Hepatitis A immunity and region-of-origin in a Swiss prison

Purpose - The environmental and demographic characteristics of closed institutions, particularly prisons, precipitate morbidity during hepatitis A virus (HAV) outbreaks. Given the high prevalence of chronic liver disease and other risk factors in the prison setting, the purpose of this paper is to examine HAV-immunity and its associated factors in this population. Design/methodology/approach - The cross-sectional study was conducted in 2009: a serology screening for HAV IgG was carried out among 116 inmates in Switzerland's largest pre-trial prison. Other participant characteristics were collected through a structured face-to-face questionnaire with a physician. Findings - In terms of significant demographics, Africa (53.5 percent) and the Balkans/Eastern Europe (36.2 percent) were the main regions of origin; a minority of inmates were from Western Europe (6.9 percent), Latin America (2.6 percent) or Asia (0.9 percent). The authors identified hepatitis A antibody-negative serology (lack of immunity) in five out of 116 prisoners (4.3 percent, 95 percent CI 1.4-9.7). Among participants of European origin alone, five out of 50 inmates were hepatitis A antibody-negative (10 percent, 95 percent CI 3.3-21.8), whereas the 66 inmates from other all continents were hepatitis A antibody-positive (immune) (p=0.026). Originality/value - In this prison population composed of mostly African migrants, hepatitis A immunity was high. This reaffirms that region of origin is highly associated with childhood immunity against HAV. HAV vaccination should take into account a patient's area of origin and his/her risk factors for systemic complications, if ever infected. This targeted strategy would offer herd immunity, and seek out the most vulnerable individuals who are potentially at risk of new exposure in this precarious setting.