title: Laboratory diagnosis of viral hepatitis C: The Sultan Qaboos University Hospital experience.
abstract: OBJECTIVE
  A retrospective study was carried out to assess the performance of hepatitis C diagnostic assays in our laboratory, and to determine the prevalence of hepatitis C among blood donors at the Sultan Qaboos University Hospital.
  
  
  METHODS
  From 1991 to 2001, approximately 55,000 serum samples collected from blood donors and patients were submitted to our laboratory for testing. All sera were screened for antibodies to hepatitis C virus (HCV) by three successive generations of the enzyme-linked immunosorbent assay (ELISA). Anti-HCV positive sera were further tested by recombinant immunoblot assay (RIBA). Reverse-transcriptase polymerase chain reaction (RT-PCR) for HCV RNA was carried out on a limited number (241) of ELISA positive samples.
  
  
  RESULTS
  Out of 30012 samples from blood donors that were screened for anti-HCV, 272 (0.91%) were positive. Of these, 46.5% were confirmed positive by RIBA. The proportion of patient sera that were confirmed positive varied from 95% among intravenous drug users to 81% in patients with hepatitis to 70% in those with haemoglobinopathies. HCV RNA was detected in 67%, 6%, and 0% of the RIBA positive, indeterminate and negative samples respectively.
  
  
  CONCLUSIONS
  Based on RIBA, the prevalence of anti-HCV among blood donors in Oman is close to 0.5%. In our experience, RIBA-positivity is predictive of HCV infection in two thirds of subjects, and HCV infection is highly unlikely in those who are RIBA-negative. The experience at SQUH with three types of HCV assays has enabled the laboratory to develop a test algorithm, starting with screening anti-HCV ELISA.
authors.affiliation: Department of Microbiology and Immunology, College of Medicine and Health Sciences, Sultan Qaboos University, P O Box 35, Al Khod, Muscat-123, Sultanate of Oman.
authors.forename: Said H S
authors.initials: SH
authors.lastname: Al Dhahry
authors.forename: Jameel C
authors.initials: JC
authors.lastname: Nograles
authors.forename: Situsekara M W W B
authors.initials: SM
authors.lastname: Rajapakse
authors.forename: Fadhila S S
authors.initials: FS
authors.lastname: Al Toqi
authors.forename: Geraldine Z
authors.initials: GZ
authors.lastname: Kaminski
keywords: ELISA; RIBA; hepatitis C virus; polymerase chain reaction
references.citation: Transfusion. 1995 Sep;35(9):745-9
references.pmid: 7570934
references.citation: J Med Virol. 1993 Nov;41(3):215-20
references.pmid: 7505306
references.citation: Wkly Epidemiol Rec. 1999 Dec 10;74(49):425-7
references.pmid: 10645164
references.citation: Scand J Gastroenterol. 1994 Jan;29(1):77-81
references.pmid: 8128181
references.citation: Semin Liver Dis. 1999;19 Suppl 1:3-15
references.pmid: 10349688
references.citation: Am J Kidney Dis. 1996 Sep;28(3):437-40
references.pmid: 8804244
references.citation: Hepatology. 1993 Feb;17(2):179-82
references.pmid: 8381380
references.citation: Ann Trop Med Parasitol. 1995 Aug;89(4):431-7
references.pmid: 7487230
references.citation: Semin Liver Dis. 2000;20(1):17-35
references.pmid: 10895429
references.citation: J Med Virol. 2001 Jul;64(3):320-4
references.pmid: 11424121
references.citation: Science. 1989 Apr 21;244(4902):359-62
references.pmid: 2523562
references.citation: Semin Liver Dis. 2000;20(1):1-16
references.pmid: 10895428
references.citation: Hepatology. 1997 Sep;26(3 Suppl 1):48S-56S
references.pmid: 9305664
references.citation: Transfusion. 2002 Nov;42(11):1507-13
references.pmid: 12421226
references.citation: J Med Virol. 1993 Aug;40(4):330-3
references.pmid: 8228926
references.citation: Semin Liver Dis. 1995 Feb;15(1):33-40
references.pmid: 7541160
references.citation: Vox Sang. 1994;66(2):122-9
references.pmid: 7514324
references.citation: Transfusion. 1993 Aug;33(8):634-8
references.pmid: 7688158
references.citation: J Clin Microbiol. 2001 Apr;39(4):1665-8
references.pmid: 11283113