ORIGINAL ARTICLE 46 Le Infezioni in Medicina, n. 1, 46-51, 2018 Corresponding author Agnese Comelli E-mail: a.comelli@unibs.it n INTRODUCTION H epatitis A is an acute infection caused by hepatitis A virus (HAV). Spread is most commonly from person to person (including sexual contact), but it can be transmit- ted by faecal-oral route through contaminated food or water, among injection drug users and rarely by infected blood products. HAV infection is usually asymptomatic in chil- dren. In adults, after a silent incubation period of 15-50 days, onset is usually gradual with aspecif- ic, fulike symptoms like mild fever, abdominal discomfort, fatigue, anorexia. One to 7 days after jaundice onset, hyperchromic urines and acholic faeces can appear. Normally, HAV infection is self limiting, but rarely it can lead to fulminant hepa- titis and liver transplantation. Among several risk factors for poor outcome of hepatitis A the more common are: age >60 years, chronic liver disease, hepatitis B and/or C, HIV/AIDS, immunosup- pressive therapy. The maximum infectivity is during the second half of asymptomatic incubation period until frst week of jaundice. To confrm the diagnosis, increased ALT and positive anti-HAV IgM are needed. No specifc treatment exists. Prevention with in- activated vaccination, strict control measures, en- forced hygiene and contact tracing are therefore the only way to reduce the burden of HAV infec- tion [1]. Men who have sex with men (MSM) have greater risk to be infected and to transmit HAV because Hepatitis A outbreak in men who have sex with men (MSM) in Brescia (Northern Italy), July 2016-July 2017 Agnese Comelli, Ilaria Izzo, Salvatore Casari, Angiola Spinetti, Alberto Bergamasco, Francesco Castelli University Department of Infectious and Tropical Diseases, University of Brescia and Spedali Civili General Hospital, Brescia, Italy Since June 2016, an outbreak of hepatitis A has been reported in Europe. Here we report the HAV outbreak in Brescia (Northern Italy) from July 2016 to July 2017. We actively recorded all HAV cases defned by detec- tion of HAV IgM antibodies in serum. Data on sexual behaviour, travel attitudes, concomitant sexually trans- mitted diseases (STDs), clinical presentation and labora- tory results were collected. Forty-two confrmed cases were recorded: 25 (60%) were MSM and reported sexual contact at risk of STDs. Compared to 2015 and the frst half of 2016, when only three hepatitis A cases were re- corded, in the 12 months in question the number of cas- es rose 14-fold. Among 25 MSM, 14 were HIV-infected. SUMMARY Hepatitis A is usually a self-limiting disease, but it could be more serious in the case of HIV co-infection, immu- nosuppression and chronic hepatitis. HAV infection has a high outbreak potential in MSM because of more common oro-anal practices compared to HS, a high in- terconnectedness global network, chemsex practices and a new tendency to travel abroad to attend group sex events. In our experience, most cases occurred in MSM and 56% of them were HIV-infected, suggesting the need to promote active screening, immunization and education in this population. Keywords: hepatitis A, MSM, HIV infection