Hepatitis B virus prevalence in first-time blood donors in Flanders, Belgium: Impact of universal vaccination and migration

Prevalence and Trends of Transfusion-Transmissible HBV Infection Among Blood Donors in Southwestern China: A Six-Year Retrospective Study

Objective

Hepatitis B virus (HBV) infection is a significant global public health concern, with variable prevalence rates across regions. The prevalence of transfusion-transmitted HBV infection (TT-HBV) via donated blood necessitates an evaluation of blood safety and potential risks to the population. This study assessed the prevalence of HBV infection among blood donors in Southwestern China over 6 years.

Methods

We analyzed 903,023 blood donations from a central blood center in Southwestern China between January 2017 and December 2022. The prevalence of HBV in donations was determined for one-time and repeat donors, considering birth cohorts and covariates. Demographic characteristics, donation frequency, and anti-HBV antibody status were analyzed to estimate the incidence of TT-HBV.

Results

One-time donors provided 47.78% of the samples, and 52.22% were from repeat donors. The HBV prevalence decreased from 1.0% in 2017 to 0.87% in 2022 in one-time donors and from 0.30% to 0.09%, respectively, in repeat donors. A significantly lower HBV prevalence was identified in the post-1992 birth cohort (0.33%) than in the pre-1992 birth cohort (1.67%). The estimated incidences of TT-HBV occurring from one-time donors, repeat donors, post-1992 birth cohort donors, and pre-1992 birth cohort donors were 20.76, 13.84, 0.82, and 20.98 per 104 person-years, respectively.

Conclusion

Our findings indicate a decreasing trend in HBV prevalence among blood donors in Southwestern China over the 6-year study period. This decline may be attributed to the widespread administration of HBV vaccinations and stringent screening measures implemented by blood donation centers. Continuous monitoring for HBV among blood donors is necessary to evaluate the effectiveness of preventive measures and inform future strategies to reduce transmission.

Analysis of hepatitis B Virus Test results among blood donors in Chongqing, China

BACKGROUND

Hepatitis B virus (HBV) infection is a major concern regarding blood safety in countries with a high HBV prevalence, such as China. We aimed to understand the prevalence of HBV infection among blood donors in Chongqing and provide an important basis for developing appropriate blood screening strategies.

METHODS

Dual enzyme-linked immunosorbent assays (ELISAs) for hepatitis B surface antigen (HBsAg) were conducted in parallel with nucleic acid testing (NAT) of donors. All HBsAg-reactive and/or HBV DNA-positive blood samples were tested for HBsAg and hepatitis B DNA levels.

RESULTS

A total of 117,927 blood donor samples were collected from the Chongqing Blood Center between April 2020 and November 2020. In total, 473 HBV-ineligible samples were retained for HBsAg and DNA confirmation. A total of 272 samples were confirmed to be HBsAg+, including 2 HBV DNA - and 270 HBV DNA + samples. A total of 201 donations were HBsAg-, including 72 HBV DNA - samples. The rate of HBV infection was 65.33% (309/473) in men, which was significantly higher than that in women (p < 0.001). The HBV failure rate was higher among the first-time donors (p < 0.05). Of the 182 NAT R/HBsAg N/N samples (Nucleic acid test reactivity/2 anti-HBsAg tests negative), 37.91% (69/182) were false positives. The proportion of hepatitis B infections in the 18 NAT R/HBsAg N/R (Nucleic acid test reactivity/1 anti-HBsAg tests negative) samples was 94.44% (17/18), of which 50% (9/18) were occult HBV infection. A total of 95.83% (69/72) of the false positives were from the NAT R/HBsAg N/N group, and 58.33% (42/72) were first-time donors.

CONCLUSION

Our data showed a strikingly high HBV infection rate among blood donors in Chongqing. Double ELISA and single NAT can effectively prevent HBV leakage and improve blood safety. First-time donors have a high rate of HBV transplant failure; therefore, donors should be retained and recruited from low-risk groups.

SARS-CoV-2 vaccination in Canadian blood donors: Insight into donor representativeness of the general population

Introduction

Blood donors world-wide were indispensable for monitoring anti-SARS-CoV-2 antibodies generated by infection and vaccination during the pandemic. Prior to the pandemic, donor vaccination behaviours were under-studied. We aimed to compare the percentage of Canadian blood donors with SARS-CoV-2 vaccination antibodies with the percentage of the general population who received at least one dose of vaccine each month during initial vaccine deployment. We also report donor attitudes towards SARS-CoV-2 vaccination.

Methods

Canadian blood donors were randomly selected for SARS-CoV-2 antibody testing over 2021 (N = 165,240). The percentage of donor samples with vaccination antibodies were compared with the percentage of general population who received at least one dose of vaccine in each month of 2021 except February. A random sample of Canadian blood donors were surveyed about vaccination intent and attitudes (N = 4,558 participated, 30.4 % response rate).

Results

The percentages of the general population vaccinated and donors with vaccination antibodies increased from 1 % to over 90 %. General population vaccination was greater early in vaccine deployment than donors (p < 0.05), greater in donors than the general population by mid-2021 (p < 0.05) but they were similar by the end of 2021. While 52.6 % of surveyed donors had received vaccine in May 2021, a further 41.1 % intended to when eligible. Most donors thought COVID-19 infection could be serious (83.5 %) and that it was important to be vaccinated even if previously infected (77.8 %).

Conclusion

Early pandemic vaccine prioritization to at-risk individuals and healthcare workers gave rise to higher general population vaccination percentages, while donors had higher vaccine antibody percentages as vaccine was deployed to progressively younger age groups. Since blood donors may be more willing to receive vaccination, under pandemic conditions they may be valuable for monitoring vaccination-induced seroprevalence.

Hepatitis B Blood Donor Screening Data: An Under-Recognized Resource for Canadian Public Health Surveillance

Hepatitis B surveillance is essential to achieving Canada's goal of eliminating hepatitis B by 2030. Hepatitis B rates, association of infection with vaccine age-eligibility, and risk factors were analyzed among 1,401,603 first-time Canadian blood donors from 2005 to 2020. Donors were classified as having likely chronic or likely resolved/occult infections based on hepatitis B surface antigen, anti-hepatitis B core antigen, and hepatitis B nucleic acid test results. Likely chronically infected and control donors (ratio 1:4) participated in risk-factor interviews. The 2019 rate of likely chronic infection was 61.9 per 100,000 (95% CI 46.5-80.86) and 1449.5 per 100,000 for likely resolved/occult infections (95% CI 1370.7-1531.7). Likely chronic infections were higher in males (OR 3.2; 95% CI 2.7-3.7) and the vaccine-ineligible birth cohort (OR 1.9; 95% CI 1.6-2.2). The main risk factors were living with someone who had hepatitis (OR 12.5; 95% CI 5.2-30.0) and ethnic origin from a high-prevalence country (OR 8.4; 95% CI 5.9-11.9). Undiagnosed chronic hepatitis B may be more prevalent in Canada than currently determined by traditional passive hepatitis B reporting. Blood donor data can be useful in informing hepatitis B rates and evaluating vaccination programs in Canada.

Prevalence of Occult Hepatitis B Virus Infection in Blood Donors with Negative ID-NAT in Switzerland

Introduction

Screening of hepatitis B surface antigen (HBsAg) and individual-donation nucleic acid amplification testing (ID-NAT) of blood donors have become standard to detect hepatitis B virus (HBV) infection. However, there is still a residual risk of HBV transmission by blood components of donors suffering from occult HBV infection (OBI). Therefore, many countries implemented universal testing of anti-HBV core antigen (anti-HBc) antibodies in order to increase blood safety. In Switzerland, anti-HBc testing is not part of the routine blood donor-screening repertoire. Therefore, we sought to assess prevalence of donors with OBI in a Swiss blood donor collective.

Methods

Blood donations were prospectively investigated for the presence of anti-HBc antibodies during two time periods (I: all donors, March 2017; II: first-time donors only, April 2017 until February 2018). Anti-HBc-positive findings were confirmed by an anti-HBc neutralization test. Discarded plasma samples of anti-HBc-confirmed positive donors were ultracentrifuged and subsequently retested by regular HBV-ID-NAT to search for traces of HBV.

Results

During time period I, 78 (1.6%) individuals out of 4,923 donors were confirmed anti-HBc-positive. Sixty-nine (88%) anti-HBc-positive samples were available and processed by ultracentrifugation followed by repeat HBV-ID-NAT. Four samples (5.8%) were found positive for HBV DNA. Sixty-five (94.2%) samples remained HBV NAT-negative upon ultracentrifugation. During time period II, 56 (0.9%) donor samples out of 6,509 exhibited anti-HBc-confirmed positive. Fifty-five (98%) samples could be reassessed by HBV-ID-NAT upon ultracentrifugation. Three (5.5%) samples contained HBV DNA and 52 (94.5%) samples remained HBV NAT-negative.

Conclusion

Overall, we detected 7 viremic OBI carriers among 11,432 blood donors, which tested negative for HBV by standard HBV-ID-NAT and HBsAg screening. In contrast, OBI carriers showed positive anti-HBc findings which could be confirmed in 83.8% of the cases. Thus, OBI might be missed by the current HBV screening process of Swiss blood donors. We suggest to review current HBV screening algorithm. Extended donor screening by anti-HBc testing may unmask OBI carriers and contribute to blood safety for the recipient of blood products.

Prevalence and Association of Transfusion Transmitted Infections with ABO and Rh Blood Groups among Blood Donors in the Western Region of Saudi Arabia: A 7-Year Retrospective Analysis

This study was aimed at determining the prevalence estimate and association of transfusion-transmitted infections (TTIs) with ABO and Rh blood groups among blood donors at the King Faisal Specialist Hospital and Research Center (KFSH & RC) in the western region of Saudi Arabia. A retrospective study was conducted at the blood bank center of KFSH and RC from 1 January 2013 to 31 December 2019. Data on ABO and Rh blood group testing, serological testing, molecular investigations, serological assays, nucleic acid testing (NATs), and socio-demographic information were gathered. During the study period, there were 959,431 blood donors at the KFSH and RC. The overall 7-year cumulative prevalence estimate of blood transfusion-transmitted infections among blood donors was low at 7.93%, with an average prevalence estimate of 0.66%. Donors with the O blood group, the O RhD +ve blood group, in particular, were more at risk of developing TTIs, whereas donors with the AB blood group, the AB RhD −ve blood group, in particular, were at the lowest risk of developing TTIs. In total, 96.9% of the blood donors were males (n = 916,567). Almost half of the blood donors belong to the O blood group (49.4%). A total of 861,279 (91.0%) donors were found to be RhD positive. The percentages of TTIs were found to be higher in RhD +ve donors compared with RhD −ve donors. The prevalence estimate of the hemoglobin C (HbC) infection was the most common TTI among the blood donors being 3.97%, followed by malaria being 2.21%. The least prevalence estimate of TTI in the present study was for NAT HIV being 0.02%. Significant associations were observed between RhD +ve and RhD −ve among the malaria-infected donors (A: χ2 = 26.618, p = 0.001; AB: χ2 = 23.540, p = 0.001; B: χ2 = 5.419, p = 0.020; O: χ2 = 68.701, p = 0.001). The current 7-year retrospective study showed a low level of TTIs among blood donors. However, we urge that more research encompassing the entire country be conducted in order to obtain more representative results in terms of the prevalence estimate and association of transfusion-transmitted infections with ABO and Rh blood groups in communities.