This review examines the recent research on the prevalence, determinants and importance of low iron in blood donors, and on the efforts to reduce or prevent iron depletion in donor populations.Female donors, especially younger women, are at highest risk for donation-induced low iron, but menopausal women and high-frequency donors of both sexes also face considerable risk for iron depletion. Predonation screening for hemoglobin contributes little information on donor iron status. Consumption of supplemental iron is helpful in preventing or reversing low iron, and waiting longer between donations also facilitates the recovery of the iron lost through donation.Although the impact of phlebotomy-related iron depletion on donor health requires better documentation, measures are available now that can be deployed on a targeted or standardized basis. Blood centers, regulators, and donors should continue to evaluate different approaches for addressing this problem, with the likely outcome that no single measure is optimal for maintaining adequate collections while safeguarding donor health.
Abstract Background Frequent blood donors who contribute multiple times annually are important for maintaining an adequate blood supply. However, repeated donations exacerbate iron deficiency, which can lead to pica, a condition characterised as repeated eating or chewing of a non‐nutritious substance such as ice, clay and dirt. Understanding characteristics of frequent donors that are associated with increased risk for developing pica will help to identify them and prevent this adverse consequence of blood donation. Methods Demographic, clinical, haematological, and biochemical factors associated with pica were investigated using univariable and multivariable logistic regression analysis in a cohort of 1693 high‐intensity donors who gave nine or more units of whole blood in the preceding 2 years. Pica was classified by questionnaire responses as consuming at least 8 oz of ice daily and/or consumption of non‐ice substances regardless of the amount and frequency. Results Pica was present in 1.5% of the high‐intensity donors, and only occurred in those with ferritin <50 ng/ml . Of 16 candidate variables, only haematocrit (OR = 0.835, p = 0.020) was independently associated with pica. Although severe iron deficiency was more prevalent in high‐intensity donors, pica behaviours were less prevalent than in less frequent donors (2.2%). Conclusion We have uncovered predictors of pica in high‐intensity donors, which further emphasises the need to continue to implement iron replacement programs to reduce the prevalence of pica and maintain a robust pool of frequent donors.
Introduction: Babesia is a tick-borne intraerythrocytic parasite that is globally ubiquitous, yet understudied. Several species of Babesia have been shown to be transfusion-transmissible. Babesia has been reported in blood donors, animals, and ticks in the Tyrol (Western Austria), and regional cases of human babesiosis have been described. We sought to characterize the risk of Babesia to the local blood supply. Methods: Prospective molecular testing was performed on blood donors who presented to regional, mobile blood collection drives in the Tyrol, Austria (27 May to October 4, 2021). Testing was conducted using the cobas® Babesia assay (Roche Molecular Systems, Inc.), a commercial PCR assay approved for blood donor screening that is capable of detecting the 4 primary species causing human babesiosis (i.e., B. microti, B. divergens, B. duncani, and B. venatorum). A confirmatory algorithm to manage initial PCR-reactive samples was developed, as were procedures for donor and product management. Results: A total of 7,972 donors were enrolled and screened; 4,311 (54.1%) were male, with a median age of 47 years (IQR = 34–55). No positive cases of Babesia were detected, corresponding with an overall prevalence of 0.00% (95% CI: 0.00%, 0.05%). Discussion: The findings suggest that the prevalence of Babesia is low in Austrian blood donors residing in the Tyrol, even during months of peak tick exposure. Although one cannot conclude the absence of Babesia in this population given the limited sample size, the findings suggest that the regional risk of transfusion-transmitted babesiosis is low.
Restless legs syndrome (RLS) is a common sensorimotor disorder, which can disrupt sleep and is thought to be caused in part by low cellular iron stores. Proton pump inhibitors (PPI) and histamine H2-receptor antagonists (H2A) are among the most commonly used drugs worldwide and show evidence of causing iron deficiency. We conducted a case/non-case observational study of blood donors in the United States (N = 13,403; REDS-III) and Denmark (N = 50,323; Danish Blood Donor Study, DBDS), both of which had complete blood count measures and a completed RLS assessment via the Cambridge-Hopkins RLS questionnaire. After adjusting for age, sex, race, BMI, blood donation frequency, smoking, hormone use, and iron supplement use, PPI/H2A use was associated with RLS (odds ratio [OR] = 1.41; 95% confidence interval [CI], 1.13-1.76; p = 0.002) in REDS-III for both PPI (OR = 1.43; CI, 1.03-1.95; p = 0.03) and H2A (OR = 1.56; CI, 1.10-2.16; p = 0.01). DBDS exhibited a similar association with PPIs/H2As (OR = 1.29; CI, 1.20-1.40; p < 0.001), and for PPIs alone (OR = 1.27; CI, 1.17-1.38; p < 0.001), but not H2As alone (OR = 1.18; CI, 0.92-1.53; p = 0.2). We found no evidence of blood iron stores mediating this association. The association of PPI, and possibly H2A, consumption with RLS independent of blood iron status and other factors which contribute to RLS risk suggest the need to re-evaluate use of PPI/H2A in populations at particular risk for RLS.
Many parasites that infect humans have a blood-borne phase and can be transmitted in blood products. In the United States the risk of transfusion transmission of parasites is low, but varies with the risk for acquisition of infection and a given organism's characteristics affecting presence and duration of asymptomatic parasitemia and survival of component manufacturing and storage. Plasmodium parasites are highly transmissible, but risk is effectively mitigated by exclusion of donors identified as having known or potential exposure to malaria; serologic or nucleic acid testing of select donors is a useful complement in other countries. Trypanosoma cruzi, the cause of Chagas disease, is present in many US residents, but serological testing of donors has sharply reduced transmission risk. Babesia microti and other agents of human babesiosis are the most commonly transmitted parasite in the US, with risk greatest in regions with highest rates of transmission in nature. Documented risk following introduction of national surveillance is roughly 1 per million transfusions, but actual risk is undoubtedly higher due to lack of detection. Approval of screening assays or pathogen inactivation technologies for whole blood or red cell products will enhance blood safety since donor exclusion is of limited efficacy against Babesia parasites.
Changes in testing behaviors and reporting requirements have hampered the ability to estimate the U.S. SARS-CoV-2 incidence (1). Hybrid immunity (immunity derived from both previous infection and vaccination) has been reported to provide better protection than that from infection or vaccination alone (2). To estimate the incidence of infection and the prevalence of infection- or vaccination-induced antibodies (or both), data from a nationwide, longitudinal cohort of blood donors were analyzed. During the second quarter of 2021 (April-June), an estimated 68.4% of persons aged ≥16 years had infection- or vaccination-induced SARS-CoV-2 antibodies, including 47.5% from vaccination alone, 12.0% from infection alone, and 8.9% from both. By the third quarter of 2022 (July-September), 96.4% had SARS-CoV-2 antibodies from previous infection or vaccination, including 22.6% from infection alone and 26.1% from vaccination alone; 47.7% had hybrid immunity. Prevalence of hybrid immunity was lowest among persons aged ≥65 years (36.9%), the group with the highest risk for severe disease if infected, and was highest among those aged 16-29 years (59.6%). Low prevalence of infection-induced and hybrid immunity among older adults reflects the success of public health infection prevention efforts while also highlighting the importance of older adults staying up to date with recommended COVID-19 vaccination, including at least 1 bivalent dose.*,†.
BACKGROUND The optimal approach for reducing iron depletion (ID) in blood donors may vary depending on biologic or behavioral differences across donors. STUDY DESIGN AND METHODS More than 12,600 successful whole blood donors were enrolled from four US blood centers for ferritin testing. The study population was enriched for racial/ethnic minorities (1605 African American, 1616 Asian, 1023 Hispanic). Subjects completed questionnaires on ID risk factors. Logistic regression identified predictors of absent iron stores (AIS; ferritin <12 ng/mL) and low ferritin (LF; ferritin <26 ng/mL). RESULTS Across all subjects, 19% had AIS and 42% had LF, with a sharp increase in risk observed with increasing donation intensity and among women a large decrease in risk in those more than 50 years old. When other factors were controlled for, African American and Asian donors showed 20% to 25% decreased risk for AIS compared to non‐Hispanic Caucasian donors, while Hispanic donors had 25% higher risk. Daily iron supplementation reduced risk for LF and AIS by 30% to 40%, respectively, while the benefit from less frequent use was lower (7%‐19% protection). Regular antacid use was associated with at least 20% increment to risk. Use of oral contraceptives or estrogen in females reduced risk by 16% to 22%, while males who reported supplemental testosterone use had a 50% to 125% greater risk for LF and AIS. CONCLUSIONS This study confirms high prevalence of LF and AIS in US donors and the principal risk factors of age, sex, and donation frequency. Additional demographic and behavioral risk factors of secondary importance might allow for refinement of ID mitigation strategies.
Pica is characterized as repeatedly eating or chewing a non-nutritious substance including, but not limited to ice, clay and dirt, starch, raw pasta, chalk, coal, paint, or paper. Pica symptoms can be intense and addiction-like and disrupt quality of life. It is strongly linked to iron deficiency. Since substantial iron loss occurs during blood donation, blood donors may be susceptible to development of pica behaviors.We investigated demographic, clinical, hematological, and biochemical factors associated with pica using univariable and multivariable logistic regression analysis in a cohort of 11,418 racially diverse blood donors. Pica was defined by questionnaire responses as consuming at least 8 oz of ice daily and/or consumption of non-ice substances regardless of the amount and frequency.Pica was present in 2.2% of the donors. The sensitivity and specificity of pica in iron-deficient donors were 36% and 82%, respectively. Lower ferritin (p = .001), non-Asian race (p < .001), higher red cell distribution width (p < .001), younger age, and restless legs syndrome (p = .008) were independently associated with pica. Female sex is associated with iron deficiency but was not an independent predictor of pica suggesting that iron deficient males and females were equally susceptible to the development of pica behaviors. Donors with normal ferritin levels also reported pica, reinforcing the role of non-iron related factors in its presentation.We have identified demographic, clinical, and biochemical predictors of pica that help identify those most at risk for developing pica behaviors, and thereby assist in its clinical diagnosis and treatment.
