| 1. |
- Widell, Anders, et al.
(författare)
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Genotyping of hepatitis C virus isolates by a modified polymerase chain reaction assay using type specific primers: epidemiological applications
- 1994
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Ingår i: Journal of Medical Virology. - : Wiley. - 1096-9071 .- 0146-6615. ; 44:3, s. 272-279
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Tidskriftsartikel (refereegranskat)abstract
- A polymerase chain reaction (PCR)-based assay using primers against the hepatitis C core gene has been described [Okamoto et al. (1992a): Journal of General Virology 73:673-679]. Within the two major HCV genotypes 1 and 2, the Okamoto system identifies two subtypes each (1a, 1b and 2a, 2b, respectively). Typing is achieved by a primary PCR with consensus primers followed by a nested PCR with type specific primers. The original assay was modified by addition of a parallel second PCR identifying the recently described major genotype 3. The assay also identifies in duplicate subtype 1b (type II by Okamoto), suggested to respond poorly to interferon. Reaction conditions were reviewed and melting temperatures of all typing primers equalised to increase strigency. The modified system functioned well and typing results were supported by partial core sequencing. The following distribution of genotypes was found in 53 hepatitis C virus (HCV) infected Swedish blood donors: genotype 1a (57%), 3 (19%), 1b (13%), and 2b (11%). In six recipients of HCV infected blood identified in a retrospective study, the recipient HCV genotype was identical to donor HCV genotype. Furthermore, in HCV positive couples identical genotype was observed when only one partner had an external risk factor; whereas genotypes were often diverse if both sex partners had parenteral risk factors. Finally, a cluster of hepatitis C cases in a haemodialysis unit was evaluated retrospectively. Eight patients had genotype 1b, two had mixed 1a and 1b, and one had type 1a. The modified HCV genotyping assay was of value in examining different epidemiological situations and can be expanded presumably to include future genotypes.
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| 2. |
- Zhang, Yong-Yuan, et al.
(författare)
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Antibodies to hepatitis C virus and hepatitis C virus RNA in Chinese blood donors determined by ELISA, recombinant immunoblot assay and polymerase chain reaction
- 1993
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Ingår i: Chinese Medical Journal. - 0366-6999. ; 106:3, s. 171-174
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Tidskriftsartikel (refereegranskat)abstract
- Antibodies to hepatitis C virus (anti-HCV) were determined in Chinese blood donors from the city of Wuhan by ELISA screening tests and confirmatory recombinant immunoblot assay (RIBA). 281 and 222 sera were sampled under similar conditions in 1989 and 1990, respectively. The first collection of sera was sent to Sweden in lyophilized form, the second directly as fresh, unfrozen sera. A high proportion (22%) of the lyophilized sera were positive in the screening assay but only 6 (2.10%) were positive by RIBA with antibodies against both the C100-3 and 5-1-1 peptides. HCV RNA could be detected by polymerase chain reaction (PCR) analysis in 3 of the 6 sera and in one reacting with C100-3 only. In the second material of fresh sera only 3 were positive in the screening anti-HCV ELISA, but none was RIBA or PCR positive. Thus, the overall prevalence of anti-HCV among the 503 Chinese blood donors as identified by RIBA was 1.2%, and that of HCV RNA by PCR was 0.8%. The confirmed antibody prevalence is higher than that reported in the western literature.
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| 3. |
- Zhang, Yong-Yuan, et al.
(författare)
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Hepatitis B virus DNA in serum and liver is commonly found in Chinese patients with chronic liver disease despite the presence of antibodies to HBsAg
- 1993
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Ingår i: Hepatology. - : Ovid Technologies (Wolters Kluwer Health). - 1527-3350 .- 0270-9139. ; 17:4, s. 538-544
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Tidskriftsartikel (refereegranskat)abstract
- Sera from 410 patients from the Wuhan area in the central part of China with the diagnosis of chronic liver disease were analyzed for markers of hepatitis B, C and D virus infections. All sera, plus liver biopsy specimens from 188 of the patients, were also tested for hepatitis B virus DNA by polymerase chain reaction. Sixty-eight percent were HBsAg positive in serum, whereas 29% showed markers of past hepatitis B virus infection. Hepatitis B virus DNA was detected in all HBeAg-positive sera but also in 58% of patients with HBe antibody. In the liver specimens of the corresponding patient groups, 97% and 78%, respectively, were hepatitis B virus DNA positive. However, more noteworthy was that of the HBsAg-negative/HBs-antibody positive patients 30% had detectable hepatitis B virus DNA in serum and 32% had hepatitis B virus DNA in liver tissue, whereas in a control group of healthy blood donors, of which 90% had HBs antibody, none was hepatitis B virus DNA positive. Our results demonstrate that among patients with chronic liver disease, infections with hepatitis B virus or hepatitis B virus-related virus(es) may frequently occur without being revealed by conventional serological methods. Hepatitis C and D viruses seem to be of only minor importance in the pathogenesis of chronic liver disease in this part of China.
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| 4. |
- Zhang, Yong-Yuan, et al.
(författare)
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Hepatitis C virus antibodies and hepatitis C virus RNA in Chinese blood donors determined by ELISA, recombinant immunoblot assay and polymerase chain reaction
- 1992
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Ingår i: APMIS : acta pathologica, microbiologica, et immunologica Scandinavica. - 1600-0463. ; 100:9, s. 851-855
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Tidskriftsartikel (refereegranskat)abstract
- Antibodies to hepatitis C virus (anti-HCV) were determined in Chinese blood donors from the city of Wuhan by a second generation ELISA screening test and a confirmatory recombinant immunoblot assay (RIBA II). Two materials of 281 and 222 sera were sampled under similar conditions in 1989 and 1990, respectively. The first collection of sera was sent to Sweden in lyophilized form, the second directly as fresh unfrozen sera. A high proportion (7.1%) of the lyophilized sera reacted positively in the anti-HCV screening assay, but only seven (2.5%) were positive by the RIBA confirmatory test. In four of these sera HCV-RNA could be detected by polymerase chain reaction (PCR) analysis. In the second material of fresh sera six reacted positively in the screening anti-HCV ELISA, but only one was RIBA positive and four were RIBA indeterminate. None of these sera was positive for HCV-RNA. Thus, the overall prevalence of anti-HCV among the 503 Chinese blood donors, as identified by RIBA, was 1.6%, and of HCV-RNA by PCR 0.8%. The confirmed antibody prevalence is higher than reported from the Western world. Caution about using data from the screening ELISA only, especially if sera have been handled in an unorthodox way, is emphasized.
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