| hepatitis a immunity in the district of aveiro (portugal): an eleven-year surveillance study (2002-2012). | hepatitis a is a common viral liver disease and brings serious health and economic problems as its epidemiologic pattern changes over time. national serosurveys from developed countries have indicated a decline in hav (hepatitis a virus) seroprevalence over time due to the improvement of economic and sanitation levels. the hepatitis a virus (hav) immunity rate was surveyed throughout an eleven-year period by sex and age group in aveiro district. in this retrospective study, blood samples from pa ... | 2014 | 24638206 |