Nosocomial hepatitis C in a thoracic surgery unit; retrospective findings generating a prospective study.

We describe the transmission of hepatitis C virus (HCV) to two patients from a thoracic surgeon who was unaware of his hepatitis C infection. By partial sequencing of the non-structural 5B gene and phylogenetic analysis, the viruses from both patients were found to be closely related to genotype 1a strain from the surgeon. Two further hepatitis C cases were found in relation to the thoracic clinic. Their HCV sequences were related to each other but were of genotype 2b and the source of infection was never revealed. To elucidate the magnitude of the problem, we conducted a prospective study for a period of 17 months in which patients who were about to undergo thoracic surgery were asked to participate. Blood samples were drawn prior to surgery and at least four months later. The postoperative samples were then screened for anti-HCV and, if positive, the initial sample was also analysed. The only two patients (0.4%) identified were confirmed anti-HCV positive before surgery, and none out of 456 evaluable cases seroconverted to anti-HCV during the observation period. Despite the retrospectively identified cases, nosocomial hepatitis C is rare in our thoracic unit. The study points out the risk of transmission of hepatitis C from infected personnel and reiterates the need for universal precautions.

Detection and prevention of hepatitis C in dialysis patients and renal transplant recipients. A long-term follow up (1989-January 1997).

BACKGROUND: Hepatitis C is frequent problem in dialysis wards. DESIGN: A long time (1989-97) follow up of hepatitis C virus (HCV) infection in a Swedish nephrology unit was performed with anti-HCV screening, confirmatory antibody tests, viral RNA detection and molecular characterization. Case histories were reviewed with focus, onset of infection, liver morbidity and mortality. RESULTS: In October 1991, 10% (19 of 184) of the patients in the unit (haemodialysis-, peritoneal dialysis and transplanted patients) were verified or suspected HCV carriers, whilst the number at the end of 1996 was 8%, (13 of 157). Most patients were infected before 1991 but only in one case from a known HCV-infected blood donor. No new HCV infections associated with haemodialysis occurred during the study period. A total of 13 of 24 viremic patients had HCV genotype 2b, a pattern suggesting nosocomial transmission. This was further supported by phylogenetic analysis of HCV viral isolates in seven. HCV viremia was also common in patients with an incomplete anti-HCV antibody pattern as 8 of the 12 indeterminant sera were HCV-RNA positive. CONCLUSIONS: Awareness, prevention, identification of infected patients and donor testing limited transmission. Indeterminant recombinant immunoblot assays (RIBA)-results should be regarded with caution as a result of the relative immunodeficiency in uremic patients. Our data indicate nosocomial transmission in several patients.

Continued transmission of hepatitis B and C viruses, but no transmission of human immunodeficiency virus among intravenous drug users participating in a syringe/needle exchange program.

The virological efficacy of a syringe/needle exchange program was evaluated in a cohort incidence study. Of 698 intravenous drug users (IVDUs) initially recruited, 15 (2.1%) were HIV-positive at baseline. Adequate follow-up was possible in 515 (74%) and showed no new cases of HIV infection during a median of 31 months. Most IVDUs had been previously exposed to HBV (anti-HBc-positive 70.1%) and HCV (anti-HCV-positive 90.7%). Of those 159 IVDUs negative at baseline for anti-HBc and/or anti-HCV, 56 (35%) seroconverted to one or both viruses during follow-up, corresponding to 11.7 seroconversions/100 y at risk for HBV and 26.3 seroconversions/100 y for HCV. Multiple logistic regression analysis showed hepatitis seroconversion to correlate with imprisonment during the study (OR 2.2; 95% CI 1.04-4.74), absence of drug-free periods (OR 5.7; CI 1.44-22.3) and frequent syringe/needle exchanges (OR 1.31; CI 1.02-1.7). The absence of HIV spread was probably partly due to the low prevalence of HIV-infected IVDUs in the city. Despite free syringes and needles, both HBV and HCV continued to spread at high rates. Nevertheless, syringe/needle exchange programs, coupled with monitoring of serostatus provide good surveillance and are valuable for further assessment of remaining risks.

The impact of hepatitis C antibody screening of source plasma donors on hepatitis C virus RNA in factor VIII concentrates.

We have used the polymerase chain reaction technique for the detection of hepatitis C RNA in nine different plasma-derived factor VllI concentrates and in two factor IX concentrates. Four concentrates were investigated both prior to and after the introduction of donor screening for hepatitis C antibodies. A negative reaction was consistently found in the ultra-pure factor VIII concentrates Octonativ-M (Pharmacia) and Hemofil M (Baxter), both prepared by affinity purification with factor VI1I:C monoclonal antibodies and virus inacti- vated hy solvent/detergent procedures, as well as in both the low-purity factor IX concentrates. I f produced from unscreened plasma, the other factor VIII concentrates manifested positive reactions irrespective of preparation procedure and type of virus inactivation or the temperature at which it was performed. We conclude that the preparation procedure of clotting factor concentrates, rather than type of virus inactivation, determines the degree of contamination by hepatitis C virus RNA, and that screening of source plasma seems effective in removing hepatitis C RNA from the final product as determined with a sensitive PCR method. I t is important to stress that the presence of viral RNA does not necessarily imply clinical infectivity.

Second-generation hepatitis C Elisa antibody tests confirmed by the four-antigen recombinant immunoblot assay correlate well with hepatitis C viremia and chronic liver disease in Swedish blood donors.

Seventy-three Swedish blood donors (52 men, 21 women; median age 36 years) repeatedly reactive for hepatitis C antibodies (anti-HCV C-100-3) were tested with a second-generation (2nd-gen) anti-HCV Elisa and a 4-band recombinant immunoblot assay (RIBA 2). These results were correlated to serum alanine aminotransferase (S-ALAT), liver morphology and viremia as detected by 'nested' polymerase chain reaction (PCR) based on primers from a 5'-noncoding sequence of the HCV genome. Thirty-five of 46 (76%) donors with positive 2nd-gen Elisa tests confirmed by RIBA 2 were PCR positive whereof 27 had histological findings compatible with chronic persistent hepatitis (CPH) and 7 had chronic active hepatitis (CAH). Ten of 56 (18%) 2nd-gen Elisa-positive donors were RIBA 2 negative (or indeterminate) and none of these had chronic hepatitis nor were PCR positive. Seventeen of 73 (23%) donors were 1st-gen Elisa positive but 2nd-gen Elisa negative. All of these were PCR negative and only 1 (6%) had chronic hepatitis (CPH). An elevated S-ALAT level (reference < 0.7 mu kat/l) was found in 26 2nd-gen Elisa and RIBA 2-positive donors of which 18 had CPH and 7 had CAH and all 25 were PCR positive. A normal S-ALAT level was found in 9 of 34 (26%) donors with chronic hepatitis (all had CPH) and positive PCR. We have found that blood donors with positive 2nd-gen anti-HCV Elisa tests confirmed by RIBA-2 and especially with a concomitant elevated S-ALAT are highly likely to be viremic as demonstrated by PCR and to have chronic hepatitis.

Mother-to-infant transmission of hepatitis C virus.

OBJECTIVE: To describe the rate of perinatal transmission of hepatitis C virus (HCV). DESIGN: Follow-up study of newborn children of mothers with chronic HCV infection. SETTING: A university hospital in Sweden. PARTICIPANTS: Fourteen women with chronic HCV infection and their 21 newly born children. MAIN OUTCOME MEASURES: Detection of HCV RNA in serum by the polymerase chain reaction and detection of anti-HCV antibody by second generation assays. RESULTS: All mothers were found to be positive for anti-HCV antibody both by second-generation enzyme-linked immunosorbent assay (ELISA) and by second-generation recombinant immunoblot assay (RIBA-2); all also had detectable serum HCV RNA. Two children had long-lasting alanine aminotransferase (ALT) elevations, and one of them became HCV RNA positive. None of the other children developed biochemical hepatitis. However, two additional children had temporary viremia. Only the child with biochemical and biopsy-proven hepatitis and detectable HCV RNA in multiple blood samples actively produced anti-HCV antibody. CONCLUSIONS: Mother-to-infant transmission of HCV infection from chronically infected women without human immunodeficiency virus (HIV) infection seems to be uncommon.

Hepatitis C virus RNA in blood donor sera detected by the polymerase chain reaction: comparison with supplementary hepatitis C antibody assays.

The low specificity of screening ELISAs for antibodies to hepatitis C virus in blood donors has called for confirmatory tests. Two types of supplementary antibody assays are available, recombinant immunoblot assays (RIBA-1 and RIBA-2) and an antibody consumption test referred to as a neutralization assay. Amplification of viral nucleic acid by the polymerase chain reaction (PCR) provides an antibody independent mode of detecting viral infection. We applied reverse transcription-double PCR to detect an HCV 5'-noncoding viral RNA sequence in serum specimens and compared PCR findings with confirmatory antibody tests. This study includes sera from 37 blood donors found positive by the Ortho anti-HCV (C100-3) ELISA out of 14,591 donations. Of the 37 positive sera, 8 were positive by RIBA-1 and 1 further by RIBA-2. Seven of the RIBA positive sera contained HCV RNA by PCR. Among the 8 indeterminate and the 21 negative donor sera by RIBA-1, no PCR positive serum was found. The 37 anti-HCV positive donor sera identified by Ortho ELISA were also tested by Abbott anti-HCV (C100-3) ELISA whereby 22 were positive. Of these 22 sera plus 1 further with ELISA OD just below cutoff, 8 were positive by the "neutralization assay," (Abbott Laboratories, North Chicago, IL, USA) and 6 of these, including the borderline serum, were PCR positive. One of the two neutralizable but PCR negative sera was RIBA positive and the other was indeterminate. However, one ELISA (Abbott Laboratories) positive (OD 1.99) serum was not neutralizable but nevertheless contained HCV RNA by PCR.(ABSTRACT TRUNCATED AT 250 WORDS)