Junnosuke Watanabe

Transmission of hepatitis C in an isolated area in Japan : community-acquired infection

Abstract Background/Aims: The spread of hepatitis C virus (HCV) infection not due to drug needle sharing or transfusion is largely unknown in communities. A search for risk factors for HCV infection in an endemic area might elucidate inapparent modes of transmission. Methods: We conducted screening for hepatitis virus markers and parenteral exposures to blood among 435 inhabitants in an isolated area known for its endemicity for non-A, non-B hepatitis and in a nonendemic area with 1542 inhabitants. Results: The prevalence of hepatitis B surface antigen was the same in both areas. The prevalence of antibody to HCV verified by the recombinant immunoblot assay was 32.4% in the highly endemic area and 2.3% in the nonendemic area ( P Conclusions: Folk remedies such as acupuncture and cutting of the skin using nonsterilized knives should be considered as possible routes of HCV transmission not associated with blood transfusion or sharing of drug paraphernalia.

Recombination and gene conversion-like events may contribute to ABO gene diversity causing various phenotypes

Abstract. We identified five different alleles, tentatively named ABO*O301, *O302, *R102, *R103, and *A110, in Japanese individuals possessing the blood group O phenotype. These alleles lack the guanine deletion at nucleotide position 261 which is shared by a majority of O alleles. Nucleotide sequence analysis revealed that *O301 and *O302 had single nonsynonymous substitutions compared with *A101 or *A102 responsible for the A1 phenotype. Analysis of intron 6 at the ABO gene by polymerase chain reaction-single-strand conformation polymorphism and direct sequencing revealed that *R102 and *R103 had chimeric sequences of A-O2 and B-O2, respectively, from exons 6 to 7. In the analysis of five other chimeric alleles detected in the same manner, we identified a total of four different recombination-breakpoints within or near intron 6. When 510 unrelated Japanese were examined, the frequency of the chimeric alleles generated by recombination in intron 6 or exon 7 was estimated to be 1.7%. In addition, we found that *O301, *A110, *C101, *A111, and 35% of *A102 had a unique A-B-A chimeric sequence at intron 6, presumed to originate from a gene conversion-like event. We had previously established that *A110 also had an A-O2-A chimeric sequence around nucleotide position 646 in exon 7. Thus this allele has an A-B-A-O2-A chimeric sequence from intron 6 to exon 7 probably generated by two different gene conversions. Similar patchwork sequences around nucleotide position 646 in exon 7 were observed in two other new alleles responsible for the Ax and B3 phenotypes. Thus, the site is presumably a hotspot for gene conversion. These results indicate that both recombination and gene conversion-like events play important roles in generating ABO gene diversity.

Predictive value of screening tests for persistent hepatitis C virus infection evidenced by viraemia : Japanese experience

In November 1989, Japanese Red Cross Blood Centres started screening for heaptitis C virus (HCV) with enzyme‐linked immunosorbent assay (Elisa) for the C100‐3 viral peptide as the first such nationwide programme in the world. Thereafter post‐transfusion non‐A non‐B hepatitis (PTNANBH) was reduced by 61–80%, but this was not as complete a success as our programme to prevent post‐transfusion hepatitis B by screening for high titer hepatitis B core antibody, which we began in the same period. In order to acquire more effective control of PTNANBH, the HCV core‐related antigen (GOR, N14) and second‐generation Elisa (Ortho2, Abbott2)and second‐generation antigen agglutination (PA, PHA) tests have been employed. Among 16,500 donors in 11 blood centers, 365 were serologically positive by at least one of these tests. Among these, HCV RNA was detected in 138 units and the remaining 227 were HCV RNA negatives. The effectiveness of these serological tests to detect HCV RNA‐positive status were analyzed. Passive haemagglutination and particle agglutination (PHA and PA) tests were highly effective to predict HCV viraemia among blood donors. Also, these tests can easily determine antibody titre. By either PHA or PA, all units with ≧212 agglutination titre (120 and 122 units) were HCV RNA positive and all agglutination‐positive units with serum alanine aminotransferase level higher than 35 Karmen units were HCV RNA positive. These results have formed the basis for implementing a more effective screening for HCV viraemia in blood donors, where effectiveness is defined as enhancing the protection of patients from post‐transfusion hepatitis C and providing higher quality information to achieve more effective donor counselling.

Seroepidemiology of HCV and HBV infection in northern China

SummaryThe HCVAb positive rate in normal population in Beijing was 2.1% and HBsAg positive rate was 2.5%. There is an increasing tendency in the aged group. Plasmapheresis might have been the major cause of HCV transmission in blood donors in the Hebei area. There was a high prevalence of HCVAb and HBsAg in chronic liver diseases in the Beijing area and the HCVAb-positive rate significantly increased corresponding to disease progression.

Effect of Donor Blood Screening for Anti-HCV Antibody by the Second-generation Passive Hemagglutination Test on the Incidence of Post-Transfusion Hepatitis

The aim of this study was to determine whether the second-generation anti-HCV antibody passive hemagglutination (PHA) test would offer more effective control of post-transfusion non-A, non-B hepatitis (NANBPTH). Firstly, the sensitivity and specificity of the first- and second-generation anti-HCV antibody tests were compared to HCV-RNA results by polymerase chain reaction (PCR) in 365 donor blood samples. Secondly, a prospective study to assess the effectiveness of second-generation PHA screening of 174 open-heart surgery patients was begun in May, 1992. PHA was positive in 98.6% of 138 donor samples with HCV-RNA, vs only 62.3% for enzyme-linked immunosorbent assay (ELISA). None of the open-heart patients seroconverted to HBV or HCV, although seven developed acute hepatitis. Screening with PHA resulted in a remarkable decrease in NANBPTH. However, there remain some risk factors for post-transfusion hepatitis to be clarified, perhaps involving a non-C hepatitis virus.

Three-band Nested Double PCR for Semiquantitation of Hepatitis C Virus in Donated Blood: Comparison with Antibody and Alanine Aminotransferase Level

Quantitation of hepatitis C virus (HCV)-RNA is now urgently required for clinical and epidemiological studies on HCV infection. We semi-quantified HCV- RNA by reverse transcription and a nested double polymerase chain reaction (ND-PCR) in the 5′ untranslated region (5′UTR). One, two, and three bands of amplified DNA derived from less than 50 RNA molecules, 50 to 2500 RNA molecules, and 2500 or more RNA molecules, respectively, were observed on gel electrophoresis. Among 12000 blood donors, 85 were HCV-RNA-positive by ND-PCR. HCV antibody titer was determined by second-generation particle agglutination (PA) tests. A positive correlation was found between antibody titer by PA testing and HCV-RNA quantity. We also observed a tendency for the ALT level to be lower in the one-band group and higher in the three-band group.