%0 Journal Article %J Euro Surveill %D 2018 %T Hepatitis A outbreak disproportionately affecting men who have sex with men (MSM) in the European Union and European Economic Area, June 2016 to May 2017. %A Patricia Ndumbi %A Gudrun S Freidl %A Christopher J Williams %A Otilia Mårdh %A Carmen Varela %A Ana Avellón %A Ingrid Friesema %A Vennema, Harry %A Kazim Beebeejaun %A Siew Lin Ngui %A Michael Edelstein %A Alison Smith-Palmer %A Niamh Murphy %A Jonathan Dean %A Mirko Faber %A Jürgen Wenzel %A Mia Kontio %A Luise Müller %A Sofie Elisabeth Midgley %A Lena Sundqvist %A Ederth, Josefine Lundberg %A Anne-Marie Roque-Afonso %A Elisabeth Couturier %A Sofieke Klamer %A Javiera Rebolledo %A Vanessa Suin %A Stephan W Aberle %A Schmid, Daniela %A Rita De Sousa %A Augusto, Gonçalo Figueiredo %A Valeria Alfonsi %A Martina Del Manso %A Anna Rita Ciccaglione %A Mellou, Kassiani %A Christos Hadjichristodoulou %A Alastair Donachie %A Maria-Louise Borg %A Maja Sočan %A Poljak, Mario %A Ettore Severi %K ADOLESCENT %K Adult %K Aged %K Aged, 80 and over %K Child %K Child, Preschool %K Disease Outbreaks %K Europe %K European Union %K Genotype %K Hepatitis A %K hepatitis A virus %K Homosexuality, Male %K Hospitalization %K Humans %K Infant %K Infant, Newborn %K Male %K middle aged %K Risk Factors %K Sexual Behavior %K Spain %K Young adult %X

Between 1 June 2016 and 31 May 2017, 17 European Union (EU) and European Economic Area countries reported 4,096 cases associated with a multi-country hepatitis A (HA) outbreak. Molecular analysis identified three co-circulating hepatitis A virus (HAV) strains of genotype IA: VRD_521_2016, V16-25801 and RIVM-HAV16-090. We categorised cases as confirmed, probable or possible, according to the EU outbreak case definitions. Confirmed cases were infected with one of the three outbreak strains. We investigated case characteristics and strain-specific risk factors for transmission. A total of 1,400 (34%) cases were confirmed; VRD_521_2016 and RIVM-HAV16-090 accounted for 92% of these. Among confirmed cases with available epidemiological data, 92% (361/393) were unvaccinated, 43% (83/195) travelled to Spain during the incubation period and 84% (565/676) identified as men who have sex with men (MSM). Results depict an HA outbreak of multiple HAV strains, within a cross-European population, that was particularly driven by transmission between non-immune MSM engaging in high-risk sexual behaviour. The most effective preventive measure to curb this outbreak is HAV vaccination of MSM, supplemented by primary prevention campaigns that target the MSM population and promote protective sexual behaviour.

%B Euro Surveill %V 23 %8 2018 08 %G eng %N 33 %R 10.2807/1560-7917.ES.2018.23.33.1700641