIBER Epidemiol & Salud Publ, Madrid, Spain
Sala, MR:
Generalitat Catalonia, Publ Hlth Agcy Catalonia, Catalonia, Spain
Manzanares-Laya, S:
Publ Hlth Agcy Barcelona, Barcelona, Spain
Godoy, P:
Generalitat Catalonia, Publ Hlth Agcy Catalonia, Catalonia, Spain
Planas, C:
Generalitat Catalonia, Publ Hlth Agcy Catalonia, Catalonia, Spain
Minguell, S:
Generalitat Catalonia, Publ Hlth Agcy Catalonia, Catalonia, Spain
Torner, N:
Generalitat Catalonia, Publ Hlth Agcy Catalonia, Catalonia, Spain
Carlos III Inst Hlth, CIBER Epidemiol & Salud Publ, Madrid, Spain
Univ Barcelona, Dept Publ Hlth, Barcelona, Spain
Jane, M:
Generalitat Catalonia, Publ Hlth Agcy Catalonia, Catalonia, Spain
Dominguez, A:
Carlos III Inst Hlth, CIBER Epidemiol & Salud Publ, Madrid, Spain
Univ Barcelona, Dept Publ Hlth, Barcelona, Spain
Green Published, Bronze
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