Human Vaccines and Immunotherapeutics
Volume 11, Issue 1, 2015, Pages 192-197

Changes in the epidemiology of hepatitis A outbreaks 13 years after the introduction of a mass vaccination program (Conference Paper) (Open Access)

Martínez A. , Broner S. , Sala M.R. , Manzanares-Laya S. , Godoy P. , Planas C. , Minguell S. , Torner N. , Jané M. , Domínguez A.* , Alsedà M. , Arias C. , Barrabeig I. , Camps N. , Carol M. , Company M. , Ferràs J. , Ferrús G. , Parrón I. , Rovira A. , Torras R. , Olalla P. , Caylà J.
  • a Public Health Agency of Catalonia, Generalitat of Catalonia, Spain
  • b CIBER Epidemiologia Y Salud Pública, Carlos III Institute of Health, Madrid, Spain
  • c Public Health Agency of Barcelona, Barcelona, Spain
  • d Public Health Agency of Barcelona, Barcelona, Spain
  • e Public Health Agency of Catalonia, Generalitat of Catalonia, Spain
  • f Public Health Agency of Catalonia, Generalitat of Catalonia, Spain
  • g Public Health Agency of Catalonia, Generalitat of Catalonia, Spain
  • h Public Health Agency of Catalonia, Generalitat of Catalonia, Spain, CIBER Epidemiologia Y Salud Pública, Carlos III Institute of Health, Madrid, Spain, Department of Public Health, University of Barcelona, Barcelona, Spain
  • i Public Health Agency of Catalonia, Generalitat of Catalonia, Spain
  • j CIBER Epidemiologia Y Salud Pública, Carlos III Institute of Health, Madrid, Spain, Department of Public Health, University of Barcelona, Barcelona, Spain
  • k Public Health Agency of Catalonia, Spain
  • l Public Health Agency of Catalonia, Spain
  • m Public Health Agency of Catalonia, Spain
  • n Public Health Agency of Catalonia, Spain
  • o Public Health Agency of Catalonia, Spain
  • p Public Health Agency of Catalonia, Spain
  • q Public Health Agency of Catalonia, Spain
  • r Public Health Agency of Catalonia, Spain
  • s Public Health Agency of Catalonia, Spain
  • t Public Health Agency of Catalonia, Spain
  • u Public Health Agency of Catalonia, Spain
  • v Public Health Agency of Barcelona, CIBER Epidemiología Y Salud Pública, Spain
  • w Public Health Agency of Barcelona, CIBER Epidemiología Y Salud Pública, Spain

Abstract

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 106 persons-year) were reported in the pre-vaccination period and 258 outbreaks (rate of 2.82 per 106 persons-year) in the post-vaccination period. The rate of cases associated with outbreaks was 1.52 per 105 persons-year in the pre-vaccination period and 1.28 per 105 persons-year in the post-vaccination period. Hospitalization rates were 0.08 and 0.75 per 106 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 out-break-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. © 2015 Landes Bioscience.

Author Keywords

outbreak Mass immunization program Preventable fraction Hepatitis A Incidence rate Hospitalization

Index Keywords

hospitalization sexual behavior human middle aged hepatitis A statistics and numerical data Hepatitis A Vaccines procedures Young Adult Humans Adolescent male Spain preschool child female Infant risk factor Risk Factors Child, Preschool Incidence Disease Outbreaks epidemic Mass Vaccination mass immunization Hepatitis B Vaccines adult age Age Factors hepatitis B vaccine hepatitis A vaccine Child
Link
https://www.scopus.com/inward/record.uri?eid=2-s2.0-84949117671&doi=10.4161%2fhv.35861&partnerID=40&md5=8005a5a2d60125a6fe77cdad051b1d98
DOI: 10.4161/hv.35861
ISSN: 21645515
Cited by: 8
Original Language: English