Hepatitis B Virus Infection In Blood Donors Research Articles

Serological and Molecular Characterization of Occult HBV Infection in Blood Donors from South Italy.

Despite good vaccine coverage and careful blood donor selection policies, hepatitis B virus (HBV) is still the most frequent viral infection among blood donors (BDs) in Italy, mostly in the occult form (OBI). We studied the virological features of OBI in BDs from South Italy by serology, molecular testing for HBV-DNA, and sequencing for HBV genotypes and mutations. One hundred and two samples from 95 BDs (22.1% first time, 87.9% regular, median age 57 years) positive for HBV-DNA and negative for HBsAg were retrospectively analyzed. HBV biomarkers were detected in 96.9% (anti-HBc in 44.2%, anti-HBc plus anti-HBs in 49.5%, anti-HBs alone in 3.2%). No risk factor was declared by 45.3% of donors. HBV-DNA levels were very low (median: 7 IU/mL). All samples harbored HBV genotype D and single or multiple mutations in the S gene were found in 28/36 sequences analyzed and in 75% of donors. Mutations were unrelated to gender, donor group or serological patterns. An HBsAg assay with enhanced sensitivity was positive in samples from seven donors (7.4%), two of which negative for HBV-DNA by real-time PCR. OBI still represents a risk for HBV transmission from blood donations; screening by highly sensitive serological and molecular assays is warranted.

Re-Entry Evaluation of Chinese Blood Donors with Unconfirmed Hepatitis B Screening Results.

The hepatitis B virus (HBV) remains a high priority for Chinese blood banks due to the high prevalence of infection. HBV blood safety has been significantly improved by the implementation of highly sensitive and specific serological and molecular HBV screening assays. The multiplication of viral markers tested and the ever-increasing analytical sensitivity of the tests can make the interpretation of the results difficult. False-positive or indeterminate results may lead to permanent donor deferrals and conflicts between donors and blood banks. To avoid blood shortages, blood services aim to limit unnecessary donor losses by developing procedures for the re-entry of donors temporarily deferred due to an unconfirmed HBV reactivity. The development of such procedures based on donor follow-up and HBV confirmation remains limited. A review of the scarce data available revealed considerable heterogeneity in testing methods and re-entry algorithms, limited validation studies, and a lack of accurate assessment of the residual infectious risk potentially associated with donor re-entry. In conclusion, systematic and widely validated confirmatory testing and prolonged follow-up are essential for safe re-entry of temporary deferred donors. Standardization of HBV testing methods and the establishment of dedicated expert laboratories are needed because of the complexity of HBV infection in blood donors.

Prevalence of viral hepatitis B markers among blood donors in the Republic of Guinea

The problem of transfusion safety in relation to parenteral viral hepatitis still remains relevant. Viral hepatitis B (HB) remains the most common viral infection transmitted through transfusion procedures. One of the natural phases of chronic hepatitis B (CHB) is occult hepatitis B infection (OBI), characterized by an undetectable HBsAg (regardless of the other serological markers content) in the presence of hepatitis B virus (HBV) DNA in the liver tissue and an extremely low, up to undetectable, level of viral load in the blood. In the Republic of Guinea, as in most countries on the continent, the prevention of HBV transmission through transfusion is still based on HBsAg serological testing of donors only. In this connection, OBI remains as a potential threat to blood transfusion safety. Detection of HBV DNA is a reliable preventive measure against transmission of the virus from donors with HBsAg-negative HBV infection, especially in highly endemic regions. In this regard, the study was conducted to substantiate recommendations for improving blood safety against the background of significant HBV prevalence in the Republic of Guinea.The aim of the work was the evaluation of serological and molecular markers of HBV infection in blood donors in the Republic of Guinea. We examined 250 blood samples obtained from donors living in Conakry, Republic of Guinea. Samples were tested for the presence of serological (surface antigen, HBsAg; antibodies (ABs) to surface (anti-HBs IgG) and core (anti-HBc IgG) antigens) and molecular (DNA) markers of HBV infection. The overall detection rate of hepatitis B markers was 83.2%; HBsAg was detected in 16.4% of all individuals. The high incidence of HBsAg in men (19.55%) compared to women (8.45%) was shown, the relative risk of HBV infection with the formation of HBsAg-positive chronic hepatitis B in males was also significantly higher. The prevalence of the HBV DNA in the study group was 30.4%, the OBI cases accounted for 15.6%. The prevalence of this form of the disease was shown in donors aged 30-49 years (24.78%), in the group of people younger than 30 years, the incidence was lower (8.73%), and at the age of over 50 years, OBI was not detected. Based on the phylogenetic analysis of 76 virus isolates, it was shown that genotype E prevails in the examined group (85.53%).Cases of pathogen DNA detection occurred in HBsAg-negative blood donors in the presence of anti-HBs IgG (n = 4), as well as in the simultaneous presence of ABs anti-HBs IgG and anti-HBc IgG (n = 7). The viral load exceeded 200 IU/ml in OBI samples. Escape mutations were detected by sequencing in each OBI sample, contributing to the virus escaping from diagnostic based on screening for HBsAg. Assessment of the prevalence viral hepatitis B markers in blood donors, determination of genotypes and clinically significant mutations of virus variants are necessary to ensure safe medical manipulations, control and prevention of the spread of this infectious agent.

Prevalence, incidence and residual risk of transfusion-transmitted hepatitis B virus infection in Italy from 2009 to 2018.

In Italy, the use of nucleic acid testing for hepatitis B virus (HBV) in donor screening has allowed the detection of infections in the window phase, as well as the presence of occult infections which could potentially be transmitted. The aim of this study was to analyse the trends of epidemiological data focused on HBV infection in blood donors and to estimate the residual risk of transmitting HBV from both the window phase and occult infection over a 10-year period in Italy. Data were obtained from the Italian Haemovigilance System which includes the results of screening tests for transfusion transmissible infections. During the period of this survey (2009-2018), the molecular methods used for HBV screening were transcription-mediated amplification and polymerase chain reaction tests. Prevalence and incidence were calculated. The residual risk was estimated by applying the incidence-window period model for acute cases and a more recently reported model for estimating the risk due to occult infections. A total of 17,424,535 blood donors and 30,842,794 donations were tested for HBV. Altogether, 6,250 donors tested positive for HBV markers: 4,782 (175.6×105) were first time donors and 1,468 (10.0×105) were repeat donors. The prevalence of HBV markers in first time donors was 275.9×105 in 2009, declining to 143.6×105 in 2018. The incidence of new infections was 3.37×105 in 2009 and 2.17×105 in 2018. The overall residual risk for HBV amounted to 1 in 2,566,854 donations calculated as the sum of risks of both acute infections in the window period (1 in 5,835,306 donations) and occult infections (1 in 4,582,270 blood units). In Italy, the residual risk of transfusing a blood unit infected with HBV, both from window phase and occult infections, is currently very low, amounting to levels that can be considered tolerable.

Prevalence of Hepatitis B Virus Infection in Blood Donors Based on Titer Hepatitis B Surface Antigen Examination (HBsAg)

Hepatitis B remains a global public health problem. Infection from hepatitis B virus (HBV) can be transmitted through a blood test or a blood transfusion. This study was conducted to identify the prevalence of HBV infection in blood donors based on examination of HBsAg titers . Blood donors from Tuban Red Cross used as sample. The method used in this research is HBsAg titers examination performed by ELISA according to the procedureoutlined in the Kit. HBsAg titers positive mostly found in men. In men from 13 samples (8.67%) are HBsAg titers positive of 150 samples while in woman all negative for HBsAg titers from 137 samples. The average titer positive was 3.095 with a standard deviation of 0.187. While HBsAg titers negative have average of 0.03 with a standard deviation of 0.14. This study showed that the prevalence of HBV infection in blood donors is most numerous in men with HBsAg titers positive number of 8.67%.

Prevalence of Hepatitis B Virus (HBV) Among Blood Donors in Eastern Saudi Arabia: Results From a Five-Year Retrospective Study of HBV Seromarkers.

BackgroundTransfusion-transmissible hepatitis B virus (HBV) infection is a major problem worldwide. Recently, confirmatory nucleic acid tests (NATs) for HBV DNA have been employed in several countries. We assessed the prevalence and yearly trends of HBV infection in blood donors in the Eastern Province of Saudi Arabia, screening for HBV surface antigen (HBsAg), antibody against HBV core antigen (anti-HBc), and HBV DNA.MethodsBetween 2011 and 2015, a total of 22,842 donors were screenedfor HBsAg, anti-HBc, and HBV DNA using the HBsAg Qualitative II kit (Abbott, Ireland Diagnostics Division, Sligo, Ireland), ARCHITECT Anti-hepatitis B core antigen antibody (HBc) II Assay kit (Abbott GmbH & Co. KG, Wiesbaden, Germany), and NAT Procleix Ultrio Elite Assay kit (Grifols Diagnostic Solutions Inc., Los Angeles, CA, USA), respectively.ResultsA total of 739 (3.24%) donors were HbsAg(+), anti-HBc(+), or HBV DNA(+); 63 (0.28%) were HbsAg(+), anti-HBc(+), and HBV DNA(+). Twelve (0.05%) were anti-HBc(+) and HBV DNA(+) but HBsAg(−); they were considered to have occult infection. Further, 664 (2.91%) were HBsAg(−) but anti-HBc(+), indicating chronic or resolving infection. HBV prevalence increased significantly from 2011 to 2012, increased marginally till 2013, and showed a decreasing trend from 2013 (P>0.05).ConclusionsThe five-year prevalence of HBV infection among blood donors in the Eastern Province of Saudi Arabia (3.24%) is lower than that reported for other regions in the country. The occult HBV infection rate of 0.05% emphasizes the importance of NATs in isolating potential infectious blood units.

Clinical impact of occult hepatitis B virus infection in immunosuppressed patients.

Occult hepatitis B infection (OBI), is characterized by low level hepatitis B virus (HBV) DNA in circulating blood and/or liver tissue. In clinical practice the presence of antibody to hepatitis B core antigen in hepatitis B surface antigen (HBsAg)-/anti-HBs-negative subjects is considered indicative of OBI. OBI is mostly observed in the window period of acute HBV infection in blood donors and in recipients of blood and blood products, in hepatitis C virus chronic carriers, in patients under pharmacological immunosuppression, and in those with immunodepression due to HIV infection or cancer. Reactivation of OBI mostly occurs in anti-HIV-positive subjects, in patients treated with immunosuppressive therapy in onco-hematological settings, in patients who undergo hematopoietic stem cell transplantation, in those treated with anti-CD20 or anti-CD52 monoclonal antibody, or anti-tumor necrosis factors antibody for rheumatological diseases, or chemotherapy for solid tumors. Under these conditions the mortality rate for hepatic failure or progression of the underlying disease due to discontinuation of specific treatment can reach 20%. For patients with OBI, prophylaxis with nucleot(s)ide analogues should be based on the HBV serological markers, the underlying diseases and the type of immunosuppressive treatment. Lamivudine prophylaxis is indicated in hemopoietic stem cell transplantation and in onco-hematological diseases when high dose corticosteroids and rituximab are used; monitoring may be indicated when rituximab-sparing schedules are used, but early treatment should be applied as soon as HBsAg becomes detectable. This review article presents an up-to-date evaluation of the current knowledge on OBI.

Occult hepatitis B virus infection as a cause of posttransfusion hepatitis in patients with cancers

Prevalence of hepatitis B virus (HBV) infection is increased in patients of cancer with increased mortality. Multiple transfusions of blood and blood-related products are a potential source. This study aims to assess the incidence of hepatitis B surface antigen (HBsAg) seroconversion in cancer patients receiving transfusion of blood or blood-related products and identify possible reasons for infection in these patients. Patients of cancer receiving blood products, who were HBsAg-, anti-hepatitis B core (HBc)-, and HBV DNA-negative prior to transfusion, were tested for HBsAg by ELISA at 6, 12, and 24 weeks after the last transfusion. Blood donors were screened for HBsAg by ELISA. Twenty of 3,600 (0.56 %) blood donors tested positive for HBsAg and were rejected. Nine of 150 (6 %) cancer patients became HBsAg-positive posttransfusion which included seven patients who presented with acute hepatitis B and other two patients who remained HBsAg-positive without hepatitis. In 6/9 (66.6 %) patients, HBsAg positivity was related to blood transfusion as their corresponding blood donors on retesting the stored samples were positive for anti-HBc antibody and HBV DNA. In other three patients, the cause of their HBsAg positivity could not be ascertained. Occult HBV infection in blood donors is a potential source of posttransfusion HBV infection in recipients. Anti-HBc antibody and HBV DNA should be tested in blood donors especially when blood is given to cancer patients receiving chemotherapy.

Nucleic Acid Testing to Detect HBV Infection in Blood Donors

The detection of hepatitis B virus (HBV) in blood donors is achieved by screening for hepatitis B surface antigen (HBsAg) and for antibodies against hepatitis B core antigen (anti-HBc). However, donors who are positive for HBV DNA are currently not identified during the window period before seroconversion. The current use of nucleic acid testing for detection of the human immunodeficiency virus (HIV) and hepatitis C virus (HCV) RNA and HBV DNA in a single triplex assay may provide additional safety. We performed nucleic acid testing on 3.7 million blood donations and further evaluated those that were HBV DNA-positive but negative for HBsAg and anti-HBc. We determined the serologic, biochemical, and molecular features of samples that were found to contain only HBV DNA and performed similar analyses of follow-up samples and samples from sexual partners of infected donors. Seronegative HIV and HCV-positive donors were also studied. We identified 9 donors who were positive for HBV DNA (1 in 410,540 donations), including 6 samples from donors who had received the HBV vaccine, in whom subclinical infection had developed and resolved. Of the HBV DNA-positive donors, 4 probably acquired HBV infection from a chronically infected sexual partner. Clinically significant liver injury developed in 2 unvaccinated donors. In 5 of the 6 vaccinated donors, a non-A genotype was identified as the dominant strain, whereas subgenotype A2 (represented in the HBV vaccine) was the dominant strain in unvaccinated donors. Of 75 reactive nucleic acid test results identified in seronegative blood donations, 26 (9 HBV, 15 HCV, and 2 HIV) were confirmed as positive. Triplex nucleic acid testing detected potentially infectious HBV, along with HIV and HCV, during the window period before seroconversion. HBV vaccination appeared to be protective, with a breakthrough subclinical infection occurring with non-A2 HBV subgenotypes and causing clinically inconsequential outcomes. (Funded by the American Red Cross and others.).

Lack of occult hepatitis B virus infection among blood donors with isolated hepatitis B core antibody living in an HBV low prevalence region of Iran

Background Occult hepatitis B virus (HBV) infection in blood donors is considered a potential threat for the safety of the blood supply, however conclusive studies on this issue are lacking. The aim of this study was to assess the occult HBV infection in blood donors with isolated hepatitis B core antibody (anti-HBc) living in the city of Arak, in the Central Province of Iran, as a low prevalence region for HBV. Methods A total of 531 voluntary blood donors in Arak, Iran were included in this study. Hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), anti-HBc, and hepatitis C antibody (anti-HCV) were tested in all subjects. The presence of HBV-DNA was determined quantitatively in plasma samples of cases with isolated anti-HBc (HBsAg-negative, anti-HBs-negative, and anti-HBc-positive) by real-time PCR using the artus HBV RG PCR kit on the Rotor-Gene 3000 real-time thermal cycler. Results Of 531 subjects enrolled in this study, 11 (2.1%, 95% confidence interval 0.8–3.2%) had isolated anti-HBc. HBV-DNA was not detected in any of the cases with isolated anti-HBc. Conclusions Our study showed that all the blood donors with isolated anti-HBc were negative for HBV-DNA, and occult HBV infection did not occur in the blood donors of this low prevalence region for HBV infection.

Acute Hepatitis B 14 Years after the Implementation of Universal Vaccination in Italy: Areas of Improvement and Emerging Challenges

Italy had intermediate-level endemicity for hepatitis B virus (HBV) infection in the 1970s and 1980s. In 1991, vaccination of infants and adolescents became mandatory. We report the impact of universal vaccination 14 years after its beginning. We performed a case-control study within a population-based surveillance for acute viral hepatitis. The incidence of acute hepatitis B (AHB) was estimated for the time since 1991, and the association between AHB and the considered risk factors was analyzed for the period 2001-2005. The incidence of AHB progressively decreased from 1991 to 2005, mainly for persons in the age groups targeted by the universal vaccination campaign: there was a 24-fold and 50-fold decrease in the 15-24-year and 0-14-year age groups, respectively; for the > or =25-year age group, the incidence halved. Owing to the persons' ages, approximately 3% of total AHB cases should have been the target of vaccination campaign. In 2004-2005, foreigners accounted for 14% of total cases and for 57% of persons who should have been targets for vaccination. Missed opportunities for immunization were documented for approximately 50% of patients with AHB who reported cohabitation with HBV carriers and for 70% of those who reported injection drug use. The strongest associations with AHB were found for blood transfusion (adjusted odds ratio [OR(adj)], 8.4; 95% confidence interval [CI], 2.7-26), cohabitation with HBV carriers (OR(adj), 5.3; 95% CI, 3.6-7.7), injection drug use (OR(adj), 3.8; 95% CI, 2.5-5.8), and unsafe sexual practices (OR(adj), 2.8; 95% CI, 1.9-4.2). Universal vaccination has contributed to a decreasing AHB incidence in Italy, especially by reducing the risk of infection among persons aged 15-24 years. Most infections occur in persons aged > or =25 years in association with injection drug use, unsafe sexual activity, percutaneous treatment, and iatrogenic exposure. Improvement of vaccine coverage in high-risk groups and adherence to infection control measures during surgery and percutaneous treatment are needed. The high risk still associated with blood transfusion needs to be further investigated, with consideration of occult HBV infection in blood donors. The potential spread of HBV infection from the immigrant population deserves adequate health policy prevention programs.

Effectiveness of DNA-recombinant anti-hepatitis B vaccines in blood donors: a cohort study

BackgroundAlthough various studies have demonstrated efficacy of DNA-recombinant anti-hepatitis B vaccines, their effectiveness in health care settings has not been researched adequately. This gap is particularly visible for blood donors, a group of significant importance in the reduction of transfusion-transmitted hepatitis B.MethodsThis is a double cohort study of 1411 repeat blood donors during the period 1998–2002, involving a vaccinated and an unvaccinated cohort, with matching of the two in terms of sex, age and residence. Average follow-up was 3.17 person-years. The outcome measure was infection with hepatitis B virus (HBV), defined by testing positive on serologic markers HBsAg or anti-HBC. All blood donors were from the blood bank in Joaçaba, federal state of Santa Catarina, Brazil.ResultsThe cohorts did not differ significantly regarding sex, age and marital status but the vaccinated cohort had higher mean number of blood donations and higher proportion of those residing in the county capital Joaçaba. Hepatitis B incidences per 1000 person-years were zero among vaccinated and 2,33 among non-vaccinated, resulting in 100% vaccine effectiveness with 95% confidence interval from 30,1% to 100%. The number of vaccinated persons necessary to avoid one HBV infection in blood donors was estimated at 429 with 95% confidence interval from 217 to 21422.ConclusionThe results showed very high effectiveness of DNA-recombinant anti-HBV vaccines in blood donors. Its considerable variation in this study is likely due to the limited follow-up and the influence of confounding factors normally balanced out in efficacy clinical trials.

P1450 Evaluation of real-time PCR based assays for the detection and quantitation of CMV DNA

Occult hepatitis B virus (HBV) infection in blood donors is considered a potential threat for the safety of the blood supply, however conclusive studies on this issue are lacking. The aim of this study was to assess the occult HBV infection in blood donors with isolated hepatitis B core antibody (anti-HBc) living in the city of Arak, in the Central Province of Iran, as a low prevalence region for HBV.A total of 531 voluntary blood donors in Arak, Iran were included in this study. Hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), anti-HBc, and hepatitis C antibody (anti-HCV) were tested in all subjects. The presence of HBV-DNA was determined quantitatively in plasma samples of cases with isolated anti-HBc (HBsAg-negative, anti-HBs-negative, and anti-HBc-positive) by real-time PCR using the artus HBV RG PCR kit on the Rotor-Gene 3000 real-time thermal cycler.Of 531 subjects enrolled in this study, 11 (2.1%, 95% confidence interval 0.8–3.2%) had isolated anti-HBc. HBV-DNA was not detected in any of the cases with isolated anti-HBc.Our study showed that all the blood donors with isolated anti-HBc were negative for HBV-DNA, and occult HBV infection did not occur in the blood donors of this low prevalence region for HBV infection.

Epidemiology of HBV infection in Asian blood donors: Emphasis on occult HBV infection and the role of NAT

Hepatitis B virus (HBV) infection is endemic in many Asian countries. Among many transmission routes, transfusion is the one that should be prevented. The first major success in enhancing transfusion safety came with the implementation of hepatitis B surface antigen (HBsAg) in the early 1970s. However, the studies quoted in this review demonstrate that transmission by blood components negative for HBsAg can still occur in the acute phase of infection during the seronegative window period, or during chronic stages of infeetion (i.c. “occult” HBV infection, OHB). OHB is defined as the presence of HBV DNA in blood or liver tissues in patients negative for HBsAg, with or without any HBV antibodies. Because of limitations in current blood screening practices, OHB is an overlooked source of HBV transmission. For policy development on screening for HBV infection in blood donors, it would be useful to assess the relative contribution of the above two sources of transfusion-transmitted HBV infection from HBsAg-negative donations. New screening policy should be evaluated on the basis of available data or newly designed studies. While anti-HBc screening can climinate residual risk of occult HBV transmission by transfusion in low-endemic areas, it would not be practical in most parts of the world where the prevalence of anti-HBc is >10% as too many otherwise healthy donors will be ineligible. On the contrary, studies mentioned in this paper indicate that nucleic acid amplification test (NAT) or new HBsAg tests of enhanced sensitivity would be effective in the screening of blood donors for OHB in highly endemic countries. However, the cost-effectiveness of blood screening tests is a major concern in Asia. We therefore have systemically reviewed the literature on prevalence and infectivity of OHB in Asian countries and the possible role of NAT for identifying blood donors in the pre-HBsAg window phase or in later stages of OHB.

The risk of hepatitis B virus infection by transfusion in Kumasi, Ghana

The risk of hepatitis B virus (HBV) transmission by transfusion in sub-Saharan Africa is considered to be relatively low, and testing of blood donors is often not done or is done relatively poorly. To re-examine this attitude, we identified HBV chronically infected blood donors from a major hospital in Ghana with a range of hepatitis B surface antigen (HBsAg) assays. Test efficacy was estimated using HBV DNA as a gold standard, and the risk of HBV infection in blood recipients was estimated for different testing strategies. Particle agglutination, dipstick, and enzyme immunoassay (EIA) HBsAg screening detected 54%, 71%, and 97% of HBV infectious donors, respectively. The risk of HBV transmission to recipients less than 10 years old ranged between 1:11 and 1:326 with blood unscreened and screened by EIA, respectively. For older recipients, the risk decreased a further 4-fold because of the high frequency of natural exposure to HBV. A total of 98% of HBsAg-confirmed positive samples contained HBV DNA. HBV DNA load was less than 1 x 10(4) IU/mL in 75% of HBsAg-reactive samples, most of them anti-HBe reactive. Approximately 0.5% of HBsAg-negative but anti-HBc-positive samples contained HBV DNA. The use of sensitive HBsAg tests is critical to prevent transfusion transmission of HBV infection to young children in a population with a 15% prevalence of chronic HBV infection in blood donors. However, this will not have much effect on the prevalence of this infection unless other strategies to protect children from infection are also advanced in parallel.

The Clinical Features of Chronic Hepatitis C Are Not Affected by the Coexistence of Hepatitis B Virus DNA in Patients Negative for Hepatitis B Surface Antigen

Hepatitis B virus (HBV) DNA has been detected in the sera of hepatitis patients who are negative for hepatitis B surface antigen (HBsAg) by polymerase chain reaction (PCR). The purpose of the present study was to clarify the clinical characteristics of patients with chronic hepatitis C who are negative for serum HBsAg and positive for HBV DNA. The subjects included 49 patients with chronic hepatitis C who were negative for serum HBsAg and 119 blood donors who served as healthy controls. Serum samples were tested for the presence of HBV DNA by the nested PCR method. Serum HBV DNA was detected in 18 (37.7%) of the 49 chronic hepatitis C patients and in none (0%) of the 119 blood donors. Among the hepatitis C patients, HBV DNA was detected in 20.7% of those who were negative for all HBV-associated markers and in 57.1% of those who were positive for one or more HBV-associated marker. The HBV DNA-positive rate among those in each F stage did not significantly differ. The liver function parameters of the HBV DNA-positive and the HBV DNA-negative chronic hepatitis C patients did not significantly differ. These results suggest that hepatitis C virus is frequently coinfected with serum HBsAg-negative HBV, and that the incidence of HBV infection in blood donors is low. However, it is considered that HBsAg-negative HBV infection does not modify the blood biochemical features of chronic hepatitis C.