Incidence of hepatitis E virus infection among blood donors in a high endemic area of Central Italy

In Europe, autochthonous hepatitis E virus (HEV) infection is mainly a foodborne zoonosis, but it is also transmitted by blood transfusion. Despite the numerous prevalence surveys, only a few studies have investigated HEV incidence. We aimed to determine HEV incidence and risk factors among blood donors in a hyperendemic area in Central Italy. Of 296 blood donors who had tested HEV negative in two previous seroprevalence surveys in L'Aquila, 198 agreed to undergo at least another blood sampling for estimating HEV incidence nearly 2 years after the prevalence surveys. Ten newly acquired infections were detected, yielding an overall incidence of 2.1/100 person‐years (95%CI: 1.0‐3.9), with an estimated participant's cumulative probability of becoming HEV infected of 6.5% (95%CI: 3.5‐12.0) at 4 years after enrolment. Seven newly infected blood donors were IgG positive only, two were IgM positive (one also IgG positive) and one was HEV RNA positive only, harbouring subtype 3c. Incident infection was most strongly associated with eating game meat, raw‐dried pork liver sausage and raw‐dried wild boar sausage. None of these exposures was statistically significant, even if eating raw‐dried wild boar sausage approached significance (P = 0.06). The HEV incidence we found was considerable compared with other similar studies. The nearly significant association of incident infection with wild boar and other game meat consumption was in agreement with the 3c subtype isolation in the viremic donor. However, beyond eating habits, also other exposure sources are likely important in hyperendemic areas, where incidence and risk exposure studies need to be undertaken for effectively preventing HEV transmission.     

A nationwide survey for prevalence of hepatitis E virus antibody in qualified blood donors in Japan

Background and Objectives In previous studies, we reported the transmission of hepatitis E virus (HEV) by transfusion, and the frequent detection of HEV markers in Japanese blood donors with elevated ALT levels. For the current study, we carried out a nationwide survey of the prevalence of IgG anti‐HEV in qualified blood donors throughout Japan. Materials and Methods The 12 600 samples from qualified blood donors were collected from seven blood centres (1800 per centre) representing nearly all regions of Japan. Samples were from age‐ and sex‐matched blood donors who tested negative for all the current blood screening tests. The samples were screened using the in‐house IgG anti‐HEV ELISA. Sequentially, the positive samples were tested by the commercial IgG anti‐HEV ELISA. Results Of 12 600 samples, 431 (3·4%) were regarded as positive for IgG anti‐HEV. The prevalence of IgG anti‐HEV was higher in eastern Japan (5·6%) than in western Japan (1·8%) (P < 0·001), and was also age‐dependent and higher in men (3·9%) than in women (2·9%) (P = 0·002). Conclusion The spread of the domestic infection of HEV was observed in qualified blood donors in Japan. A higher prevalence of IgG anti‐HEV was observed in male donors, older donors and in donors residing in eastern Japan. Further studies are necessary to clarify the potential risk of transfusion–transmission of HEV in Japan.     

Prevalence of markers of hepatitis B virus infection or vaccination in HBsAg-negative subjects

Background.

The implementation of mass vaccinations against hepatitis B virus (HBV) has significantly reduced the prevalence of HBsAg-positive subjects. At the same time, the prevalence of the other markers of infection has decreased, but there has been an increase in the percentage of subjects with markers of a successful vaccination. It has been suggested that increasing immigration from countries in which this virus is highly endemic is changing the epidemiology of HBV infection. The aim of this study was to assess the prevalence of the serological markers of HBV in Italian and non-Italian HBsAg-negative subjects.

Materials and methods.

In the years 2007–2008, 8,018 samples from HBsAg-negative subjects (7,521 Italians and 497 non-Italians) were received for detection of anti-HBs and/or anti-HBc. The findings in the 1,358 samples from candidate blood donors were compared with those obtained in 1991 and 1999.

Results.

The rate of anti-HBc positivity was 18.3% in the Italian samples and 32.8% in the non-Italian samples; the corresponding percentages of anti-HBs/anti-HBc positive samples (indicating past infection), anti-HBs positive only samples (vaccination) and anti-HBc positive only were, 11.3% vs. 22.5%, 25.8% vs. 17.2%, and 6.9% vs. 9.9% in Italians and non-Italians, respectively. The differences were more marked when stratified by age. In relation to candidate blood donors, simultaneous positivity for anti-HBs and anti-HBc decreased from 11.0% in 1991 to 8.1% in 1999 and 3.9% in 2007–2008, whereas isolated anti-HBs positivity increased from 2.2% in 1991 to 21.4% in 1999 and 42.9% in 2007–2008.

Conclusions.

The frequency of markers of past infection among Italians has decreased over time as a result of mass vaccination and is significantly lower than that observed in non-Italians. The increasing number of immigrants from countries in which HBV is highly endemic is changing the epidemiology of HBV infection in Italy.     

Hepatitis B virus blood screening: impact of nucleic amplification technology testing implementation on identifying hepatitis B surface antigen non-reactive window period and chronic infections

Background Despite improvements in hepatitis B surface antigen (HBsAg) test sensitivity, post‐transfusion hepatitis B virus (HBV) infection still occurs because HBsAg is undetectable during the early window phase (WP) of the infection, in the convalescence core window phase of the infection, or in serologically silent chronic hepatitis or in mutant forms of HBV. HBV‐DNA screening using high sensitivity nucleic amplification technology (NAT) assays has recently been introduced to reduce the residual risk of transmission of HBV by transfusion of blood components. Materials Over 1 year 75 063 donations were individually screened for HBV‐DNA by the Ultrio Procleix assay on the Tigris platform. The donations were collected in the Latium region, an area of the central Italy, and they accounted for the 40% of the total blood units collected in this area per year. The initial reactive samples were re‐tested and confirmed by the discriminatory HBV assay. Additional HBV serological markers were also performed. Suspected WP infections were followed‐up to monitor the development of the immune response. All HBV‐DNA‐positive donors were called back to check up their infectious status. Results The results of testing the 75 063 donations are: 33 donations HBsAg positive, 31 out of them HBV‐DNA‐positive and two HBV‐DNA negative; 22 donations HBsAg‐negative but HBV‐DNA positive with low viral load. Six of the 22 were found to be consistently HBV‐DNA reactive whereas the remaining 16 donations showed inconsistent results on multiple NAT retesting. One WP infection was confirmed by the follow‐up of the donor for 3 months following the index blood donation. Conclusions In the donor population of the Latium region, NAT screening has revealed a higher than expected number of donors who were HBsAg non‐reactive but HBV‐DNA‐positive with three donors showing HBV‐DNA as the only marker of infection. The adoption of genome screening has increased the safety of the blood supply and has also contributed to the protection of donor health by identifying either WP or clinically silent infections.     

Analysis of hepatitis G virus infection markers in blood donors and patients with hepatitis

The incidence and clinical significance of hepatitis G virus (HGV) is still not fully known. The aim of our study was to assess the frequency of HGV RNA and antibody to HGV E2 protein (anti-E2) in Polish blood donors and patients with hepatitis, and to compare the sequence of HGV clones with those reported by others. Two-hundred and nineteen blood donors and 83 patients with hepatitis were studied. HGV was detected in 3.2% and anti-E2 in 24.2% of blood donors and in 26.5% and 8.4% of patients with hepatitis, respectively. HGV was detected as a co-infection with HCV in four of 18 patients with chronic hepatitis, in four of 16 patients with acute hepatitis and in one of six patients with fulminant liver failure (FLF), and as a co-infection with HBV in one of six patients with FLF and in three of 10 patients with chronic hepatitis. In non-A–C hepatitis, eight of 23 patients with acute hepatitis and one of four patients with FLF were positive for HGV but all 10 patients with chronic cryptogenic hepatitis were negative. In the follow-up studies of patients with HGV alone, a correlation with viraemia and clinical symptoms was observed in two patients, but in three others HGV RNA was detected in spite of clinical resolution. Two HGV clones were sequenced, and the sequence of the HGV helicase region of the HGV isolates from donor and patient were homologous to those described by others. Hence, the frequency of HGV RNA in blood donors is similar to that obtained in other countries but the anti-E2 (marker of a past infection) frequency is higher. The incidence of HGV RNA and anti-E2 in hepatitis patients suggests that HGV plays a role in liver pathology, but careful analysis of individual cases does not confirm this.     

Prevalence and screening costs of hepatitis C virus among Ugandan blood donors

BACKGROUND: Screening donated blood for hepatitis C virus (HCV) is important for HCV prevention and is routinely practiced in North America and Europe. However, in many African countries little is known about HCV prevalence or cost-effectiveness of HCV antibody (anti-HCV) screening. METHODS: We investigated 2592 plasma specimens collected consecutively from blood donors in central Uganda in 1999. Routine screening by the blood bank included human immunodeficiency virus (HIV), hepatitis B surface antigen (HBsAg), and syphilis. To assess HCV prevalence and cost-effectiveness of testing, specimens were additionally tested for anti-HCV IgG by enzyme immunosorbent assay (EIA). Specimens repeatedly reactive (RR) on EIA were tested with a recombinant immunoblot assay (RIBA). RESULTS: Overall, 107 (4.1%) specimens were HCV EIA RR. Fifteen EIA RR specimens (0.6%, 95% confidence interval = 0.3-0.9%) were RIBA positive and 47 (1.8%) were RIBA indeterminate. Most (80%) RIBA-positive specimens were non-reactive for HIV, HBsAg, and syphilis. RIBA positivity was not associated with donor age, sex, number of donations, HIV, or HBsAg positivity. Costs of screening donors for anti-HCV by using EIA were estimated at US Dollars 782 per potential transfusion-associated HCV infection (exposure to RIBA-positive blood) averted. CONCLUSIONS: Current screening tests for other infections are ineffective in removing HCV-positive donations. Testing costs are considerable; cost-effectiveness of identifying HCV-infected donors will be critical in decision making about HCV screening in Uganda.     

Occult hepatitis B virus infection: a covert operation

Summary. Detection of occult hepatitis B requires assays of the highest sensitivity and specificity with a lower limit of detection of less than 10 IU/mL for hepatitis B virus (HBV) DNA and <0.1 ng/mL for hepatitis B surface antigen (HBsAg). This covert condition is relatively common in patients with chronic hepatitis C virus (HCV) that seems to exert some influence on the replicative capacity and latency of HBV. Detection of virus‐specific nucleic acid does not always translate into infectivity, and the occurrence of primer‐generated HBV DNA that is of partial genomic length in immunocompetent individuals who have significant levels of hepatitis B surface antibody (anti‐HBs) may not be biologically relevant. Acute flares of alanine aminotransferase (ALT) that occur during the early phase of therapy for HCV or ALT levels that remain elevated at the end of therapy in biochemical nonresponders should prompt an assessment for occult hepatitis B. Similarly, the plasma from patients with chronic hepatitis C that is hepatitis B core antibody (anti‐HBc) positive (±anti‐HBs at levels of <100 mIU/mL) should be examined for HBV DNA with the most sensitive assay available. If a liver biopsy is available, immunostaining for hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg) should be contemplated and a portion of the sample tested for HBV DNA. This is another reason for optimal collection of a specimen (e.g. two passes with a 16‐guage needle under ultrasound guidance). Transmission of HBV to immunosuppressed orthotopic liver transplant recipients by donors with occult hepatitis B (OHB) will continue to occupy the interests of the transplant hepatologist. As patients with OHB may have detectable HBV DNA in serum, peripheral blood mononuclear cells (PBMC) and/or liver that can be reactivated following immunosuppression or intensive cytotoxic chemotherapy, the patient needs to be either monitored or treated depending on the pretreatment serological results such as an isolated anti‐HBc reaction or a detectable HBV DNA.     

Frequency and distribution of hepatitis B virus genotypes among eastern Indian voluntary blood donors: Association with precore and basal core promoter mutations

Aim:  To screen hepatitis B virus (HBV) genotypes and associated basal core promoter (BCP; T1762/A1764) and precore (PreC; A1896) mutations among the HBV surface antigen (HBsAg) positive voluntary blood donors in eastern India.
Methods:  HBV genotypes, BCP and PreC mutations of 141 HBsAg positive voluntary blood donors were determined by the restriction fragment length polymorphism (RFLP) method and a phylogenetic tree was constructed from surface (S) gene region sequences of representative HBsAg positive donors to confirm the results.
Results:  HBV/D was the most predominant (79, 56.0%) genotype followed by HBV/C (33, 23.4%) and HBV/A (29, 20.6%). HBV/C infected blood donors are mostly young (18–25 years). The occurrence of BCP mutation was found to be significantly higher in HBV/C (24, 72.7%) than in HBV/A (7, 24.1%, P  < 0.001) and HBV/D (17, 21.5%, P  < 0.001), whereas PreC mutation was more frequent in HBV/D (28, 35.4%) than in HBV/C (9, 27.3%). However, the simultaneous presence of BCP and PreC mutations was more common in HBV/C (8/33, 24.2%), followed by HBV/D (6/79, 7.6%).
Conclusion:  In addition to HBV/D and HBV/A, a significant proportion of HBV/C (23.4%) was also present among the voluntary blood donors from eastern India, most frequently in the 18–25 year age group. BCP mutation was more common in HBV/C infected donors.     

Seroprevalence of human immunodeficiency virus, hepatitis B and C viruses and syphilis among blood donors in Koudougou (Burkina Faso) in 2009

Background

The high prevalence of numerous transfusion-transmitted infectious diseases such as human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV) and syphilis in sub-Saharan Africa affects the safety of blood for recipients. This study was undertaken with the aim of determining the seroprevalence of HIV, HCV, HBV, syphilis and socio-demographic risk factors associated with blood donation in a new regional blood transfusion centre in Burkina Faso.

Material and methods

Sera samples were screened for hepatitis B surface antigen (HBsAg), antibodies to HCV, HIV types 1 and 2 and to Treponema pallidum using enzyme-linked immunosorbent assays and Rapid Plasma Reagin test (RPR) respectively. All the reactive samples for HIV, HBsAg, and HCV were confirmed using a second enzyme-linked immunosorbent assays. Antibodies to Treponema pallidum were confirmed with a Treponema pallidum haemagglutination test (TPHA).

Results

From the total of 4,520 blood donors in 2009, 1,348 (29.82%) were infected with at least one pathogen and 149 (3.30%) had serological evidence of multiple infections. The overall seroprevalence rate of HIV, HBV, HCV and syphilis was 2.21%, 14.96%, 8.69% and 3.96%, respectively. Among blood donors with multiples infections, the most common dual or triple combinations were HBsAg-HCV (1.39%), HBsAg-syphilis (0.66%) and HBsAg-HCV-syphilis (0.11%). The highest prevalences of HBsAg and HIV were found among blood donors from rural areas and in the age groups of 20–29 years and >40 years old, respectively.

Conclusion

HBV and HCV remain the greatest threats to blood safety in Burkina Faso. Strict selection and retention of voluntary, non-remunerated low-risk blood donors are recommended to improve blood safety in the regional blood transfusion centre of Koudougou.     

广州地区无偿献血者戊型肝炎病毒感染流行病学调查

目的 调查广州地区无偿献血者的戊型肝炎病毒(hepatitis E virus, HEV)感染情况。方法 2017年4月-2018年4月间收集了5 552名广州血液中心无偿献血者的血液样本,采用酶联免疫吸附法(enzyme linked immunosorbent assay, ELISA)检测抗-HEV IgG抗体(HEV IgG)、抗-HEV IgM抗体(HEV IgM)和HEV抗原(HEV Ag),采用χ²检验分析年龄、性别、民族、职业和ALT等因素分别与HEV IgG和IgM抗体阳性的相关性,采用多因素Logistic回归分析判辨HEV感染的独立风险因素。结果 HEV IgG、IgM和HEV Ag的阳性率分别为20.05%(1 113/5 552)、0.76%(42/5 552)和0.04%(2/5 552)。年龄和民族是HEV IgG和HEV IgM阳性率的独立风险因素:HEV阳性率随着年龄增长而增大(IgG OR=1.089, 95%CI: 1.080-1.098, P<0.001; IgM OR=1.055,95%CI: 1.028-1.084, P<0.001);壮族的HEV IgG和IgM阳性率(32.69%, 7.69%)高于汉族(19.89%, 0.70%),差异有统计学意义(IgG OR=2.052, 95%CI: 1.103-3.819, P=0.023; IgM OR=12.029, 95%CI: 4.067-35.580, P<0.001)。此外,我们还发现职业是HEV IgG阳性率的独立风险因素,学生是阳性率最低的人群。结论 广州地区无偿献血者中HEV抗体阳性率较高,且在不同人群中感染情况不同,为输血传播HEV的风险评估提供基础数据。     

襄阳地区无偿献血者乙型肝炎病毒核酸检测效果分析

目的:分析核酸检测(NAT)献血者乙型肝炎病毒(HBV)结果,探讨血站全面开展NAT的必要性。方法:对我站酶免检测无反应性标本,采用PCR-荧光法进行NAT检测,NAT有反应性标本做HBV DNA定量和乙肝"两对半"检测。结果:NAT 31 443份标本,有反应49例(0.16%),其中,HBV DNA定量检测有反应性标本30例,"两对半"定性实验结果为22例HBsAg有反应性,14例HBsAg为临界值的标本,且其中32例合并HBeAb、HBcAb有反应性;13例HBsAb、HBeAb或HBcAb有反应性。结论:NAT能够在一定程度上弥补ELISA方法的局限性,有效缩短窗口期,防止亚型变异或者隐匿性肝炎漏检的风险,有必要在血站全面开展。     

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).     

Occult hepatitis B virus infection in hematopoietic stem cell donors in a hepatitis B virus endemic area

BACKGROUND/AIMS: The acquisition of hepatitis B virus (HBV) infection following organ transplantation from donors with occult HBV infection is an important cause of morbidity and mortality. The aim of this study is to determine the prevalence of occult HBV in allogeneic hematopoietic stem cell (HSC) transplantation donors. METHODS: We performed a retrospective study on 124 consecutive hepatitis B surface antigen negative HSC donors. Their serum samples were analyzed by PCR for the pre-S/S, pre-core/core and X regions of the virus. Samples reactive by at least two PCR assays were considered HBV-DNA positive. RESULTS: Nineteen of the 124 HSC donors (15.3%) had occult HBV infection. Sixteen of these 19 donors with occult HBV infection (84.2%) tested positive for hepatitis B core antibody while 78 of 105 subjects (74.3%) without occult HBV infection were also positive (P=0.56). Fourteen of the 19 donors (73.7%) with occult HBV infection tested positive for hepatitis B surface antibody while 67 of the 105 subjects without occult HBV infection were also positive (P=0.45). CONCLUSIONS: The prevalence of occult HBV infection among HSC donors in Hong Kong is high. Anti-HBc and anti-HBs status had no significant correlation with the presence of occult HBV infection.     

献血员隐匿性乙型肝炎病毒感染的分子流行病学

目的 了解献血员中隐匿性HBV感染的发生率,从S基因变异角度探讨隐匿性HBV感染可能的分子机制.方法 收集经血站筛查HBsAg阴性的合格献血员血浆594份,ELISA法检测HBV血清学标志物,套式PCR检测血清HBV DNA.对筛查出的隐匿性HBV感染者再次用雅培试剂定量检测HBV血清学标志物,并对其S区进行测序,发现可能与HBV隐匿性感染有关的变异位点.随机收集11例HBsAg阳性的HBV感染者作为阳性对照,对其S区进行测序,比较其与隐匿性HBV感染之间的关系.结果 在594例献血员中有15例为隐匿性HBV感染,隐匿性HBV感染的发生率为2.5％.未发现HBV血清学标志物检测结果与隐匿性HBV感染有相关性.15例隐匿性HBV感染者中有10例进行了S区测序,结果HBV均有不同程度的变异,其中3例在“a”决定簇内出现氨基酸突变,分别为1126T(1例)、T140I(2例).与隐匿性HBV感染者相比,阳性对照在“a”决定簇内仅出现了1例T131N变异.结论 常规检测HBsAg阴性的献血员中存在隐匿性HBV感染,且这些病毒可能存在变异.     

Estimation of the risk of hepatitis B virus,hepatitis C virus and human immunodeficiency virus infectious donations entering the blood supply in England, 1993-2001

BACKGROUND AND OBJECTIVES: The frequency of hepatitis B virus (HBV), hepatitis C virus (HCV) or human immunodeficiency virus (HIV) infectious donations entering the blood supply in England is too low to monitor using observational studies. The expected frequency of infectious donations can be estimated and these estimates may be used to contribute to monitoring of blood safety and used in the design of strategies to decrease the risk of transfusion-transmitted infections. MATERIALS AND METHODS: The prevalence and incidence of hepatitis B surface antigen (HBsAg), and antibodies to HCV and HIV (anti-HCV and anti-HIV, respectively) in donors in England, between 1993 and 2001, were used together with data about the length of negative 'window-periods' of current assays for each of these markers and data about test performance, to estimate the number of infectious donations that enter the blood supply. The risks were calculated separately for donations from new donors and from repeat donors, and for the three time periods 1993-95, 1996-98 and 1999-01. RESULTS: The estimated frequency of infectious donations entering the blood supply in England, between 1993 and 2001 was 1 in 260,000 for HBV and 1 in 8 million for HIV. For HCV, the frequency of infectious donations was 1 in 520,000 during 1993-98 and fell to 1 in 30 million during 1999-2001 when all donations were tested for HCV RNA. The frequency of HBV- and HCV-infectious donations entering the blood supply fell over these 9 years: the frequency of HIV-infectious donations remained essentially unchanged. The risk from donations from new donors was found to be approximately sevenfold higher than the risk from donations from repeat donors. CONCLUSIONS: The risks of HBV-, HCV- or HIV-infectious donations entering the blood supply in England are very low, and have decreased since 1993. Although the accuracy of these estimates is imperfect, mainly owing to uncertainty in some assumptions and to small numbers of infections, they provide some quantification of the risk of HBV, HCV or HIV transmission by transfusion, and allow comparison of the magnitude of these risks for each infection and over time. The methods we have used have been developed and improved from previously published methods.     

Determination of hepatitis B virus DNA incidence, viral load, and mutations in blood donors with HBsAg and anti-HBs-negative serology and antibodies to hepatitis B core antigen

BACKGROUND: The aim of the present study was to determine hepatitis B virus DNA incidence, viral load, and mutations in blood donors with HBsAG and anti-HBs negative serology and antibodies to hepatitis B core antigen. METHODS: Blood samples were collected from 1000 blood donors with HBsAg-negative test results. Anti-HBc total screening was performed using the ELISA method. HBsAg-negative/anti-HBc total-positive samples were tested for anti-HBs, anti-HBc IgM, HBeAg, and anti-HBe. Samples with isolated anti-HBc were determined for viral load of HBV DNA using real-time PCR. RESULTS: Anti-HBc total was established as positive in 200 (20%) of the 1000 blood donors. While anti-HBs was negative in 59 (29.5%) of the 200 anti-HBc-positive samples, it was found to be positive in 141 (70.5%) of them. All of the other hepatitis B markers were negative in all of the anti-HBs-negative samples. HBV DNA was not detected in the sera of the isolated anti-HBc-positive blood donors with real-time PCR. CONCLUSION: Although we could not detect HBV DNA in the sera of the isolated anti-HBc-positive blood donors, findings in the literature suggest that anti-HBc testing should be used in combination with HBsAg for the screening of blood donors to reduce risk. After that, the most appropriate algorithm to follow can be HBV DNA screening of donors.     

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

BACKGROUND AND OBJECTIVES: The Japanese Red Cross screens seronegative blood donors by nucleic acid amplification testing (NAT) for hepatitis B, hepatitis C and human immunodeficiency virus-1 markers. NAT-positive donors thus identified seemed to have a different infectious background from serologically positive donors. The purpose of our study was to characterize this background in the hepatitis B virus (HBV) and hepatitis C virus (HCV) NAT-positive donors. MATERIALS AND METHODS: Some 328 HBV DNA-positive and 44 HCV RNA-positive donors were detected by NAT testing of seronegative blood donors. These were characterized regarding age, gender and genotype of HBV and HCV. RESULTS: Those who were HBV NAT-positive were mainly young, in particular teenage girls. In Japan, genotypes C and B have previously been dominant, but recently genotype A has increased, and genotype H was recently detected. In HBV NAT-positive donors, the rate of genotype A was high (12.2%) compared with patients in hospital (1.7-2%). Donors who were HCV NAT-positive were also young, but mostly men in their twenties. The ratio of genotype 1b to 2a or 1b to 2b in HCV NAT-positive donors differed from that of hospitalized patients in Japan. We did not find genotype 1a, which is dominant in the USA. CONCLUSIONS: The high-risk donors detected by NAT were mainly young, with a different distribution of genotypes from that of hospitalized patients, regarding both HBV and HCV. The rare HBV genotype H has been found for the first time in Japan. The findings reflect the present spread of hepatitis viruses B and C.