title: An outbreak of hepatitis A in young adults in central Italy.
abstract: Between September, 1988 and January, 1989 a common source outbreak of 47 cases of serologically confirmed hepatitis A occurred in a town of central Italy. Thirty-eight cases were primary, three co-primary and six secondary. The highest age-specific attack rate was seen in subjects aged 15-24 years (120 per 100,000); the mean age of cases was 24.6 years and the median age was 22 years. A matched triplet case-control study showed significant association between the disease and consumption of either raw mussels (41% of cases, compared with 10% of controls; P less than 0.0001) or a single brand of mineral water (63% of cases, compared with 41% of controls; P less than 0.05). The mean age of the cases reflects the shift in primary susceptibility to the infection from younger to older age groups, a finding which has recently been demonstrated by several seroepidemiological surveys in Italy.
authors.affiliation: Laboratorio di Epidemiologia, Istituto Superiore di Sanità, Roma, Italy.
authors.forename: T
authors.initials: T
authors.lastname: Stroffolini
authors.forename: W
authors.initials: W
authors.lastname: Biagini
authors.forename: L
authors.initials: L
authors.lastname: Lorenzoni
authors.forename: G P
authors.initials: GP
authors.lastname: Palazzesi
authors.forename: M
authors.initials: M
authors.lastname: Divizia
authors.forename: R
authors.initials: R
authors.lastname: Frongillo
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D049872:Bivalvia / Q000382:microbiology; D016022:Case-Control Studies; D004196:Disease Outbreaks / Q000706:statistics & numerical data*; D005260:Female; D005516:Food Microbiology; D006506:Hepatitis A / Q000453:epidemiology* / Q000635:transmission; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D012307:Risk Factors; D014871:Water Microbiology