title: Hepatitis C virus infection among institutionalised psychiatric patients: a regression analysis of indicators of risk.
abstract: OBJECTIVE
  Institutionalised psychiatric patients are at increased risk of developing chronic infection with hepatitis B virus (HBV). However, little information is available on transmission and epidemiology of hepatitis C virus (HCV) in this setting. The aim of this study was to identify potential risk factors of acquiring HCV infection in two large psychiatric institutions in northern Italy.
  
  
  METHODS
  We designed a case-control study using randomly selected controls from the same study database, consisting of a total of 1180 patients, in order to satisfy the principle that both cases and controls should be representative of the same base experience. A multiple regression logistic analysis was used to identify features that could predict exposure to HCV as evidenced by the presence of circulating anti-HCV antibodies.
  
  
  RESULTS
  Anti-HCV was detected in 79 patients (6.7%). The prevalence of viraemia and the distribution of genotypes were very similar to those found in subjects with chronic HCV infection drawn from the same geographical area. Multivariate analysis indicated that a diagnosis of psychosis and a history of trauma were statistically significant independent risk factors associated with a positive anti-HCV result (OR 2.615, 1.273-5.373 95% CI and OR 2.096, 1.133-3.877 95% CI, respectively).
  
  
  CONCLUSIONS
  The findings of this large epidemiological study show for the first time that prolonged residence in psychiatric institutions does not entail per se a significant risk of acquiring HCV infection. Since transmission of HCV in this setting appears to occur predominantly via classical parenteral routes, simple prophylactic measures appear to be adequate to prevent infection.
authors.affiliation: Istituto di Clinica delle Malattie Infettive, University of Pavia, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Cividini
authors.forename: A
authors.initials: A
authors.lastname: Pistorio
authors.forename: A
authors.initials: A
authors.lastname: Regazzetti
authors.forename: A
authors.initials: A
authors.lastname: Cerino
authors.forename: C
authors.initials: C
authors.lastname: Tinelli
authors.forename: A
authors.initials: A
authors.lastname: Mancuso
authors.forename: M
authors.initials: M
authors.lastname: Ribola
authors.forename: M L
authors.initials: ML
authors.lastname: Galli
authors.forename: A
authors.initials: A
authors.lastname: Agnusdei
authors.forename: M
authors.initials: M
authors.lastname: Leone
authors.forename: E
authors.initials: E
authors.lastname: Silini
authors.forename: M U
authors.initials: MU
authors.lastname: Mondelli
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D006526:Hepatitis C / Q000453:epidemiology / Q000635:transmission*; D006778:Hospitals, Psychiatric; D006801:Humans; D007326:Institutionalization; D007558:Italy / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012044:Regression Analysis; D012307:Risk Factors