Epidemiology of blood donors in Japan, positive for hepatitis B virus and hepatitis C virus by nucleic acid amplification testing

Detection of hepatitis B virus DNA and HBsAg from postmortem blood and bloodstains

A large number of accidental virus infections occur in medical and non-medical workers exposed to infectious individuals and materials. We evaluated whether postmortem blood and bloodstains containing hepatitis B virus (HBV) are infectious. HBV-infected blood and bloodstains were stored for up to 60 days at room temperature and subsequently screened for hepatitis B surface antigen (HBsAg) and HBV DNA. In addition, HBV-positive postmortem blood was added to a cell line and the production of HBV virions was examined over a period of 7 days. HBsAg and HBV DNA were detected in all samples stored for 60 days at room temperature. HBV-positive postmortem blood successfully infected the cell line and progeny viruses were produced for up to 6 days. Thus, it is crucial that due care is taken when handling not only living material infected with HBV, as well as other harmful viruses, but also blood or body fluids from cadavers or medical waste.

A pilot study on screening blood donors with individual-donation nucleic acid testing in China

BACKGROUND

Nucleic acid amplification testing (NAT) is not yet obligatory in China for blood donor screening and the risk of enzyme immunoassay (EIA)-negative, NAT-reactive donations in Chinese blood donors has rarely been reported. The aim of this study was to screen a population of Chinese blood donors using a triplex individual-donation (ID)-NAT assay and assess the safety benefits of implementing NAT.

MATERIALS AND METHODS

Between 1st August, 2010 and 31st December, 2011 all donations at a Chinese blood centre were screened individually using the Procleix® Ultrio® assay, a multiplex NAT assay for the detection of hepatitis B virus (HBV) DNA, hepatitis C virus (HCV) RNA and human immunodeficiency virus-1 (HIV-1) RNA. All donations were also screened for HBsAg, anti-HIV and anti-HCV using two different EIA for each marker. Samples with discordant results between NAT and EIA were further tested with an alternative NAT assay (Cobas® TaqMan®). Potential yield cases (serologically negative/NAT-reactive donors) were further evaluated when possible.

RESULTS

During the study period a total of 178,447 donations were screened by NAT and EIA, among which 169 HBV NAT yield cases (0.095%) were detected. No N AT yield cases were found for HIV-1 or HCV. For the HBV NAT yield cases, follow-up results showed that 11 (6.51%) were probable or confirmed HBV window period infections, 5 (2.96%) were chronic HBV carriers and 153 (90.53%) were probable or confirmed occult HBV infections. There was a statistically significant difference between the NAT-positive rates for first-time vs repeat donations (0.472% vs 0.146%, respectively; P<0.001).

DISCUSSION

Our data demonstrate that the potential HBV yield rate was 1:1,056 for blood donations in the Zhejiang province of China. Implementation of NAT will provide a significant increment in safety relative to serological screening alone.

Genotypic polymorphisms of hepatitis B virus provide useful information for estimating geographical origin or place of long-term residence of unidentified cadavers

Increasing numbers of unidentified cadavers are a major problem. We have developed a new method for providing identification information that can determine the geographical origin or place of long-term residence of unidentified cadavers based on genotypic polymorphisms of hepatitis B virus (HBV) known to correlate with their geographical distribution. PCR of serum samples detected HBV DNA from 4 (3.9%) of 102 randomly selected Japanese forensic cadavers. Multiplex PCR did not detect multiple HBV genotypes from any single cadaver, confirming the absence of coinfection. Phylogenetic tree analysis based on a 485-bp mutant region of the HBV S gene successfully classified the HBV genotypes into A to J. Among 10 HBV-infected cadavers, 8 had genotype Ce/C2, a genotype prevalent in East Asia, and 2 had genotype Bj/B1, a Japanese-specific genotype. HBV genotypic polymorphisms correlate with the geographical distribution of the virus and thus provide important information for identifying unidentified cadavers infected with HBV.

Six-year pilot study on nucleic acid testing for blood donations in China

A six-year pilot study on nucleic acid testing for HBV, HCV and HIV-1 has been undertaken on sero-negative plasmas in mini-pool and individual donation testing at Shenzhen Blood Center. Of 307,740 sero-negative blood samples, 95 of 102 HBV DNA yields were confirmed positive, 80/95 (84.2%) were classified as occult HBV infection (OBI) and 15 (15.8%) as window period cases. Amongst OBIs, 45% carried anti-HBc only, 41.3% anti-HBc and anti-HBs and 13.7% anti-HBs only. HBV DNA yield was 1:3239. One HCV WP and one HIV-1 infected donations were detected. High residual risk was found in current blood donations screening in China.

Risk factors for mother-to-child transmission of hepatitis C virus: Maternal high viral load and fetal exposure in the birth canal

AIM

  Mother-to-child transmission (MTCT) is the major transmission pathway of hepatitis C virus (HCV) in children. However, its risk factors remain unsettled for introduction of putative intervention.

METHODS

  Pregnant women screened for HCV and MTCT in children born to antibody-positive mothers were prospectively studied in Tottori, Japan.

RESULTS

  Among 41 856 screened women, 188 (0.45%) were HCV antibody-positive, of whom 61% had detectable HCV RNA. While 10 of the 34 children (29%) born to high viral load (HVL: ≥6.0 × 10(5)  IU/mL) mothers were infected, none born to RNA-detectable but non-HVL mothers were infected (P < 0.001). MTCT among vaginally delivered children born to HVL mothers was analyzed. Children delivered after 4 h or more of labor were more frequently infected than were those born within 4 h of labor (P = 0.019). Premature rupture of fetal membranes was significantly more common in infected children than in uninfected children (P < 0.001). Durations of membrane rupture and labor were longer in infected children than in uninfected children (P = 0.008 and P = 0.040, respectively). Elective cesarean section that eliminates these risk factors, other than HVL, significantly reduced MTCT from nine of 22 (41%) to none of nine children (0%) (P = 0.032).

CONCLUSION

  Our data suggest that contamination of the fetus in the birth canal with infected maternal blood is a major risk factor for HCV MTCT, in addition to maternal HVL. To rationalize intervention by elective cesarean section, the natural history of infected children should be carefully evaluated.

Prevalence of hepatitis C virus infections and distribution of hepatitis C virus genotypes among Korean blood donors

BACKGROUND

Hepatitis C virus (HCV) remains a worldwide health-care burden. Prevalence rates vary and the distribution of genotypes depends on geographical location. Here, the recent prevalence of HCV infections and distribution of HCV genotypes among Korean blood donors were studied.

METHODS

Between February 2005 and December 2009, a total of 11,064,532 donors were screened for anti-HCV and 11,412,690 donors were screened for HCV RNA. HCV genotyping was conducted for 748 blood donors with HCV RNA by using the line probe assay (VERSANT HCV Genotype 2.0 Assay, Bayer Healthcare, USA) after amplification of the 5'-untranslated and core regions of the genome.

RESULTS

The anti-HCV prevalence was 0.16% (17,250/11,064,532). HCV RNA was detected in 959 out of the 11,412,690 donors (8.4/100,000). HCV RNA was more prevalent among women, donors who resided at harbor sites, and first-time donors. In addition, the prevalence of HCV RNA increased with age. The genotypes of 740 out of the 748 tested donors (98.9%) were identified. HCV genotype 1b (47.7%) and 2a/2c (35.0%) were dominant. Genotypes 2 (7.6%), 2b (2.3%), 3a (1.6%), 1a (1.3%), 1 (0.9%), 2v (0.5%), 1v (0.1%), and 3 (0.1%) were also identified. Genotype 4a/4c/4d (0.1%) was detected for the first time in one Korean blood donor.

CONCLUSIONS

The distribution of HCV genotypes in Korea has not changed remarkably, with the exception of genotype 4a/4c/4d. A periodic study to monitor the prevalence of HCV infections and the distribution of HCV genotypes is required to identify emerging genotypes in Korea.

Hepatitis B virus in transfusion medicine: still a problem?

Hepatitis B virus (HBV) has probably evolved with humans for nearly 35,000 years. HBV diversified into 9 genotypes (A-I) presenting specific features directing epidemiology, clinical expression and testing. Genotypes E and C are more infectious and carry higher risk of chronicity and cancer. HBsAg blood screening implemented 40 years ago enormously decreased the risk of transfusion transmission but the remaining risk requires extremely sensitive nucleic acid testing (NAT) to be removed. Limitations of the host immune system, the impact of immunodeficiency and the mechanisms utilised for viral persistence were recently identified. HBV replication produces excess HBsAg and infectious and defective viral particles but screening assays for HBsAg or viral particles alone do not allow fully efficient detection, making necessary screening for both. The host immune system fails to completely control the virus that escapes and persists unrecognized at very low levels or as immuno-selected variants. Variants may not be identified by assays, explaining false negative results. Specific mutations may affect post-transcriptional mechanisms including HBV RNA splicing. Asymptomatic HBV infected blood donors are at risk of long-term complications through mechanisms to be understood for appropriate counselling. Infectivity of occult HBV infection (OBI) by transfusion appears low, anti-HBc (anti-core antigen) only being more infectious than anti-HBs (anti-S protein) positive units.

Prevalence of amino acid mutation in hepatitis C virus core region among Japanese volunteer blood donors

It is not known whether there is a trend of increasing or decreasing incidence of new hepatitis C virus (HCV) infections in Japan. From the treatment point of view, it is important to verify HCV genotypes and the prevalence of treatment-resistant clones of HCV. At the Japanese Red Cross blood centers, all blood samples obtained from blood donation have been screened using serological methods and the minipool nucleic acid amplification testing. One hundred and fourteen donors have been identified over the past 10 years to be HCV RNA-only positive without detectable anti-HCV and were considered to be in the acute phase of HCV infection. There was a trend of decreasing incidence of such new infections among the blood donors. HCV RNA-only-positive samples were examined further for genotyping and HCV RNA quantitation. Genotype 2 (2a plus 2b) was predominant (78.2%) among them followed by genotype 1b (21.2%). Direct sequencing was carried out to detect the possible treatment-resistant mutant clones 70Q and 91M, clones with amino acid substitutions at positions 70 and 91 of the HCV core protein, respectively. 70Q and 91M were found regularly in donors with genotype 1b, but not in those with other genotypes. No particular endemic areas for the mutant clones were identified. There was no significant difference in the mean viral titer between the 70Q mutant type and the non-70Q wild-type. Even in newly infected people, the mutant clone 70Q was detected frequently.

Epidemiological survey of Japanese children infected with hepatitis B and C viruses

AIM

  The lack of a nationwide survey on hepatitis B virus (HBV) and hepatitis C virus (HCV) infections in Japan led us to investigate the epidemiological profiles of these infections among Japanese children.

METHODS

  We conducted a questionnaire survey of children (<20 years of age) infected with either HBV (n = 136) or HCV (n = 114), who visited 636 pediatric institutions in Japan from 2003 through 2005. Most HBV-infected subjects (94%) were born in 1986 or after when a nationwide immunization program for infants born to HBe antigen-positive carriers was initiated. The transmission routes were divided into five groups: maternal, horizontal (subdivided into intrafamilial, iatrogenic and other horizontal), and unknown transmission.

RESULTS

  Comparison of subjects born in 1990 or after and those born in 1989 or before, when anti-HBc and anti-HCV (c100-3) screening tests of blood donors began, showed a shift in the relative proportions of maternal, intrafamilial, iatrogenic, other horizontal, and unknown transmission from 52%, 19%, 4%, 7% and 19% to 70%, 14%, 6%, 1% and 9%, respectively, for HBV, which was statistically insignificant (P = 0.120), and from 14%, 0%, 76%, 4% and 7% to 89%, 2%, 4%, 0% and 5%, respectively, for HCV, which was statistically significant (P < 0.001). HBV horizontal transmission did not decrease in proportion. No transfusion-acquired HCV infection was reported in subjects born in 1993 or after.

CONCLUSION

  Maternal transmission is a prominent source of HCV infection among Japanese children. The implementation of measures to prevent HBV horizontal infection is also essential, and the present system of selective vaccination should be expanded to universal vaccination.

Declining hepatitis C virus (HCV) prevalence in pregnant women: impact of anti-HCV screening of donated blood

BACKGROUND

Screening blood donors for hepatitis C virus (HCV) antibody has effectively mitigated transfusion transmission of HCV. We conducted a post hoc analysis to clarify the impact of donor screening on a general population of reproductive-age females and their offspring.

STUDY DESIGN AND METHODS

Anti-HCV screening in Japan started in late-1989. In a cohort studied between May 1990 and November 2004, a total of 22,664 consecutive serum samples from pregnant women were screened for anti-HCV. Reactive samples were further tested for HCV RNA. Linear structural regression was applied to identify causal relationships.

RESULTS

Anti-HCV-reactive rates declined significantly by two measures. First, among women known to have been transfused, rates fell from 14.8% to 3.1% with the implementation of anti-HCV screening (p < 0.01). Nevertheless, this is 10 times higher than the 0.3% reactive rate seen in a similar cohort of nontransfused women. Second, rates fell from 1.8% among women born in 1955 or before to 0.3% for women born in 1966 or later (p < 0.01). Among 103 anti-HCV-reactive women, 31 (30%) had been transfused and another 17 (17%) had other identifiable risk factors. The remaining 55 (53%) had no clear risk factor. Blood transfusion accounted for 19% of anti-HCV acquisition, by path analysis. Only one infant in this cohort was vertically infected with HCV.

CONCLUSION

Anti-HCV screening of donated blood and hygienic improvements have markedly decreased HCV infection of pregnant women with a transfusion history; however, 70% of anti-HCV-reactive women were deemed to be infected via routes other than transfusion.

Age- and gender-specific distributions of hepatitis B virus (HBV) genotypes in Japanese HBV-positive blood donors

BACKGROUND

There are an increasing number of reports on the hepatitis B virus (HBV) genotype distribution in acute or chronic HBV-infected patients in Japan; however, reports on the HBV genotype of blood donors are few. To compare the HBV genotypes of hepatitis B surface antigen (HBsAg)-positive blood donors with infected patients, all the HBsAg-positive donors' genotypes were determined.

STUDY DESIGN AND METHODS

Data on Japanese blood donors from October 2006 to September 2007 were obtained from the Japanese Red Cross database. The number of available samples was 1979, and the HBV genotypes were determined in 1887 samples. The six major genotypes of HBV (A-F) were determined by enzyme-linked immunosorbent assay. The presence of the immunoglobulin M (IgM) antibody against the HBV core antigen was determined by enzyme immunoassay among all HBsAg-positive donors.

RESULTS

A significant difference in the HBV genotype distribution between donors and patients was in the C/B genotype ratio. The ratios were low in blood donors (2.0-3.9) and high in patients (5.3-18.2). The genotype B ratio increases from 13.8% in teenage donors to 42.4% in those in their 50s; however; the genotype C ratio decreases from 83.1% in teenage donors to 55.1% in those in their 50s. In both IgM antibody against hepatitis B core antigen and nucleic acid test-positive donors, genotypes A and B were restricted to male donors.

CONCLUSIONS

The age-specific distribution of HBV genotypes in Japanese blood donors was observed in the B/C genotype ratio. The gender-specific distribution of HBV genotype A, which originated from the US or Western countries, was observed in male Japanese donors.

Direct cytopathic effects of particular hepatitis B virus genotypes in severe combined immunodeficiency transgenic with urokinase-type plasminogen activator mouse with human hepatocytes

BACKGROUND & AIMS

Little is known about the direct cytopathic effect of hepatitis B virus (HBV) and its association with particular viral genotypes or genetic mutations. We investigate HBV genotype-related differences in viral replication, antigen expression, and histopathology in severe combined immunodeficiency transgenic with urokinase-type plasminogen activator mice harboring human hepatocytes.

METHODS

Mice were inoculated with wild-type of different genotype strains (3 for each HBV/A2, B1, and C2) recovered from preinfected-mice sera or patient sera.

RESULTS

Histologic analysis of mice infected with HBV/C2 for 22-25 weeks showed abundant ground-glass appearance of the hepatocytes and fibrosis in the humanized part of the murine liver owing to the activation of hepatic stellate cells mediated by oxidative stress through transforming growth factor-beta1 signaling, whereas neither was observed with HBV/A2 and B1. The HBV-DNA level in sera was the highest in mice infected with HBV/C2 compared with those with HBV/A2 and HBV/B1 (10(9), 10(7), and 10(4) log copies/mL, respectively, P < .05) during 6-8 weeks postinoculation. HB core-related antigen excretion had a similar trend among the genotypes, whereas secretion of HB surface antigen was more pronounced for HBV/A2 followed by HBV/C2 and much less for HBV/B1. Introduction of precore stop-codon mutation in the HBV/B1 caused a significant increase in viral replication, antigen expression, and a histopathologic picture similar to HBV/C2.

CONCLUSIONS

By using a humanized in vivo model, we show that different HBV genotypes and even particular mutations resulted in different virologic and histopathologic outcomes of infection, indicating that particular genetic variants of HBV may be directly cytopathic in immunosuppressive conditions.

A pilot study for screening blood donors in Taiwan by nucleic acid amplification technology: detecting occult hepatitis B virus infections and closing the serologic window period for hepatitis C virus

BACKGROUND

Blood donors in Taiwan currently are screened for hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) infection by immunoassay. The risk of enzyme immunoassay (EIA)-negative, nucleic acid amplification technology (NAT)-reactive donations is not well understood. This study aimed to screen for such donors in Taiwan by a multiplex test (cobas TaqScreen, Roche) on a commercially available NAT system (cobas s 201 system, Roche).

STUDY DESIGN AND METHODS

NAT was performed on donors without prescreening in pools of six and NAT-reactive pools were then resolved to the single donation. Individual-donor NAT-reactive samples were discriminated by a commercially available polymerase chain reaction (PCR)-based diagnostic assay (COBAS AmpliScreen, Roche). Samples with EIA- and NAT-discordant results were investigated with supplemental serologic and confirmatory tests. Each sample taken from follow-up of HBV NAT yield cases was tested for HBV serologic profile, NAT, and viral load. The sensitivity and performance efficacy were also evaluated.

RESULTS

The 95 percent limit of detection (LOD) for HBV, HCV, and HIV were 5.09, 11.83, and 62.53 IU per mL, respectively. Among 10,727 seronegative donations, 12 HBV NAT yield cases (0.11%) and 1 HCV NAT yield case (0.01%) were detected. Follow-up results for 1 to 8 months showed that the HCV yield case was a window case and all HBV NAT yield cases were occult carriers.

CONCLUSION

The use of NAT detected occult HBV and reduced HCV window period. The yield rate, especially occult HBV, was 10- to 100-fold higher than that in developed, HBV nonendemic countries. Therefore, NAT implementation for routine donor screening in a more cost-effective manner should contribute to safer blood transfusion in Taiwan.

International collaborative study proposal for the characterization of occult hepatitis B virus infection identified by nucleic acid or anti-HBc screening

The International Society of Blood Transfusion (ISBT) transfusion-transmitted infections (TTI) working party is proposing to undertake an international collaborative study aimed at understanding occult hepatitis B infection by molecular and immunological characterization, determining infectivity by transfusion and clinical relevance of this newly identified condition. This article provides information to the transfusion community and aims to recruit potential collaborators for the study. Further information can be obtained from the author or the ISBT TTI working group website (http://www.isbt-web.org).

Preliminary results of HBV DNA testing of Polish haemophilia patients--lack of occult HBV infection

Identification of hepatitis B virus (HBV) infection in the absence of surface antigen (HbsAg) became possible with the introduction of HBV DNA detection methods. Such occult HBV infection was diagnosed recently in about half of the Japanese HBsAg-negative haemophilia patients. The aim of our study was to assess the prevalence of occult HBV infection in Polish severe haemophilia population on the sample of 115 haemophilia A and B patients (mean age 34.9 +/- 10.9) treated with non-virus inactivated clotting factor preparations before 1995. HBV DNA was detected in nine HBsAg-positive patients (7.8%). The mean HBV DNA load was 72,800 IU mL(-1) (250-400,000 IU mL(-1)). Hepatitis C virus (HCV) RNA was found in six out of nine HBV-positive patients. In conclusion, HBV DNA was identified only in HBsAg-positive patients. Unlike in Japan, the frequency of occult HBV infection in Polish haemophilia population seems extremely rare or absent.

Heterogeneity of Hepatitis B Virus Genotype D in Japan

OBJECTIVE

Hepatitis B virus (HBV) genotypes B and C are predominant in Japan. Previously, we reported that approximately 9% of HBV carriers in the Ehime area of western Japan were infected with genotype D (HBV/D) and their sequences closely related. Recently, serum samples from 3 patients with chronic HBV/D infections living in Tokyo and the surrounding area became available for testing. The purpose of this study was to determine whether the HBV/D isolates from these different areas of Japan are closely related.

METHODS

Of the 3 Tokyo area patients infected with HBV/D, 2 had chronic hepatitis, and 1 had hemophilia with a history of frequent coagulation factor injections. The complete HBV/D genome sequences of each were determined, and compared with those of subjects from the Ehime area.

RESULTS

All 3 HBV/D sequences had a genomic length of 3,182 bases, and the hepatitis B surface antigen subtype was ayw3. Phylogenetic analysis revealed that the 1 of the HBV/D isolates was closely related to the isolates from Ehime Prefecture, while 1 was similar and 1 was clearly distinct.

CONCLUSION

Our results indicate that HBV/D infections in Japan are heterogeneous.