title: Hepatic and extra-hepatic sequelae, and prevalence of viral hepatitis C infection estimated from routine data in at-risk groups.
abstract: BACKGROUND
  Concerns about the hepatitis C virus (HCV) are due to the high risk of chronic liver disease and poor treatment efficacy. Synthesizing evidence from multiple data sources is becoming widely used to estimate HCV-infection prevalence. This paper aims to estimate the prevalence of HCV infection, and the hepatic and extrahepatic sequelae in at-risk groups, using routinely collected data in the Lazio region, Italy.
  
  
  METHODS
  HCV laboratory surveillance and dialysis, hospital discharge, and drug-user registers were used as information sources to identify at-risk groups and to estimate HCV prevalence and sequelae.Full name and birth date were used as linkage keys for the various health registries. Prevalence was estimated as the percentage of cases within the general population and the at-risk groups, with 95% confidence intervals (95% CI) from 1997 to 2001. The risk of sequelae was estimated through a follow-up of hospital discharges up to December 31, 2004 and calculated as the prevalence ratio in HCV-positive and HCV-negative people, within each at-risk group, with 95% CI.
  
  
  RESULTS
  There were 65,127 HCV-infected people in the study period; the prevalence was 1.24% (95%CI = 1.23%-1.25%) in the whole population, higher in males and older adults. Drug users (35.1%; 95%CI = 34.6-35.7) and dialysis patients (21.1%; 95%CI = 20.2%-22.0%) showed the highest values. Medical procedures with little exposure to blood resulted in higher estimates, ranging between 1.3% and 3.4%, which was not conclusively attributable to the surgical procedures. Cirrhosis, hepatocellular carcinoma and encephalopathy were the most frequent hepatic sequelae; cryoglobulinaemia and non-Hodgkin's lymphoma were the most frequent extrahepatic sequelae.
  
  
  CONCLUSIONS
  Synthesising data from multiple routine sources improved estimates of HCV prevalence and sequelae in dialysis patients and drug users, although prevalence validity should be assessed in survey and sequelae need a well-defined longitudinal approach.
authors.affiliation: Department of Epidemiology, Regional Health System - Lazio Region, Via S, Costanza 53, 00198, Rome, Italy. faustini@asplazio.it
authors.forename: Annunziata
authors.initials: A
authors.lastname: Faustini
authors.forename: Paola
authors.initials: P
authors.lastname: Colais
authors.forename: Emanuele
authors.initials: E
authors.lastname: Fabrizi
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Bargagli
authors.forename: Marina
authors.initials: M
authors.lastname: Davoli
authors.forename: Domenico
authors.initials: D
authors.lastname: Di Lallo
authors.forename: Anteo
authors.initials: A
authors.lastname: Di Napoli
authors.forename: Patrizio
authors.initials: P
authors.lastname: Pezzotti
authors.forename: Chiara
authors.initials: C
authors.lastname: Sorge
authors.forename: Rita
authors.initials: R
authors.lastname: Grillo
authors.forename: Carla
authors.initials: C
authors.lastname: Maresca
authors.forename: Olga
authors.initials: O
authors.lastname: Recchia
authors.forename: Carlo A
authors.initials: CA
authors.lastname: Perucci
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006526:Hepatitis C / Q000150:complications* / Q000453:epidemiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007558:Italy / Q000453:epidemiology; D008103:Liver Cirrhosis / Q000453:epidemiology; D008113:Liver Neoplasms / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D020258:Neurotoxicity Syndromes / Q000453:epidemiology; D015995:Prevalence; D006435:Renal Dialysis / Q000009:adverse effects; D012737:Sex Factors; D019966:Substance-Related Disorders / Q000150:complications; D055815:Young Adult
references.citation: J Viral Hepat. 2008 Jul;15(7):538-50
references.pmid: 18397223
references.citation: Lancet. 1998 Jan 31;351(9099):351-5
references.pmid: 9652633
references.citation: J Clin Virol. 2009 Mar;44(3):200-6
references.pmid: 19195927
references.citation: Gut. 1999 Jun;44(6):874-80
references.pmid: 10323892
references.citation: Am J Kidney Dis. 2001 May;37(5):1004-10
references.pmid: 11325683
references.citation: Rev Soc Bras Med Trop. 2009 May-Jun;42(3):239-44
references.pmid: 19684968
references.citation: Int J Epidemiol. 2007 Aug;36(4):731-7
references.pmid: 17693458
references.citation: JAMA. 1996 Nov 20;276(19):1563-7
references.pmid: 8918853
references.citation: Am J Gastroenterol. 2001 Nov;96(11):3138-41
references.pmid: 11721761
references.citation: Blood. 2004 Mar 1;103(5):1618-24
references.pmid: 14576071
references.citation: Blood. 2003 Aug 1;102(3):996-9
references.pmid: 12714514
references.citation: J Hepatol. 2001 Aug;35(2):284-9
references.pmid: 11580153
references.citation: Am J Kidney Dis. 2006 Oct;48(4):629-37
references.pmid: 16997059
references.citation: Minerva Urol Nefrol. 2005 Sep;57(3):175-97
references.pmid: 15986016
references.citation: N Engl J Med. 2001 Jul 5;345(1):41-52
references.pmid: 11439948
references.citation: J Med Virol. 2005 Dec;77(4):509-18
references.pmid: 16254983
references.citation: NIH Consens State Sci Statements. 2002 Jun 10-12;19(3):1-46
references.pmid: 14768714
references.citation: N Engl J Med. 1997 Jul 24;337(4):237-40
references.pmid: 9227929
references.citation: J Hepatol. 2008 Jan;48(1):148-62
references.pmid: 18022726
references.citation: Cent Eur J Public Health. 2008 Sep;16(3):106-10
references.pmid: 18935772
references.citation: Clin Nephrol. 2009 Apr;71(4):423-9
references.pmid: 19356375
references.citation: BMC Public Health. 2009 Jan 22;9:34
references.pmid: 19161623
references.citation: J Med Virol. 2009 May;81(5):836-43
references.pmid: 19319981
references.citation: Blood. 2002 Jun 15;99(12):4588-91
references.pmid: 12036892
references.citation: Lancet. 2003 Dec 20;362(9401):2095-100
references.pmid: 14697814
references.citation: BMJ. 1998 Aug 15;317(7156):433-7
references.pmid: 9703523
references.citation: Infect Control Hosp Epidemiol. 2005 Sep;26(9):762-7
references.pmid: 16209382
references.citation: World J Gastroenterol. 2009 Apr 7;15(13):1537-47
references.pmid: 19340895
references.citation: Ann Intern Med. 2006 May 16;144(10):705-14
references.pmid: 16702586
references.citation: BMJ. 2002 Feb 23;324(7335):450-3
references.pmid: 11859045
references.citation: J Pediatr. 2003 Jul;143(1):54-9
references.pmid: 12915824
references.citation: Lancet Infect Dis. 2005 Sep;5(9):558-67
references.pmid: 16122679
references.citation: Biostatistics. 2008 Oct;9(4):715-34
references.pmid: 18349037
references.citation: J Rheumatol. 1999 Feb;26(2):370-2
references.pmid: 9972971
references.citation: World J Gastroenterol. 2007 May 7;13(17):2436-41
references.pmid: 17552026
references.citation: Int J Epidemiol. 2003 Oct;32(5):717-24
references.pmid: 14559738
references.citation: World J Gastroenterol. 2007 May 7;13(17):2467-78
references.pmid: 17552031
references.citation: N Engl J Med. 1999 Aug 19;341(8):556-62
references.pmid: 10451460