Comparison of donor and general population demographics over time: a BEST Collaborative group study

Increasing the upper age limit for blood donation: Perspectives from older donors

BACKGROUND AND OBJECTIVES

In the Netherlands, as of April 2018, the upper age limit for blood donation has been raised from 69 to 79 years, providing an opportunity to study older donors' perspectives regarding donating at older age. This study aims to explore whether older donors agree with the increase of the age limit, if they feel obliged to continue donating, to identify their motivators and barriers for donating blood and describe donation-related experiences and complications.

MATERIALS AND METHODS

An online survey was distributed among Dutch blood donors aged 68-73 years. The survey contained questions regarding the increase of the upper age limit, motivations and barriers for donating, donation-related experiences and obligatory feelings to continue donating.

RESULTS

Six hundred sixty donors (55%) were included in the analyses, including 38 stopped donors. Most donors (92%) agreed with the increase of the upper age limit. Approximately 63% of participating donors felt obliged to continue donating, especially women with high education. Donors indicated they felt healthy enough to keep donating (95%), and 72% thought it is good for their health to keep donating. Few donors reported that they found it hard to keep donating (5%) or indicated that they did not feel healthy enough to donate or thought it was not safe for them anymore (3.4%).

CONCLUSION

Most of the older donors agree with the increase of the upper age limit for blood donation, report only few and minor donation-related experiences or complications and are highly motivated to continue their donor career at an older age.

The Impact of Age Group in Hierarchical Forecasting of Monthly Blood Donations in Zimbabwe

Background

To meet the blood requirements for transfusion therapy, blood banks need to ensure that blood inventories are maintained at desirable levels. There is a rising global need for optimal ways to manage blood supply and demand using statistical models in blood inventory planning and management. Thus, blood donation forecasting using donor-specific characteristics such as donor type and age is critical in managing the blood bank inventory.

Methods

The monthly blood donation data covering the period 2007 to 2018, collected from the National Blood Service Zimbabwe (NBSZ) was used in this study. The data is first disaggregated based on donor age, and further disaggregation is performed for each age group based on donor type. The hierarchical forecasting approaches, namely the bottom-up, top-down and the optimal combination methods were used in the data analysis. The Error-Trend-Seasonality (ETS) and Autoregressive Integrated Moving Average (ARIMA) methods are used in the hierarchical forecasting approaches to generate the forecasts.

Results

New blood donors account for more than 55% of blood donations in Zimbabwe. The younger donors (16-29 years) dominate the blood donations, accounting for 89.2% of the donations. Young and new donors account for nearly 50% of the donations. The middle-aged and older donors have lower blood donations. The bottom-up approach under the ARIMA model outperformed all the other approaches. The future projections show that new and young donors will increase in blood donations, regular donations will decline slightly while the occasional donations are projected to remain constant.

Conclusion

Hierarchical forecasting is a unique approach in that the different aggregation levels reveal important features of the blood donation data. The lower percentage of regular donations is worrisome to blood authorities as it points to new blood donors not returning for further donations. Blood authorities need to develop policies that will encourage new and young donor categories to become regular donors.

Systematic review of seroprevalence of SARS-CoV-2 antibodies and appraisal of evidence, prior to the widespread introduction of vaccine programmes in the WHO European Region, January-December 2020

OBJECTIVES

Systematic review of SARS-CoV-2 seroprevalence studies undertaken in the WHO European Region to measure pre-existing and cumulative seropositivity prior to the roll out of vaccination programmes.

DESIGN

A systematic review of the literature.

DATA SOURCES

We searched MEDLINE, EMBASE and the preprint servers MedRxiv and BioRxiv in the WHO 'COVID-19 Global literature on coronavirus disease' database using a predefined search strategy. Articles were supplemented with unpublished WHO-supported Unity-aligned seroprevalence studies and other studies reported directly to WHO Regional Office for Europe and European Centre for Disease Prevention and Control.

ELIGIBILITY CRITERIA

Studies published before the widespread implementation of COVID-19 vaccination programmes in January 2021 among the general population and blood donors, at national and regional levels.

DATA EXTRACTION AND SYNTHESIS

At least two independent researchers extracted the eligible studies; a third researcher resolved any disagreements. Study risk of bias was assessed using a quality scoring system based on sample size, sampling and testing methodologies.

RESULTS

In total, 111 studies from 26 countries published or conducted between 1 January 2020 and 31 December 2020 across the WHO European Region were included. A significant heterogeneity in implementation was noted across the studies, with a paucity of studies from the east of the Region. Sixty-four (58%) studies were assessed to be of medium to high risk of bias. Overall, SARS-CoV-2 seropositivity prior to widespread community circulation was very low. National seroprevalence estimates after circulation started ranged from 0% to 51.3% (median 2.2% (IQR 0.7-5.2%); n=124), while subnational estimates ranged from 0% to 52% (median 5.8% (IQR 2.3%-12%); n=101), with the highest estimates in areas following widespread local transmission.

CONCLUSIONS

The low levels of SARS-CoV-2 antibody in most populations prior to the start of vaccine programmes underlines the critical importance of targeted vaccination of priority groups at risk of severe disease, while maintaining reduced levels of transmission to minimise population morbidity and mortality.

Supplemental findings of the 2021 National Blood Collection and Utilization Survey

BACKGROUND

The Department of Health and Human Services' National Blood Collection and Utilization Survey (NBCUS) has been conducted biennially since 1997. Data are used to estimate national blood collection and use. Supplemental data from the 2021 NBCUS not presented elsewhere are presented here.

METHODS

Data on survey participation, donor characteristics, blood component cost, transfusion-associated adverse reactions, and implementation of blood safety measures, including pathogen-reduction of platelets, during 2021, were analyzed. Comparisons are made to 2019 survey data where available (2013-2019 for survey participation).

RESULTS

During 2021, there were 11,507,000 successful blood donations in the United States, a 4.8% increase from 2019. Persons aged 45-64 years accounted for 42% of all successful blood donations. Donations by persons aged 65 years and older increased by 40.7%, while donations among minorities and donors aged <25 years decreased. From 2019 to 2021, the median price hospitals paid per unit of leukoreduced red blood cells, leukoreduced and pathogen-reduced apheresis platelets, and fresh frozen plasma increased. The largest increase in price per unit of blood component in 2021 was for leukoreduced apheresis platelets, which increased by ~$51. Between 2019 and 2021, the proportion of transfusing facilities reporting use of pathogen-reduced platelets increased, from 13% to 60%. Transfusion-related adverse reactions declined slightly between 2019 and 2021, although the rate of transfusion-transmitted bacterial infections remained unchanged.

CONCLUSION

During 2021, blood donations increased nationally, although donations from those aged <25 years and minorities declined. The prices hospitals paid for most blood products increased, as did the use of pathogen-reduced platelets.

Young apheresis platelet donors show significant and sustained growth over the last decade in the US, 2010-2019: A favorable sign of the resiliency of the platelet supply

BACKGROUND

Platelet demand continues to rise and US hospitals frequently face shortages. The peak median age of apheresis platelet donors (APD) is believed to have increased over the last decade, raising concerns that the APD base is not being adequately replenished with young donors.

STUDY DESIGN/METHODS

American Red Cross (ARC) apheresis platelet collections were evaluated from calendar years 2010 through 2019. APD, products per procedure/split rate (PPP) and donation frequencies were stratified into age groups.

RESULTS/FINDINGS

The number of unique APD from calendar year 2010 through 2019 in the ARC donor pool increased from 87,573 to 115,372 donors, representing a 31.7% overall growth. Donors in the 16-40 year-old (y) age group increased by 78.8% overall, with the largest absolute increases seen in the 26-30 y (4852 donors, 99.9% growth), followed by the 31-35 y (3991, 94.1%) group. Donors aged 56+ increased by 50.4% overall, with the largest increase seen in the 66-70 y (5988 donors, 108.1% growth) group. Middle-aged donors, aged 41-55 y, demonstrated a decrease of 16.5%. Over the last decade, the youngest age groups (16-40 y) comprised 61.3% of first-time donors (FTD). Annual donation frequency increased with increasing age and PPP. The highest donation frequencies were seen in the oldest age groups.

CONCLUSION

Although the peak median age of APD increased over the study period, relative contribution of the 16-40 y APD base also increased. Older donors exhibited the highest donation frequencies and thus contributed the largest volume of apheresis platelet units. Platelet donor activity declined in the middle age (41-55 y) group.

Evolving policies for donors with diabetes: The Canadian experience

BACKGROUND AND OBJECTIVES

Donor criteria for diabetes vary significantly. We describe our evolving policies for donors with diabetes, their contribution to the Canadian blood supply and their rate of syncopal reactions compared to other donors.

MATERIALS AND METHODS

All donors are asked if they have diabetes and have taken medications in the last 3 days. We assessed donors with diabetes on various medications, the number deferred over time, and syncopal reactions in donors with diabetes and other donors in our donor reaction database.

RESULTS

Policy changes allowing type 2 diabetic donors on oral hypoglycaemics alone, type 2 diabetic donors on oral medications and insulin and type 1 diabetic donors (all on insulin) to donate resulted in a decrease in deferrals from 450 to 22 donors annually. Of donors being treated with medication for diabetes, 11% are receiving insulin as part of their treatment. Syncopal reaction rates were low and not statistically different between diabetic and non-diabetic donors, although confidence intervals (CIs) are large.

CONCLUSION

Policies decreased deferrals while maintaining safety. A longer observation period would strengthen these observations.

How do we decide how representative our donors are for public health surveillance?

BACKGROUND

Surveillance of blood donors is fundamental to safety of the blood supply. Such data can also be useful for public health policy but tend to be underutilized. When the COVID-19 pandemic arrived, blood centers around the world measured blood donor SARS-CoV-2 seroprevalence to inform public health policy. There is now a movement toward blood centers becoming more involved in public health research and surveillance post-pandemic. However, blood donors are a healthy population and not representative of all segments of the general population. In this article, we explain how blood centers can evaluate their donor base to understand which part of the general population they are representative of.

STUDY DESIGN AND METHODS

Methodologic approaches for evaluating samples relative to the target population were reviewed. Blood donor data that are available to most blood centers were identified and application to assess representativeness of blood donors was evaluated.

RESULTS

Key aspects of blood donor data to compare with general population data include donor selection criteria, health indicators, geography, and demographics. In some cases, statistical adjustment can improve representativeness.

DISCUSSION

Comparing key blood donor data with corresponding general population data can define the subset of the general population for which a particular blood center's donors may be representative of. We suggest that donors are an ideal convenience population for surveillance of infectious agents which are frequently asymptomatic and main routes of transmission are not deferrable, for studying the natural history of disease in an initially well population, and for vaccination serology surveillance.

Frequency and Geographic Distribution of Borrelia miyamotoi, Borrelia burgdorferi, and Babesia microti Infections in New England Residents

BACKGROUND

Borrelia miyamotoi is a relapsing fever spirochete that relatively recently has been reported to infect humans. It causes an acute undifferentiated febrile illness that can include meningoencephalitis and relapsing fever. Like Borrelia burgdorferi, it is transmitted by Ixodes scapularis ticks in the northeastern United States and by Ixodes pacificus ticks in the western United States. Despite reports of clinical cases from North America, Europe, and Asia, the prevalence, geographic range, and pattern of expansion of human B. miyamotoi infection are uncertain. To better understand these characteristics of B. miyamotoi in relation to other tickborne infections, we carried out a cross-sectional seroprevalence study across New England that surveyed B. miyamotoi, B. burgdorferi, and Babesia microti infections.

METHODS

We measured specific antibodies against B. miyamotoi, B. burgdorferi, and B. microti among individuals living in 5 New England states in 2018.

RESULTS

Analysis of 1153 serum samples collected at 11 catchment sites showed that the average seroprevalence for B. miyamotoi was 2.8% (range, 0.6%-5.2%), which was less than that of B. burgdorferi (11.0%; range, 6.8%-15.6%) and B. microti (10.0%; range, 6.5%-13.6%). Antibody screening within county residence in New England showed varying levels of seroprevalence for these pathogens but did not reveal a vectoral geographical pattern of distribution.

CONCLUSIONS

Human infections caused by B. miyamotoi, B. burgdorferi, and B. microti are widespread with varying prevalence throughout New England.

Who donates? Patterns of blood donation and donor characteristics at a university-affiliated hospital-based donor center

BACKGROUND

Blood donors are a crucial element of the blood supply chain. Optimal recruitment strategies built upon the robust understanding of local donor behavior and demographics-specifically, the donor characteristics of our university-affiliated hospital-based donor center-improve outreach and retention of donors.

STUDY DESIGN AND METHODS

This retrospective study analyzed blood donors' genders, ethnicities, and donation frequencies at a university-affiliated hospital-based donor center from 2014-2019, stratified into seven age cohorts. Donor ethnicity demographics were compared to the reported student, employee, and LA County population.

RESULTS

Female donors outnumbered male donors in all age cohorts. The majority of donors self-identified (SI) as White (36.7%), Hispanic/Latino (21.6%), or Asian (19.1%). Older donors (age > 25) donated more frequently (4.1 vs. 2.3 donations per donor) than younger donors (age ≤ 25). Repeat donors who donated in multiple years during the study period were more likely to donate multiple times each year than those donors who only donated during 1 year.

DISCUSSION

Our donor demographics more closely reflect the university student and employee demographics than LA County demographics, demonstrating the broad local efforts of recruitment by student groups and donor center recruitment staff. However, non-White populations continue to be underrepresented. The majority of donors only donated once during the study period. Recruitment strategies to increase donor engagement among underrepresented populations and increase the proportion of repeat donors are likely to prove most beneficial.

Risk of HBV infection among male and female first-time blood donors born before and after the July 1986 HBV vaccination program in Taiwan

Background

In July 1984, Taiwan officially began a nationwide hepatitis B virus (HBV) vaccination program where only infants born to HBsAg-positive mothers were vaccinated free of charge until June 1986. However, from July 1986, all infants were vaccinated against HBV. The impact of the July 1986 HBV vaccination program on first-time blood donors has not been exhaustively studied. We, therefore, determined the risk of HBV among male and female first-time blood donors born before and after the July 1986 HBV vaccination program in Taiwan.

Methods

Initially, we recruited 857,310 first-time blood donors whose data were collected between 2013 and 2018 from 5 blood donation centers in Taiwan. However, we excluded donors with incomplete and outlying data (n = 12,213) and those born between July 1984 and June 1986 (n = 21,054). The final study participants comprised 9118 HBV positive and 814,925 HBV negative individuals. We divided the participants into two birth cohorts (born before and after July 1986) and assumed that those born before July 1986 were not vaccinated at birth while those born after July 1986 were vaccinated.

Results

The prevalence of HBV among those born before and after July 1986 was 4.53 and 0.25%, respectively. Individuals born after July 1986 had a lower risk of HBV than those born before July 1986. The adjusted odds ratio (OR), 95% confidence interval (CI) was 0.16, 0.13–0.19. Men had a higher risk of HBV than women (OR = 1.40, 95% CI = 1.34–1.47). The interaction between sex and birth date was significant (p-value = 0.0067). Stratification of participants by birth date revealed a higher risk of HBV in men compared to women in both birth cohorts. The OR, 95% CI was 1.47, 1.40–1.55 for those born before July 1986 but declined to 1.15, 1.02–1.29 for those born after July 1986.

Conclusions

The risk of HBV was lower among those born after than those born before the July 1986 vaccination program. In both cohorts, the risk was high in men relative to women. The seemingly protective effect among those born after July 1986 was higher in women than men.

Supplemental findings of the 2019 National Blood Collection and Utilization Survey

INTRODUCTION

Supplemental data from the 2019 National Blood Collection and Utilization Survey (NBCUS) are presented and include findings on donor characteristics, autologous and directed donations and transfusions, platelets (PLTs), plasma and granulocyte transfusions, pediatric transfusions, transfusion-associated adverse events, cost of blood units, hospital policies and practices, and implementation of blood safety measures, including pathogen reduction technology (PRT).

METHODS

National estimates were produced using weighting and imputation methods for a number of donors, donations, donor deferrals, autologous and directed donations and transfusions, PLT and plasma collections and transfusions, a number of crossmatch procedures, a number of units irradiated and leukoreduced, pediatric transfusions, and transfusion-associated adverse events.

RESULTS

Between 2017 and 2019, there was a slight decrease in successful donations by 1.1%. Donations by persons aged 16-18 decreased by 10.1% while donations among donors >65 years increased by 10.5%. From 2017 to 2019, the median price paid for blood components by hospitals for leukoreduced red blood cell units, leukoreduced apheresis PLT units, and for fresh frozen plasma units continued to decrease. The rate of life-threatening transfusion-related adverse reactions continued to decrease. Most whole blood/red blood cell units (97%) and PLT units (97%) were leukoreduced.

CONCLUSION

Blood donations decreased between 2017 and 2019. Donations from younger donors continued to decline while donations among older donors have steadily increased. Prices paid for blood products by hospitals decreased. Implementation of PRT among blood centers and hospitals is slowly expanding.

Global seroprevalence of SARS-CoV-2 antibodies: A systematic review and meta-analysis

BACKGROUND

Many studies report the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies. We aimed to synthesize seroprevalence data to better estimate the level and distribution of SARS-CoV-2 infection, identify high-risk groups, and inform public health decision making.

METHODS

In this systematic review and meta-analysis, we searched publication databases, preprint servers, and grey literature sources for seroepidemiological study reports, from January 1, 2020 to December 31, 2020. We included studies that reported a sample size, study date, location, and seroprevalence estimate. We corrected estimates for imperfect test accuracy with Bayesian measurement error models, conducted meta-analysis to identify demographic differences in the prevalence of SARS-CoV-2 antibodies, and meta-regression to identify study-level factors associated with seroprevalence. We compared region-specific seroprevalence data to confirmed cumulative incidence. PROSPERO: CRD42020183634.

RESULTS

We identified 968 seroprevalence studies including 9.3 million participants in 74 countries. There were 472 studies (49%) at low or moderate risk of bias. Seroprevalence was low in the general population (median 4.5%, IQR 2.4-8.4%); however, it varied widely in specific populations from low (0.6% perinatal) to high (59% persons in assisted living and long-term care facilities). Median seroprevalence also varied by Global Burden of Disease region, from 0.6% in Southeast Asia, East Asia and Oceania to 19.5% in Sub-Saharan Africa (p<0.001). National studies had lower seroprevalence estimates than regional and local studies (p<0.001). Compared to Caucasian persons, Black persons (prevalence ratio [RR] 3.37, 95% CI 2.64-4.29), Asian persons (RR 2.47, 95% CI 1.96-3.11), Indigenous persons (RR 5.47, 95% CI 1.01-32.6), and multi-racial persons (RR 1.89, 95% CI 1.60-2.24) were more likely to be seropositive. Seroprevalence was higher among people ages 18-64 compared to 65 and over (RR 1.27, 95% CI 1.11-1.45). Health care workers in contact with infected persons had a 2.10 times (95% CI 1.28-3.44) higher risk compared to health care workers without known contact. There was no difference in seroprevalence between sex groups. Seroprevalence estimates from national studies were a median 18.1 times (IQR 5.9-38.7) higher than the corresponding SARS-CoV-2 cumulative incidence, but there was large variation between Global Burden of Disease regions from 6.7 in South Asia to 602.5 in Sub-Saharan Africa. Notable methodological limitations of serosurveys included absent reporting of test information, no statistical correction for demographics or test sensitivity and specificity, use of non-probability sampling and use of non-representative sample frames.

DISCUSSION

Most of the population remains susceptible to SARS-CoV-2 infection. Public health measures must be improved to protect disproportionately affected groups, including racial and ethnic minorities, until vaccine-derived herd immunity is achieved. Improvements in serosurvey design and reporting are needed for ongoing monitoring of infection prevalence and the pandemic response.

Buffy coat platelets coming to America: Are we ready?

BACKGROUND

Buffy coat (BC) platelets (PLTs) have been used globally for many years. In 2004 Canadian Blood Services (CBS) made the decision to transition from PLT-rich plasma (PRP) to BC PLTs. We reviewed the benefits and manufacture process of BC and the implementation challenges involved.

STUDY DESIGN AND METHODS

A literature review was performed in the following areas: BC efficacy, donor population shifts, production and good stewardship of PLTs, logistic considerations with overnight holds, advantages of the overnight hold, the CBS experience, licensure and standards, and changes needed to produce BC PLTs in the United States. The aim was to analyze current practice and identify possible actions for blood centers and hospitals.

RESULTS

Implementation of BC would offer an additional source of PLTs to address the growing elderly population and the declining apheresis donor base. Substantial logistic, operational, and financial benefits were seen when CBS transitioned to BC with overnight hold.

CONCLUSIONS

Buffy coat blood products are widely used throughout the world. Recent conversion from PRP to BC by CBS showed that conversion can be accomplished with planning, communication, and partnership from all stakeholders. In conclusion, BC PLTs are worth serious consideration in the United States, but regulatory barriers in the United States will need to be addressed.

The current state of the platelet supply in the US and proposed options to decrease the risk of critical shortages

Due to circumstances such as increased demand and an aging donor pool, the likelihood of critical platelet shortages is increasing. The platelet supply could be improved through the expansion of the donor pool, the identification and sustained utilization of high-quality donors, and changes in component processing and storage that result in a longer platelet shelf-life. Refrigerated platelets, stored at 1° to 6°C, have the potential to improve patient safety by decreasing the risk of bacterial contamination while concurrently allowing for a longer storage period (eg, 14 days) and improved hemostatic effectiveness in actively bleeding patients. An approach utilizing remuneration of apheresis platelet donors combined with pathogen reduction of the platelet components could be used as a means to increase the donor pool and identify and sustain safe, reliable, high-quality donors. Remuneration might provide an incentive for underutilized populations (eg, individuals <30 years old) to enter the apheresis platelet donor population resulting in a significant expansion of the platelet donor pool. Over time, approaches such as the use of refrigerated platelets, platelet donor remuneration, and the application of pathogen reduction technology, might serve to attract a large, reliable, and safe donor base that provides platelet collections with high yields, longer shelf-lives and, excellent hemostatic function.

Demographical Pattern of Blood Donors and Pre-Donation Deferral Causes in Dhahran, Saudi Arabia

Background

Understanding the demographic features of blood donors is important for identifying the donor structure and guiding the recruitment and retention strategies of donors. This study was aimed to determine the demographic characteristics of blood donors, the types of donation drives, and the frequency and reasons for pre-donation deferral in our population.

Methods

This cross-sectional study included data analysis of all prospective blood donors presenting themselves for donation at the Blood Bank of the King Fahad Military Medical Complex, Dhahran, Saudi Arabia between January 2010 and December 2018. Eligibility of blood donation was assessed using a standardized history questionnaire, physical examination, hemoglobin estimation, pulse rate, blood pressure, and temperature. The questionnaire included the demographic features of the donor such as age, gender, and the reason for donation and other specific risk factors that potentially affect the safety of the donor or the recipient. Data analyzed using the analysis of SPSS version 20 (SPSS Inc., Chicago, IL, USA) were used to calculate the unadjusted odds ratios (OR) and the respective 95% confidence interval for the association between the various demographic parameters.

Results

A total of 28,189 potential donations were recorded during the study period; of these, 77.4% were family replacements with females accounting for only 1.8% of all donations. Most of the donors were Saudi nationals (92.1%) of whom donors between 18 and 34 years old constituted 87.9%, while those over 40 years old represented only 7.9% of the donations. Pre-donation temporary deferral occurred in 3300 (11.7%) of all potential donation attempts. The most common causes being the recent intake of medication (24.4%) followed by low hemoglobin (14.8%), low or high blood pressure (14.6%), low or high pulse rate (13.6%), and low weight (11.6%).

Conclusion

A profile of blood donors consisting mainly of young male citizens who mostly donated for family replacement was detected. Deferral rate was found to be average when compared to other countries; the causes being similar to those detected in other developed countries. Simple descriptive statistics has shown no marked difference was noted over the 9 years of the study in neither the profile of blood donors nor the cause for temporary deferral of prospective blood donors.

First results of a ferritin-based blood donor deferral policy in the Netherlands

BACKGROUND

Whole blood donors are at risk of becoming iron deficient. To monitor iron stores, Sanquin implemented a new deferral policy based on ferritin levels, in addition to the traditional hemoglobin measurements.

METHODS

Ferritin levels are determined in every fifth donation, as well as in all first-time donors. Donors with ferritin levels <15 ng/mL (WHO threshold) are deferred for 12 months; those ≥15 and ≤30 ng/mL for 6 months. The first results were analyzed and are presented here.

RESULTS

The results show that 25% of women (N = 20151, 95% CI 24%-25%) and 1.6% of men (N = 10391, 95% CI 1.4%-1.8%) have ferritin levels ≤30 ng/mL at their first blood center visit. For repeat (non-first-time) donors, these proportions are higher: 53% of women (N = 28329, 95% CI 52%-54%) and 42% of men (N = 31089, 95% CI 41%-43%). After a 6-month deferral, in 88% of returning women (N = 3059, 95% CI 87%-89%) and 99% of returning men (N = 3736, 95% CI 98%-99%) ferritin levels were ≥15 ng/mL. After a 12-month deferral, in 74% of returning women (N = 486, 95% CI 70%-78%) and 95% of returning men (N = 479, 95% CI 94%-97%) ferritin levels increased to ≥15 ng/mL.

CONCLUSION

Deferral of donors whose pre-donation ferritin levels were ≤30 ng/mL might prevent donors from returning with ferritin levels <15 ng/mL. This policy is promising to mitigate effects of repeated donations on iron stores.

Do deferred donors continue their donations? A large-scale register study on whole blood donor return in the Netherlands

BACKGROUND

Temporary deferral of whole blood donors is essential for a safe blood supply, yet deferral may impact donor return. Different deferral reasons may differently affect return, and donor experience may interfere with this. Therefore, we studied the joint effect of deferral reason and donor experience on return.

STUDY DESIGN AND METHODS

We used a large‐scale retrospective cohort design including all Dutch donors with a whole blood donation attempt in 2013 to 2015 (n = 343,825). We established details of the target donation (including deferral reason if applicable), details of attendances in the 2 years after the target donation, donor characteristics (blood type, sex, age), and donor experience (first‐time, novice, experienced, reactivated). Descriptive statistics as well as time‐to‐events methods were used.

RESULTS

Experienced donors were most likely to return, even after deferral (nondeferred 96% vs. deferred 92%). First‐time and reactivated donors were less likely to return after deferral (69 and 61%, respectively) compared to their nondeferred counterparts (82 and 76%, respectively). First‐time hemoglobin (Hb)‐deferred donors were less likely to return and slower to return than other donors. Similar results were found for reactivated donors deferred for short‐term medical reasons.

CONCLUSION

Deferral reason and donor experience individually as well as jointly impacted donor return. Particularly first‐time and reactivated donors were at risk of nonreturn, especially when deferred for Hb or short‐term medical reasons, respectively. Blood banks designing and implementing donor retention strategies should thus not only take successful but also unsuccessful donation experiences and different experience levels into account.

Elevated risk for iron depletion in high-school age blood donors

BACKGROUND

High school students 16 to 18 years-old contribute 10% of the US blood supply. Mitigating iron depletion in these donors is important because they continue to undergo physical and neurocognitive development.

STUDY DESIGN AND METHODS

Study objectives were to determine the prevalence of iron depletion in 16- to 18-year-old donors and whether their risk for iron depletion was greater than adult donors. Successful, age-eligible donors were enrolled from high school blood drives at two large US blood centers. Plasma ferritin testing was performed with ferritin less than 12 ng/mL as our primary measure of iron depletion and ferritin less than 26 ng/mL a secondary measure. Multivariable repeated-measures logistic regression models evaluated the role of age and other demographic/donation factors.

RESULTS

Ferritin was measured from 4265 enrollment donations September to November 2015 and 1954 follow-up donations through May 2016. At enrollment, prevalence of ferritin less than 12 ng/mL in teenagers was 1% in males and 18% in females making their first blood donation, and 8% in males and 33% in females with prior donations. Adjusted odds for ferritin less than 12 ng/mL were 2.1 to 2.8 times greater in 16- to 18-year-olds than in 19- to 49-year-olds, and for ferritin less than 26 ng/mL were 3.3- to 4.7-fold higher in 16- to 18-year-olds. Progression to hemoglobin deferral was twice as likely in 16- to 18-year-old versus 19- to 49-year-old females.

CONCLUSION

Age 16 to 18 years-old is an independent risk factor for iron deficiency in blood donors at any donation frequency. Blood centers should implement alternate eligibility criteria or additional safety measures to protect teenage donors from iron depletion.

Association of blood donation with iron deficiency among adolescent and adult females in the United States: a nationally representative study

BACKGROUND

Blood donation results in a loss of iron stores, which is particularly concerning for young female blood donors. This study examines the association of blood donation and iron deficiency among adolescent and adult females in the United States.

STUDY DESIGN AND METHODS

A cross-sectional analysis was performed using data from the 1999-2010 National Health and Nutrition Examination Survey (NHANES). Females who reported their blood donation history in the preceding year and had serum ferritin (SF) measurements were included. Analyses were weighted and stratified by adolescents (16-19 years; n = 2419) and adults (20-49 years; n = 7228). Adjusted prevalence ratios (aPRs) were estimated by multivariable Poisson regression. Standard errors were estimated by Taylor series linearization.

RESULTS

Geometric mean SF levels (ng/mL) were lower in blood donors compared to nondonors among adolescents (21.2 vs. 31.4; p < 0.001) and among adults (26.2 vs. 43.7; p < 0.001). The prevalence of absent iron stores (SF < 12 ng/mL) was higher in blood donors compared to nondonors among adolescents (22.6% vs. 12.2%; aPR = 2.03 [95% confidence interval (CI) = 1.45-2.85]) and among adults (18.3% vs. 9.8%; aPR = 2.06 [95% CI = 1.48-2.88]). Additionally, the prevalence of iron deficiency anemia (SF < 26 ng/mL and hemoglobin < 12.0 g/dL) was also higher in blood donors compared to nondonors among adolescents (9.5% vs. 6.1%; aPR = 2.10 [95% CI = 1.13-3.90]) and among adults (7.9% vs. 6.1%; aPR = 1.74 [95% CI = 1.06-2.85]). Similar results were observed in a sensitivity analysis restricted to adolescents aged 16 to 18 years.

CONCLUSIONS

Blood donation is associated with iron deficiency among adolescent and adult females in the United States. These national data call for further development and implementation of blood donation practices aimed toward mitigating iron deficiency.

Safety of blood donation by individuals over age 70 and their contribution to the blood supply in five developed countries: a BEST Collaborative group study

BACKGROUND

Some countries impose an upper age limit on whole blood and double RBC donation while others do not. We evaluated the safety of blood donation in older individuals (≥71 years), and their contribution to the blood supply of five countries.

STUDY DESIGN AND METHODS

Twelve blood center members of the Biomedical Excellence for Safer Transfusion (BEST) Collaborative from four countries with no upper age limit for whole blood and double RBC donation (Canada, New Zealand, England, and the United States) or an upper age limit of 80 (Australia) provided 2016 data on donors and donations, deferral rates, and vasovagal reactions by donor age and sex. Donors under age 24 were included in the number of total donors and donations, but not in deferral and reaction rate comparisons.

RESULTS

Older donors accounted for 1.0% (New Zealand) to 4.3% (United States) of donors, and 1.5% (New Zealand) to 5.6% (United States) of donations; most were between ages 71 and 76. The deferral rate was higher in older compared to 24- to 70-year-old males, but very similar between older and younger females. In contrast, vasovagal reaction rates were either lower (male donors) or similar (female donor for reactions with loss of consciousness) in older compared to 24- to 70-year-old donors.

CONCLUSIONS

Exclusion solely based on older age appears to be unwarranted based on safety concerns such as donor reactions. Healthy older individuals can continue to safely donate and make a significant contribution to the blood supply past arbitrary age limits.

Seroprevalence of Dengue and Zika Virus in Blood Donations: A Systematic Review

The presence of antibodies to Zika virus (ZIKV) and dengue virus (DENV) can be detected in blood donations. Donation-based surveillance provides an alternative strategy to estimate population prevalence by detecting antibodies that are circulating. To estimate population prevalence, we conducted a systematic review of literature on the seroprevalence of ZIKV and DENV antibodies in blood donations. We searched PubMed and Web of Science for studies that reported the seroprevalence of ZIKV and DENV in blood donations. The title and abstract of each study were screened by 2 reviewers simultaneously for possible inclusion, and the full text of selected studies was reviewed to ensure that they met inclusion criteria (used primary data collection, reported evidence of immunoglobulin M (IgM) or immunoglobulin G (IgG) antibodies in the blood supply, and included a representative sample of the total population). Immunoglobin test measuring levels of antibodies to IgM and IgG and number of positive cases were extracted from each study. No exclusions were made based on language or country. Our initial search identified 1890 studies after excluding duplicates, of which 76 were assessed for full text eligibility to ensure that they met our final inclusion criteria. There were 14 studies included in our review; 11 examined the seroprevalence of DENV, and 3 examined ZIKV. The highest seroprevalence by IgM was 2.82% for DENV and 0.53% for ZIKV. Our results indicate that the seroprevalence of ZIKV and DENV antibody presence in countries with active transmission is higher than reports by traditional surveillance in some countries. This finding is expected due to the large percentage of asymptomatic cases. The highest seroprevalence was observed for IgG, which can persist over long periods of time compared to IgM. Screening of blood donations may help supplement traditional surveillance measures, especially during outbreak settings.

Distribution of hepatitis A antibodies in US blood donors

BACKGROUND

Recently, there has been an increase in the number of hepatitis A outbreaks in the United States. Although the presence of hepatitis A virus (HAV) RNA in blood donors is known to be low, HAV antibody prevalence in this population is unknown.

STUDY DESIGN AND METHODS

Samples from 5001 US blood donors collected primarily in the midwestern United States in 2015 were tested for the presence of HAV IgG antibodies using chemiluminescent microparticle immunoassays on the ARCHITECT platform (Abbott Laboratories).

RESULTS

The overall prevalence of IgG anti-HAV was 60%. Only one specimen was IgM anti-HAV positive, for an incidence of 0.02%. IgG anti-HAV prevalence among donors aged 16 to 19 years was 67%, decreased to 54% among donors aged 40 to 49 years and increased to 70% among donors aged 80 to 93 years. No differences were seen by sex with overall IgG anti-HAV prevalence of 61% and 60% for males and females, respectively. Among the five states (Illinois, Indiana, Kansas, Kentucky, and Missouri) with the highest number of donors tested, IgG anti-HAV prevalence in Missouri (65%) was significantly higher (p <0.01) than that in Illinois (52%) or Kentucky (59%). No other significant differences between states were noted.

CONCLUSION

This study demonstrates the overall high rates of IgG anti-HAV in US blood donors, with the low associated risk of HAV transfusion transmission likely the result of low incidence and effective vaccination.

Disparities in detection of antibodies against hepatitis E virus in US blood donor samples using commercial assays

BACKGROUND

Reported hepatitis E virus (HEV) antibody assay performance characteristics are variable. Using a subset of surplus US blood donation samples, we compared assays for detecting anti-HEV immunoglobulin M (Ig)M and IgG or total anti-HEV antibodies.

STUDY DESIGN AND METHODS

Samples from 5040 random blood donations, all HEV-RNA negative, collected primarily in the midwestern United States in 2015 were tested for anti-HEV IgM and IgG or total anti-HEV using assays manufactured by Diagnostic Systems, Wantai, and MP Biomedicals.

RESULTS

Overall, the percentage of detection for anti-HEV IgG and total anti-HEV was 11.4%, and for anti-HEV IgM was 1.8%. Nine samples were reactive for anti-HEV IgM by all assays, giving a recent infection rate of 0.18%. Anti-HEV IgG/total anti-HEV detection rates increased with age. Interassay agreement was higher among the IgG anti-HEV/total anti-HEV assays (84%) than the IgM assays (22%). Regression analyses of signal-to-cutoff ratios from IgG/total antibody assay were heteroskedastic, indicating no constant variance among these assays, suggesting they may detect different epitopes or were affected by waning or less avid antibodies in the US donor population.

CONCLUSIONS

Although similar percentages of IgG anti-HEV/total anti-HEV detection were observed across the three commercial assays, each assay detected a unique sample subpopulation and was heteroskedastic when compared pairwise. Discordance was higher among anti-HEV IgM assays, but a recent HEV infection rate of at least 0.18% was estimated based on assay concordance.