Gergely Anna E, Bechet S, Simons de Fanti A, Le Guern AS, Goujon C, Pelicot M, Benabdel mounen G, Consigny PH.
J Travel Med 2011; 18:126-29.
The authors retrospectively analyzed hepatitis A virus (HAV) seroprevalence in travellers who had been born and lived at least 1 year in a developing country, wanted to travel to a hepatitis A endemic area, and consulted at the vaccination centre of the Institut Pasteur of Paris between September 1, 2008 and February 28, 2010. HAV seroprevalence was 82.4 % for a population of 646 immigrants for whom data were available. There was a significant difference according to the continent of origin (90 % in persons originating from Sub-Saharan Africa vs. 50% in those originating from Eastern Europe). More than 75 % of seronegative patients were less than 36 years old and less than the half had stayed more than 18 years in a developing country. Multivariate analysis showed that age, length of stay in the highly endemic country and continent of origin were independent factors for acquiring natural immunity against HAV.
Read the article
ECDC comment: Until very recently, migrants originating from developing countries were considered as naturally immune against HAV. However, the improvement of hygiene conditions and socioeconomic status has lead to a decrease of HAV seroprevalence in many developing countries. In particular, the age of acquisition shifted from childhood to adulthood. These results suggest the importance of broadening the screening of HAV immunological status in travelling immigrants in order to optimize the vaccination coverage of this population. If time is lacking, in view of these findings, the authors suggest HAV vaccination should be proposed to immigrants less than 36 years old.