title: [Serological characteristics of a hepatitis E outbreak].
abstract: OBJECTIVE
  To look into the serological characteristics of a hepatitis E outbreak.
  
  
  METHODS
  Sera from the first five patients with acute icteric hepatitis who developed the disease successively within ten days and the 1,675 employees routinely having their lunch in a dining hall of a department (outbreak population) were examined for anti.HEV IgM and IgG at 26th days after the outbreak, and the 883 employees of a neighboring department not having their lunch in the hall were selected as control (control population).
  
  
  RESULTS
  The five patients were all positive for anti-HEV IgM and IgG. The positive rates of anti-HEV IgM and IgG in outbreak population were 8.7% and 38.4% respectively, both significantly higher than those in control population which were only 0.1% and 28.6%. The numbers with abnormal ALT in the 145 individuals with anti-HEV IgM(+) of outbreak population were significantly higher than those in the IgM(-) individuals of the same group as well as in control, while the abnormal ALT ratio in the IgM(-) individuals of the outbreak was not higher than that in control. The results from the four patients' serial sera showed that the anti-HEV IgM titers declined gradually and were undetectable at about 4th month after infection, and the IgG titers increased to peak in about 2-3 months after infection, then declined very slowly. The mean IgG titer of the anti-HEV IgM(+) individuals was significantly higher than that of the IgM(-) but IgG(+) individuals in outbreak population, and the latter was significantly higher than the IgG(+) individuals in control, which suggested that the post-infection individuals' immunities to HEV were boosted during the outbreak. There was no difference between sex or age groups for the anti-HEV IgM(+) ratio, but the abnormal ALT was much more frequent in the anti-HEV IgM(+) male than in the female, and no difference was observed between age groups.
  
  
  CONCLUSIONS
  The pathogen of the outbreak of acute icteric hepatitis was hepatitis E virus and associated with food intake. Anti-HEV IgM and IgG were used not only for diagnosis of hepatitis E but also for surveilance in mass population. The attack risk was not associated with age or sex, but the abnormal ALT was much more frequent fresh infectors in male.
authors.affiliation: Department of Clinical Laboratory, Beijing Railway General Hospital, Beijing 100038, China. crtan@vip.sina.com.
authors.forename: Chun-rong
authors.initials: CR
authors.lastname: Tan
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.forename: Sheng-xiang
authors.initials: SX
authors.lastname: Ge
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.forename: Mei
authors.initials: M
authors.lastname: Hu
authors.forename: Huan-ying
authors.initials: HY
authors.lastname: Sun
authors.forename: Yan
authors.initials: Y
authors.lastname: Chen
authors.forename: Geng
authors.initials: G
authors.lastname: Peng
authors.forename: Wei
authors.initials: W
authors.lastname: Shen
authors.forename: Man
authors.initials: M
authors.lastname: Zhang
authors.forename: Ning-shao
authors.initials: NS
authors.lastname: Xia
mesh_terms: D000328:Adult; D004196:Disease Outbreaks; D005260:Female; D006508:Hepatitis Antibodies / Q000097:blood; D016751:Hepatitis E / Q000453:epidemiology*; D016752:Hepatitis E virus / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D008875:Middle Aged; D016036:Seroepidemiologic Studies
chemical_list: D006508:Hepatitis Antibodies; D007074:Immunoglobulin G; D007075:Immunoglobulin M