title: Molecular epidemiology of a large outbreak of hepatitis B linked to autohaemotherapy.
abstract: BACKGROUND
  Unregulated skin-piercing procedures potentially facilitate the transmission of bloodborne pathogens. In February, 1998, a patient who had recently received autohaemotherapy at an alternative medicine clinic in the UK was diagnosed with acute hepatitis B. The autohaemotherapy procedure involved the drawing of 1 mL of the patient's blood, mixing with saline, and reinjection of the autologous blood mixture. We investigated the extent of hepatitis B virus (HBV) infection in patients and staff of the clinic.
  
  
  METHODS
  Patients who had attended the clinic between January, 1997, and February, 1998, were tested for serological markers of HBV, and for HBV DNA by PCR. HBV DNA was sequenced to assess the relatedness of the virus identified in the cases. We analysed the number and dates of visits with regard to HBV status.
  
  
  RESULTS
  Serum samples were received from 352 patients and four staff members. Serological evidence of exposure to HBV was found in 57 (16%). Of the 33 patients and staff who were positive for hepatitis B surface antigen, 30 (91%) showed complete nucleotide identity in the DNA segments derived from the surface and core genes. Five patients with linked infection had markers of chronic hepatitis B, and one of these was regarded as the likely source of the outbreak. The attack rate was associated with the number of visits (p<0.0001) and the week of visit (p=0.011). Contaminated saline in a repeatedly used bottle was the probable vehicle of transmission.
  
  
  CONCLUSIONS
  We have described a large community-based outbreak of hepatitis B due to transmission by a single HBV variant. Our findings emphasise the continuing risk of transmission of bloodborne viruses in all health-care settings where skin-piercing procedures are used.
authors.affiliation: Centre for Hepatology, Department of Medicine, Royal Free and University College Medical School, London, UK.
authors.forename: G J
authors.initials: GJ
authors.lastname: Webster
authors.forename: R
authors.initials: R
authors.lastname: Hallett
authors.forename: S A
authors.initials: SA
authors.lastname: Whalley
authors.forename: M
authors.initials: M
authors.lastname: Meltzer
authors.forename: K
authors.initials: K
authors.lastname: Balogun
authors.forename: D
authors.initials: D
authors.lastname: Brown
authors.forename: C P
authors.initials: CP
authors.lastname: Farrington
authors.forename: S
authors.initials: S
authors.lastname: Sharma
authors.forename: G
authors.initials: G
authors.lastname: Hamilton
authors.forename: S C
authors.initials: SC
authors.lastname: Farrow
authors.forename: M E
authors.initials: ME
authors.lastname: Ramsay
authors.forename: C G
authors.initials: CG
authors.lastname: Teo
authors.forename: G M
authors.initials: GM
authors.lastname: Dusheiko
mesh_terms: D000328:Adult; D017714:Community-Acquired Infections / Q000453:epidemiology*; D000529:Complementary Therapies / Q000379:methods*; D004279:DNA, Viral / Q000235:genetics; D005260:Female; D006509:Hepatitis B / Q000453:epidemiology* / Q000635:transmission / Q000821:virology; D006515:Hepatitis B virus / Q000235:genetics; D006801:Humans; D014182:Transplantation, Autologous / Q000379:methods*; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D004279:DNA, Viral