title: An outbreak of hepatitis A in recently vaccinated students from ice snacks made from contaminated well water.
abstract: On 30 May 2006, township S in Sichuan Province, China, reported an outbreak of hepatitis A (HA) in students who had recently received HA vaccine. The concern was raised that the vaccine had caused the outbreak. We attempted to identify the source of infection and mode of transmission. A HA case was defined as onset of jaundice or anorexia since 1 April 2006 with a twofold elevation of alanine aminotransferase (ALT) and anti-HA virus-IgM in a resident of or visitor to the township. Exposures to vaccine and snacks of 90 case-students to those of 107 control-students were compared. Thirty-four per cent of cases ate ice slush compared to 4.7% of controls (OR 4.1), and 51% of cases ate snow cones compared to 17% of controls (OR 8.3). The ice snacks were made with well water. HA virus RNA was detected by reverse transcription-polymerase chain reaction from patients' blood and well water. Untreated well water poses important dangers to the public in areas where piped, potable water is available.
authors.affiliation: Chinese Field Epidemiology Training Programme (CFETP), Chinese Centre for Disease Control and Prevention, China.
authors.forename: L J
authors.initials: LJ
authors.lastname: Zhang
authors.forename: X J
authors.initials: XJ
authors.lastname: Wang
authors.forename: J M
authors.initials: JM
authors.lastname: Bai
authors.forename: G
authors.initials: G
authors.lastname: Fang
authors.forename: L G
authors.initials: LG
authors.lastname: Liu
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: R E
authors.initials: RE
authors.lastname: Fontaine
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D004196:Disease Outbreaks; D005260:Female; D006506:Hepatitis A / Q000453:epidemiology* / Q000517:prevention & control; D022362:Hepatitis A Vaccines; D006801:Humans; D007053:Ice; D008297:Male; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014871:Water Microbiology
chemical_list: D022362:Hepatitis A Vaccines; D007053:Ice