title: Serological survey on hepatitis E virus infection in an endemic area: diagnosis potential of enzyme immunoassay for detection of IgG antibody.
abstract: BACKGROUND
  Hepatitis E is a major cause of acute icteric disease widespread in tropical and sub-tropical regions but rarely occurring in industrialized countries. Recently solid-phase enzyme immunoassays with recombinant antigens have been introduced for diagnosis of this infection.
  
  
  OBJECTIVE
  The aim of this study was to evaluate the diagnostic potential of a newly developed Abbott test for the detection of IgG class antibodies to hepatitis E virus (anti-HEV IgG) in hepatitis patients and 'normal' individuals.
  
  
  METHODS
  Sera taken from hepatitis patients and individuals without liver disorders in endemic (Kirghizstan and Uzkbekistan) versus non-endemic (Moscow) areas were investigated. In parallel IgG class antibodies to hepatitis A virus (anti-HAV IgG) were determined by an enzyme immunoassay with native HAV antigen.
  
  
  RESULTS
  In five groups comprising altogether 86 suspected hepatitis E patients from endemic area the rate of anti-HEV IgG seropositivity varied from 85% to 17%. In Moscow anti-HEV IgG was found in one patient (who also had acute hepatitis B) out of 19. Anti-HEV IgG persisted in an experimentally infected volunteer for at least 12 years after the acute disease. Among the individuals without liver disorders eight out of 173 (4.6%) showed anti-HEV IgG seropositivity in Kirghizstan while there was only one seropositive out of 165 (0.6%) in Moscow. In contrast, anti-HAV IgG were frequently present in the residents of both areas: in Kirghizstan over 90% of individuals from young age groups already had these antibodies; in Moscow the rate of anti-HAV IgG seropositivity constantly increased from 31% in the youngest age group to almost 85% in the oldest one.
  
  
  CONCLUSIONS
  Prevalence of anti-HEV antibodies was unexpectedly low in endemic area; in Moscow anti-HEV IgG was found only in single cases. Anti-HEV IgG seropositivity in a single serum sample could be of certain diagnostic value in non-endemic areas.
authors.affiliation: Institute of Poliomyelitis and Viral Encephalitides, Moscow, Russia.
authors.forename: M S
authors.initials: MS
authors.lastname: Balayan
authors.forename: N A
authors.initials: NA
authors.lastname: Zamyatina
authors.forename: M I
authors.initials: MI
authors.lastname: Mikhailov
authors.forename: A V
authors.initials: AV
authors.lastname: Sychev
authors.forename: R K
authors.initials: RK
authors.lastname: Usmanov
authors.forename: O V
authors.initials: OV
authors.lastname: Dvoynikova
authors.forename: I V
authors.initials: IV
authors.lastname: Nelga
authors.forename: G K
authors.initials: GK
authors.lastname: Grishina
authors.forename: L A
authors.initials: LA
authors.lastname: Ankhundinova