RT Journal Article SR Electronic(1) A1 Scavia, Gaia A1 Alfonsi, Valeria A1 Taffon, Stefania A1 Escher, Martina A1 Bruni, Roberto A1 Medici, Dario De A1 Pasquale, Simona Di A1 Guizzardi, Sarah A1 Cappelletti, Benedetta A1 Iannazzo, Stefania A1 Losio, Nadia Marina A1 Pavoni, Enrico A1 Decastelli, Lucia A1 Ciccaglione, Anna Rita A1 Equestre, Michele A1 Tosti, Maria Elena A1 Rizzo, Caterina A1 National Italian Task Force on Hepatitis AYR 2017 T1 A large prolonged outbreak of hepatitis A associated with consumption of frozen berries, Italy, 2013–14 JF Journal of Medical Microbiology, VO 66 IS 3 SP 342 OP 349 DO https://doi.org/10.1099/jmm.0.000433 PB Microbiology Society, SN 1473-5644, AB Purpose. In 2013/2014, Italy experienced one of the largest community-wide prolonged outbreaks of hepatitis A virus (HAV) throughout the country. The article provides a comprehensive description of the outbreak and the investigation carried out by a multidisciplinary National Task Force, in collaboration with regional and local public health authorities. Control strategies of food-borne HAV infection in both the human and food sectors are also described. Methodology. Enhanced human epidemiological and microbiological surveillance together with microbiological monitoring of HAV in food and trace-back investigation were conducted. Results. A total of 1803 HAV cases were identified from 1 January 2013 to 31 August 2014, in Italy. Sequencing was possible for 368 cases (20.4 %), mostly collected between 1 January 2013 and 28 February 2014, and 246 cases (66.8 %) harboured an HAV outbreak strain. Imported frozen berries contaminated with HAV were identified as the vehicle of the outbreak which also involved many other European countries in 2013 and 2014. Epidemiological evidence obtained through a case–control study was supported by the finding of a 100 % nucleotide similarity of the VP1/2A sequences of HAVs detected in human and food samples. Trace-back investigation revealed an extremely complex supplying network with no possibility for a point source potentially explaining the vast contamination of berries found in Italy. Conclusion. The investigation benefited from an excellent collaboration among different sectors who shared proactively the available information. Our findings highlight the importance of considering frozen berries among the highest risk factors for HAV., UL https://www.microbiologyresearch.org/content/journal/jmm/10.1099/jmm.0.000433