Blood donor return behavior in South Africa and the United States before and during the COVID-19 pandemic.

BACKGROUND: Studies preceding the COVID-19 pandemic found that slower time-to-return was associated with first-time, deferred, and mobile drive blood donors. How donor return dynamics changed during the COVID-19 pandemic is not well understood. METHODS: We analyzed visits by whole blood donors from 2017 to 2022 in South Africa (SA) and the United States (US) stratified by mobile and fixed environment, first-time and repeat donor status, and pre-COVID19 (before March 2020) and intra-COVID19. We used Kaplan-Meier curves to characterize time-to-return, cumulative incidence functions to analyze switching between donation environments, and Cox proportional hazards models to analyze factors influencing time-to-return. RESULTS: Overall time-to-return was shorter in SA. Pre-COVID19, the proportion of donors returning within a year of becoming eligible was lower for deferred donors in both countries regardless of donation environment and deferral type. Intra-COVID19, the gap between deferred and non-deferred donors widened in the US but narrowed in SA, where efforts to schedule return visits from deferred donors were intensified, particularly for non-hemoglobin-related deferrals. Intra-COVID19, the proportion of donors returning within a year in SA was higher for deferred first-time donors (>81%) than for successful first-time donors (80% at fixed sites; 69% at mobile drives). CONCLUSIONS: The pandemic complicated efforts to recruit new donors and schedule returning visits after completed donations. Concerted efforts to improve time-to-return for deferred donors helped mitigate donation loss in SA during the public health emergency.

The impact of non-disclosure of HIV status and antiretroviral therapy on HIV recency testing and incidence algorithms.

BACKGROUND AND OBJECTIVES: Accurate HIV incidence estimates among blood donors are necessary to assess the effectiveness of programs aimed at limiting transfusion-transmitted HIV. We assessed the impact of undisclosed HIV status and antiretroviral (ARV) use on HIV recency and incidence estimates using increasingly comprehensive recent infection testing algorithms. MATERIALS AND METHODS: Using 2017 donation data from first-time and lapsed donors, we populated four HIV recency algorithms: (1) serology and limiting-antigen avidity testing, (2) with individual donation nucleic amplification testing (ID-NAT) added to Algorithm 1, (3) with viral load added to Algorithm 2 and (4) with ARV testing added to Algorithm 3. Algorithm-specific mean durations of recent infection (MDRI) and false recency rates (FRR) were calculated and used to derive and compare incidence estimates. RESULTS: Compared with Algorithm 4, progressive algorithms misclassified fewer donors as recent: Algorithm 1: 61 (12.1%); Algorithm 2: 14 (2.8%) and Algorithm 3: 3 (0.6%). Algorithm-specific MDRI and FRR values resulted in marginally lower incidence estimates: Algorithm 1: 0.19% per annum (p.a.) (95% confidence interval [CI]: 0.13%-0.26%); Algorithm 2: 0.18% p.a. (95% CI: 0.13%-0.22%); Algorithm 3: 0.17% p.a. (95% CI: 0.13%-0.22%) and Algorithm 4: 0.17% p.a. (95% CI: 0.13%-0.21%). CONCLUSION: We confirmed significant misclassification of recent HIV cases when not including viral load and ARV testing. Context-specific MDRI and FRR resulted in progressively lower incidence estimates but did not fully account for the context-specific variability in incidence modelling. The inclusion of ARV testing, in addition to viral load and ID-NAT testing, did not have a significant impact on incidence estimates.

The evolution and interpretation of seroprevalence of SARS-CoV-2 antibodies among South African blood donors from the Beta to Omicron variant-driven waves.

BACKGROUND AND OBJECTIVES: Confirmed COVID-19 diagnoses underestimate the total number of infections. Blood donors can provide representative seroprevalence estimates, which can be leveraged into reasonable estimates of total infection counts and infection fatality rate (IFR). MATERIALS AND METHODS: Blood donors who donated after each of three epidemic waves (Beta, Delta and first Omicron waves) were tested for anti-SARS-CoV-2 nucleocapsid antibodies using the Roche Elecsys anti-SARS-CoV-2 total immunoglobulin assay. Roche Elecsys anti-spike antibody testing was done for the post-Omicron sampling. Prevalence of antibodies was estimated by age, sex, race and province and compared to official case reporting. Province and age group-specific IFRs were estimated using external excess mortality estimates. RESULTS: The nationally weighted anti-nucleocapsid seroprevalence estimates after the Beta, Delta and Omicron waves were 47% (46.2%-48.6%), 71% (68.8%-73.5%) and 87% (85.5%-88.4%), respectively. There was no variation by age and sex, but there were statistically and epidemiologically significant differences by province (except at the latest time point) and race. There was a 13-fold higher seroprevalence than confirmed case counts at the first time point. Age-dependent IFR roughly doubled for every 10 years of age increase over 6 decades from 0.014% in children to 6.793% in octogenarians. CONCLUSION: Discrepancies were found between seroprevalence and confirmed case counts. High seroprevalence rates found among Black African donors can be ascribed to historical inequities. Our IFR estimates were useful in refining previous large disagreements about the severity of the epidemic in South Africa. Blood donor-based serosurveys provided a valuable and efficient way to provide near real-time monitoring of the ongoing SARS-CoV-2 outbreak.

The potential contribution of house crickets to the dietary zinc content and nutrient adequacy in young Kenyan children: a linear programming analysis using Optifood.

Zn deficiency arising from inadequate dietary intake of bioavailable Zn is common in children in developing countries. Because house crickets are a rich source of Zn, their consumption could be an effective public health measure to combat Zn deficiency. This study used Optifood, a tool based on linear programming analysis, to develop food-based dietary recommendations (FBR) and predict whether dietary house crickets can improve both Zn and overall nutrient adequacy of children's diets. Two quantitative, multi-pass 24-h recalls from forty-seven children aged 2 and 3 years residing in rural Kenya were collected and used to derive model parameters, including a list of commonly consumed foods, median serving sizes and frequency of consumption. Two scenarios were modelled: (i) FBR based on local available foods and (ii) FBR based on local available foods with house crickets. Results revealed that Zn would cease to be a problem nutrient when including house crickets to children's diets (population reference intake coverage for Zn increased from 89 % to 121 % in the best-case scenario). FBR based on both scenarios could ensure nutrient adequacy for all nutrients except for fat, but energy percentage (E%) for fat was higher when house crickets were included in the diet (23 E% v. 19 E%). This manoeuvre, combined with realistic changes in dietary practices, could therefore improve dietary Zn content and ensure adequacy for twelve nutrients for Kenyan children. Further research is needed to render these theoretical recommendations, practical.

Motivations for blood donation by HIV-positive individuals on antiretrovirals in South Africa: A qualitative study.

OBJECTIVES: We performed a mixed-methods study to explore the motivations associated with blood donation by donors with known, but undisclosed HIV-positive status and ARV use (HIV+/ARV+), seeking potential strategies to reduce such donations and mitigate risk for blood recipients. Here, we report predominantly the qualitative component. BACKGROUND: A safe and sustainable blood supply is dependent in part, on effective pre-donation donor assessment. We previously described failure by HIV+/ARV+ blood donors to disclose their status. Such donations may lead to transfusion-transmitted HIV. METHODS: The social ecological model provided the conceptual framework for this study. Previously identified HIV+/ARV+ donors were invited to complete a survey (including a validated stigma scale) and qualitative interview, which underwent inductive and deductive thematic analysis. RESULTS: We uncovered two primary motivational paths to HIV+/ARV+ blood donations: privacy and altruism. The latter included a motivation not previously reported in the literature: donating specifically for other people living with HIV (PLWH). The other primary factor was a lack of privacy. These accounts often included donors encountering donation opportunities when accompanied by people to whom they had not and did not plan to disclose their HIV status. Most were highly confident their donations would be identified as HIV-positive and discarded. CONCLUSION: We demonstrated a complex interaction between individual, social, cultural, and structural/policy factors in blood donations by PLWH who take ARV. Recommendations to limit HIV + ARV+ donations include: (1) Targeted communication strategies to increase knowledge among PLWH of their deferral from blood donation-without increasing stigma, and (2) development of procedures to assist those who feel unable to opt-out of donation due to privacy concerns.

Emotional and non-emotional mental imagery and auditory verbal hallucinations (hearing voices): A systematic review of imagery assessment tools.

It is unknown to what extent mental imagery and auditory verbal hallucinations (AVHs) are related. Trials evaluating this issue used both emotional and non-emotional mental imagery tools, thereby complicating outcomes comparisons. Therefore, the present study aimed to systematically review the literature on mental imagery in individuals with AVHs to (1) inventory imagery assessment tools used in this population, (2) to collect information on the relation between emotional and non-emotional mental imagery in all sensory domains and AVHs and (3) to integrate the outcomes of this systematic review in a model of different mental imagery domains and related assessment tools. We conducted a systematic literature search in the PubMed Database. After full-text screening, 17 papers were included. Findings showed that a variety of assessment methods have been used to assess various aspects of mental imagery in people with AVHs, suggesting that there is a lack of agreed theoretical conceptualization of mental imagery and AVHs. In addition, the studies confirmed as was expected that non-emotional mental imagery seemed unrelated to AVHs whereas emotional mental imagery was related to AVHs. Lastly, we proposed a model of mental imagery domains and corresponding assessment methods distinguishing between emotional and non-emotional mental imagery.

Management of blood transfusion services in low-resource countries.

BACKGROUND AND OBJECTIVES: Enabling universal access to safe blood components should be a key component of every country's national healthcare strategy. This study aimed to assess the current status of infrastructure and resources of blood transfusion services (BTS) in low- and middle-income countries. MATERIALS AND METHODS: A cross-sectional survey was designed to gather information on blood donations, components, redistribution, testing resources and quality management systems (QMSs). The survey was distributed to the International Society of Blood Transfusion members between October 2021 and November 2021. RESULTS: A total of 54 respondents from 20 countries responded to the survey. This included hospital-based BTS/blood centres (46%), national blood centres (11%)and national and regional blood services (11%). Voluntary non-remunerated, replacement and paid donors accounted for 94.2%, 84.6% and 21.1% of donations, respectively. Apheresis donation was available in 59.6% of institutions. National/regional criteria for redistribution of blood components were reported by 75.9% of respondents. Blood components incurred payment charges in 81.5% of respondents' institutions, and payments were borne by patients in 50% of them. Testing methods, such as manual (83%), semi-automated (68%) or fully automated (36.2%), were used either alone or in combination. QMSs were reported in 17 institutions, while accreditation and haemovigilance were reported in 12 and 8 countries, respectively. CONCLUSION: QMS was implemented in most of the countries despite the common use of paid donations and the lack of advanced testing. Efforts to overcome persistent challenges and wider implementation of patient blood management programmes are required.

Early and out-of-hospital use of COVID-19 convalescent plasma: An international assessment of utilization and feasibility.

BACKGROUND AND OBJECTIVES: The use of coronavirus disease 2019 (COVID-19) convalescent plasma (CCP) in the treatment of patients with severe acute respiratory syndrome-2 infection has been controversial. Early administration of CCP before hospital admission offers a potential advantage. This manuscript summarizes current trials of early use of CCP and explores the feasibility of this approach in different countries. MATERIALS AND METHODS: A questionnaire was distributed to the International Society of Blood Transfusion (ISBT) CCP working group. We recorded respondents' input on existing trials on early/outpatient CCP and out-of-hospital (OOH)/home transfusion (HT) practices in their countries and feedback on challenges in initiating home CCP infusion programmes. In addition, details of existing trials registered on clinicaltrials.gov were summarized. RESULTS: A total of 31 country representatives participated. Early/OOH CCP transfusion studies were reported in the United States, the Netherlands, Spain and Brazil. There were a total of six published and five ongoing trials on the prophylactic and therapeutic early use of CCP. HT was practised in Australia, the UK, Belgium, France, Japan, Nigeria, the Netherlands, Spain, Italy, Norway, the United States and some provinces in Canada. Thirty-four representatives indicated a lack of OOH CCP or HT in their institutions and countries. Barriers to implementation of OOH/HT included existing legislation, lack of policies pertaining to outpatient transfusion, and associated logistical challenges, including lack of staffing and resources. CONCLUSION: Early administration of CCP remains a potential option in COVID-19 management in countries with existing OOH/HT programmes. Legislation and regulatory bodies should consider OOH/HT practice for transfusion in future pandemics.

International Society of Blood Transfusion survey of experiences of blood banks and transfusion services during the COVID-19 pandemic.

BACKGROUND AND OBJECTIVES: The coronavirus disease 2019 (COVID-19) pandemic has impacted blood systems worldwide. Challenges included maintaining blood supplies and initiating the collection and use of COVID-19 convalescent plasma (CCP). Sharing information on the challenges can help improve blood collection and utilization. MATERIALS AND METHODS: A survey questionnaire was distributed to International Society of Blood Transfusion members in 95 countries. We recorded respondents' demographic information, impacts on the blood supply, CCP collection and use, transfusion demands and operational challenges. RESULTS: Eighty-two responses from 42 countries, including 24 low- and middle-income countries, were analysed. Participants worked in national (26.8%) and regional (26.8%) blood establishments and hospital-based (42.7%) institutions. CCP collection and transfusion were reported by 63% and 36.6% of respondents, respectively. Decreases in blood donations occurred in 70.6% of collecting facilities. Despite safety measures and recruitment strategies, donor fear and refusal of institutions to host blood drives were major contributing factors. Almost half of respondents working at transfusion medicine services were from large hospitals with over 10,000 red cell transfusions per year, and 76.8% of those hospitals experienced blood shortages. Practices varied in accepting donors for blood or CCP donations after a history of COVID-19 infection, CCP transfusion, or vaccination. Operational challenges included loss of staff, increased workloads and delays in reagent supplies. Almost half of the institutions modified their disaster plans during the pandemic. CONCLUSION: The challenges faced by blood systems during the COVID-19 pandemic highlight the need for guidance, harmonization, and strengthening of the preparedness and the capacity of blood systems against future infectious threats.

Adherence to the Dutch healthy diet index and change in glycemic control and cardiometabolic markers in people with type 2 diabetes.

PURPOSE: To investigate whether adherence to the Dutch Healthy Diet index 2015 (DHD15-index) is associated with change in glycemic control and cardio-metabolic markers over two-year follow-up in people with type 2 diabetes (T2D). METHODS: This prospective cohort study included 1202 individuals with T2D (mean age 68.7 ± 9.0 years; 62.5% male; mean HbA1c 53.8 ± 11.7 mmol/mol) from the Diabetes Care System cohort. Baseline dietary intake was assessed using a validated food frequency questionnaire, and adherence to the DHD15-index was estimated (range 0-130). HbA1c, fasting glucose, blood lipids (HDL and LDL cholesterol, cholesterol ratio), blood pressure, estimated glomerular filtration rate (eGFR), and BMI were measured at baseline, and after one- and two-year follow-up. Linear mixed model analyses were conducted to examine the associations between adherence to the DHD15-index and glycemic control and the cardio-metabolic outcomes, adjusting for energy intake, sociodemographic and lifestyle characteristics, and medication. RESULTS: Highest adherence (T3) to the DHD15-index was not associated with change in HbA1c, compared to lowest adherence (T1) [ßT3vsT1: 0.62 mmol/mol (- 0.94; 2.19), Ptrend = 0.44]. There was a non-linear association with fasting glucose, where moderate adherence (T2) was associated with a decrease in fasting glucose [ßT2vsT1: - 0.29 mmol/L (- 0.55; - 0.03), Ptrend = 0.30]. Higher adherence to the DHD15-index was associated with a decrease in BMI [ß10point: - 0.41 kg/m2 (- 0.60; - 0.21), Ptrend < 0.001], but not with blood lipids, blood pressure or kidney function. CONCLUSION: In this well-controlled population of people with T2D, adherence to the DHD15-index was associated with a decrease in BMI, but not with change in glycemic control or other cardio-metabolic parameters.

Undisclosed HIV status and antiretroviral therapy use among South African blood donors.

BACKGROUND: Undisclosed antiretroviral drug (ARV) use among blood donors who tested HIV antibody positive, but RNA negative, was previously described by our group. Undisclosed ARV use represents a risk to blood transfusion safety. We assessed the prevalence of and associations with undisclosed ARV use among HIV-positive donors who donated during 2017. STUDY DESIGN AND METHODS: South African National Blood Service (SANBS) blood donors are screened by self-administered questionnaire, semi-structured interview, and individual donation nucleic acid amplification testing for HIV. Stored samples from HIV-positive donations were tested for ARV and characterized as recent/longstanding using lag avidity testing. RESULTS: Of the 1462 HIV-positive donations in 2017, 1250 had plasma availability for testing of which 122 (9.8%) tested positive for ARV. Undisclosed ARV use did not differ by gender (p = .205) or ethnicity (p = .505) but did differ by age category (p < .0001), donor (p < .0001), clinic type (p = .012), home province (p = .01), and recency (p < .0001). Multivariable logistic regression found older age (adjusted odds ratio [aOR] 3.73, 95% confidence interval [CI] 1.98-7.04 for donors >40 compared with those <21), first-time donation (aOR 5.24; 95% CI 2.48-11.11), and donation in a high HIV-prevalence province (aOR 9.10; 95% CI 2.70-30.72) compared with Northern Rural provinces to be independently associated with undisclosed ARV use. DISCUSSION: Almost 1 in 10 HIV-positive blood donors neglected to disclose their HIV status and ARV use. Demographic characteristics of donors with undisclosed ARV use differed from those noted in other study. Underlying motivations for nondisclosure among blood donors remain unclear and may differ from those in other populations with significant undisclosed ARV use.

Re-engineering the medical assessment of blood donors in South Africa: The balance between supply and safety.

BACKGROUND: The balance between ensuring blood donor and recipient safety while maintaining a sufficient blood supply can be affected by excessive deferral of blood donors. In 2018, a biannual regulatory review of donor eligibility criteria provided the South African National Blood Service (SANBS) the opportunity to review the existing criteria. Changes to these criteria were implemented in April 2019 after an extensive review. STUDY DESIGN AND METHODS: We conducted a cross-sectional study of SANBS whole-blood donor presentations to determine the impact of the changed donor eligibility criteria on deferrals and blood safety. We compared donor presentations, deferrals, and HIV-positive cases for the 12-month period (April 2019-March 2020) after the implementation of the updated donor eligibility criteria to those of the previous year. RESULTS: Of the 2,112,917 donor presentations, 51.1% (1079506) occurred in the post-implementation study period. Overall, deferrals decreased from 18.6% to 14.5%, whereas HIV-positive donations increased by 0.03%. A multivariable logistic regression analysis adjusted for sex, age, geographical location, donor, and clinic type showed significantly lower odds of deferral (OR 0.70; 95% CI: 0.69-0.70) and greater odds of HIV-positive cases in the study period than those in the control period (OR 1.17; 95% CI: 1.10-1.25). CONCLUSION: We confirmed that the change in donor eligibility criteria was associated with a decrease in deferrals and an increase in the country's blood supply. The impact of the increased number of HIV-positive donations on blood safety in a country performing individual donation nucleic acid amplification testing requires further investigation.

Transfusion medicine and blood banking education and training for blood establishment laboratory staff: A review of selected countries in Africa.

BACKGROUND: Avoidable human error is a significant cause of transfusion adverse events. Adequately trained, laboratory staff in blood establishments and blood banks, collectively blood facilities, are key in ensuring high-quality transfusion medicine (TM) services. Gaps in TM education and training of laboratory staff exist in most African countries. We assessed the status of the training and education of laboratory staff working in blood facilities in Africa. STUDY DESIGN AND METHODS: A cross-sectional study using a self-administered pilot-tested questionnaire was performed. The questionnaire comprised 26 questions targeting six themes. Blood facilities from 16 countries were invited to participate. Individually completed questionnaires were grouped by country and descriptive analysis performed. RESULTS: Ten blood establishments and two blood banks from eight African countries confirmed the availability of a host of training programs for laboratory staff; the majority of which were syllabus or curriculum-guided and focused on both theoretical and practical laboratory skills development. Training was usually preplanned, dependent on student and trainer availability and delivered through lecture-based classroom training as well as formal and informal on the job training. There were minimal online didactic and self-directed learning. Teaching of humanistic values appeared to be lacking. CONCLUSION: We confirmed the availability of diverse training programs across a variety of African countries. Incorporation of virtual learning platforms, rather than complete reliance on didactic, in-person training programs may improve the education reach of the existing programs. Digitalization driven by the coronavirus disease 2019 pandemic may provide an opportunity to narrow the knowledge gap in low- and middle-income countries (LMICs).

Clinical use of Convalescent Plasma in the COVID-19 pandemic: a transfusion-focussed gap analysis with recommendations for future research priorities.

BACKGROUND AND OBJECTIVES: Use of convalescent plasma for coronavirus disease 2019 (COVID-19) treatment has gained interest worldwide. However, there is lack of evidence on its dosing, safety and effectiveness. Until data from clinical studies are available to provide solid evidence for worldwide applicable guidelines, there is a need to provide guidance to the transfusion community and researchers on this emergent therapeutic option. This paper aims to identify existing key gaps in current knowledge in the clinical application of COVID-19 convalescent plasma (CCP). MATERIALS AND METHODS: The International Society of Blood Transfusion (ISBT) initiated a multidisciplinary working group with worldwide representation from all six continents with the aim of reviewing existing practices on CCP use from donor, product and patient perspectives. A subgroup of clinical transfusion professionals was formed to draft a document for CCP clinical application to identify the gaps in knowledge in existing literature. RESULTS: Gaps in knowledge were identified in the following main domains: study design, patient eligibility, CCP dose, frequency and timing of CCP administration, parameters to assess response to CCP treatment and long-term outcome, adverse events and CCP application in less-resourced countries as well as in paediatrics and neonates. CONCLUSION: This paper outlines a framework of gaps in the knowledge of clinical deployment of CPP that were identified as being most relevant. Studies to address the identified gaps are required to provide better evidence on the effectiveness and safety of CCP use.

Guidance for the procurement of COVID-19 convalescent plasma: differences between high- and low-middle-income countries.

BACKGROUND AND OBJECTIVES: COVID-19 convalescent plasma (CCP) has been used, predominantly in high-income countries (HICs) to treat COVID-19; available data suggest the safety and efficacy of use. We sought to develop guidance for procurement and use of CCP, particularly in low- and middle-income countries (LMICs) for which data are lacking. MATERIALS AND METHODS: A multidisciplinary, geographically representative group of individuals with expertise spanning transfusion medicine, infectious diseases and haematology was tasked with the development of a guidance document for CCP, drawing on expert opinion, survey of group members and review of available evidence. Three subgroups (i.e. donor, product and patient) were established based on self-identified expertise and interest. Here, the donor and product-related challenges are summarized and contrasted between HICs and LMICs with a view to guide related practices. RESULTS: The challenges to advance CCP therapy are different between HICs and LMICs. Early challenges in HICs related to recruitment and qualification of sufficient donors to meet the growing demand. Antibody testing also posed a specific obstacle given lack of standardization, variable performance of the assays in use and uncertain interpretation of results. In LMICs, an extant transfusion deficit, suboptimal models of donor recruitment (e.g. reliance on replacement and paid donors), limited laboratory capacity for pre-donation qualification and operational considerations could impede wide adoption. CONCLUSION: There has been wide-scale adoption of CCP in many HICs, which could increase if clinical trials show efficacy of use. By contrast, LMICs, having received little attention, require locally applicable strategies for adoption of CCP.

ABO blood group and COVID-19: a review on behalf of the ISBT COVID-19 Working Group.

Growing evidence suggests that ABO blood group may play a role in the immunopathogenesis of SARS-CoV-2 infection, with group O individuals less likely to test positive and group A conferring a higher susceptibility to infection and propensity to severe disease. The level of evidence supporting an association between ABO type and SARS-CoV-2/COVID-19 ranges from small observational studies, to genome-wide-association-analyses and country-level meta-regression analyses. ABO blood group antigens are oligosaccharides expressed on red cells and other tissues (notably endothelium). There are several hypotheses to explain the differences in SARS-CoV-2 infection by ABO type. For example, anti-A and/or anti-B antibodies (e.g. present in group O individuals) could bind to corresponding antigens on the viral envelope and contribute to viral neutralization, thereby preventing target cell infection. The SARS-CoV-2 virus and SARS-CoV spike (S) proteins may be bound by anti-A isoagglutinins (e.g. present in group O and group B individuals), which may block interactions between virus and angiotensin-converting-enzyme-2-receptor, thereby preventing entry into lung epithelial cells. ABO type-associated variations in angiotensin-converting enzyme-1 activity and levels of von Willebrand factor (VWF) and factor VIII could also influence adverse outcomes, notably in group A individuals who express high VWF levels. In conclusion, group O may be associated with a lower risk of SARS-CoV-2 infection and group A may be associated with a higher risk of SARS-CoV-2 infection along with severe disease. However, prospective and mechanistic studies are needed to verify several of the proposed associations. Based on the strength of available studies, there are insufficient data for guiding policy in this regard.

The contribution of provitamin A biofortified cassava to vitamin A intake in Nigerian pre-schoolchildren.

Biofortified yellow cassava has been developed to alleviate vitamin A deficiency. We examined the potential contribution of yellow cassava to total retinol activity equivalent (RAE) intake if replacing white by yellow cassava among pre-school Nigerian children. Dietary intake was assessed as part of a randomised controlled trial. Pre-schoolchildren (n 176) were randomly assigned to receive either white cassava (WC) or yellow cassava (YC) for 17 weeks. Dietary intake assessments were conducted during the intervention and 1 month after, when children had resumed their habitual diet. Differences in RAE intake between groups and time points were compared using a linear mixed model regression analysis. During intervention, median RAE intake was 536 µg/d in the YC group and 301 µg/d in the WC group (P < 0·0001). YC contributed approximately 40 % to total RAE intake. Of the children, 9 % in the YC group and 29 % in the WC group had RAE intake below the Estimated Average Requirement. After intervention, median RAE intake was 300 µg/d and did not differ between intervention groups (P = 0·5). The interaction effect of group and time showed a 37 % decrease in RAE intake in the YC group after the intervention (Exp(ß) = 0·63; 95 % CI 0·56, 0·72). If WC was replaced by YC after intervention, the potential contribution of YC to total RAE intake was estimated to be approximately 32 %. YC increased total RAE intake and showed a substantially lower inadequacy of intake. It is therefore recommended as a good source of provitamin A in cassava-consuming regions.

Metabolic syndrome-related dietary pattern and risk of mortality in kidney transplant recipients.

BACKGROUND AND AIMS: Presence of the metabolic syndrome (MetS) importantly contributes to excess mortality in kidney transplant recipients (KTRs). However, it is unclear which dietary factors drive the adverse role of MetS in KTRs. We aimed to define a dietary pattern that maximally explained the variation in MetS components, and to investigate the association between this MetS-related dietary pattern (MetS-DP) and all-cause mortality in KTRs. METHODS AND RESULTS: We included 429 adult KTRs who had a functioning graft ⩾1 year. A MetS-DP was constructed using habitual dietary intake derived from a 177-item food frequency questionnaire. We used reduced rank regression (RRR), and defined the six components of MetS (waist circumference, systolic blood pressure, diastolic blood pressure, serum triglycerides, HbA1c, and HDL cholesterol) as response variables and 48 food groups as predictor variables. We evaluated the association between the MetS-DP and all-cause mortality using multivariable Cox regression analysis. The MetS-DP was characterized by high intakes of processed meat and desserts, and low intakes of vegetables, tea, rice, fruits, milk, and meat substitutes. During a mean follow-up of 5.3 ± 1.2 years, 63 KTRs (14.7%) died. Compared to the lowest tertile of the Mets-DP score, those with the greatest adherence had a more than 3-fold higher risk of all-cause mortality (hazard ratio [HR] = 3.63; 95% confidence interval [CI], 1.70-7.74, P < 0.001), independent of potential confounders. CONCLUSIONS: We identified a MetS-related dietary pattern which was independently associated with all-cause mortality in KTRs. The association between this dietary pattern and all-cause mortality was mediated by MetS. Clinical trial reg. no. NCT02811835.

Comparison of two nucleic acid amplification technology systems for detection of human immunodeficiency virus, hepatitis B virus, and hepatitis C virus.

Human immunodeficiency virus (HIV) and hepatitis B virus (HBV) are endemic in South Africa while hepatitis C virus (HCV) infection is rare. Two nucleic acid amplification technology platforms, the Procleix Ultrio Elite assay on the Panther instrument (Elite) and the cobas MPX assay on the cobas 6800 or 8800 system (MPX), are used worldwide. In 2015 these were evaluated in South African context. STUDY DESIGN AND METHODS: The sensitivity of HIV, HBV, and HCV was evaluated using reference panels and 2-fold dilutions of 51 positive plasma samples tested in 12 to 24 replicates. The 95% and 50% lower limits of detection (LOD) were estimated by probit analysis and window period (WP) risk days by the Weusten model. Specificity was established by testing 3646 blood donations individually and instrument performance by evaluating all runs. RESULTS: Specificity was 99.94% for MPX and 99.97% for Elite. The following 95% LODs (95% confidence intervals [CIs]) were estimated for MPX and Elite, respectively: HBV, 17.8 (10.9-33.9) and 47.9 (29.1-92.4) cp/mL; HCV, 21.9 (15.3-34.6) and 13.8 (8.9-24.0) cp/mL; and HIV, 8.3 (5.5-14.7) and 10.4 (6.9-18.2) cp/mL. On SA HBV and HIV dilution panels, relative sensitivity (range) of MPX was 3.20 (1.26-6.50) and 1.42 (0.26-2.72) fold higher than Elite. Downtime on cobas 6800 was 26 hours vs 6.6 hours on Panther (P < .001). We estimated infectious WPs for HBV, HCV, and HIV-1 at 13.8, 1.8, and 2.6 days for Elite and 10.3, 2.1, and 2.4 days for MPX. CONCLUSION: Although MPX was significantly more sensitive for HBV, Elite was implemented due to instrument reliability during evaluation.

Trends in platelet distributions from 2008 to 2017: a survey of twelve national and regional blood collectors.

BACKGROUND: This multi-national study evaluated changes in platelet (PLT) unit distributions at 12 national or regional blood collectors over a 10-year period. METHODS: Data on the total number of PLT distributions, the collection method, that is apheresis vs whole blood-derived (WBD), the PLT unit characteristics and post-collection modifications were obtained from 12 national or regional blood collectors from 2008 through 2017. Individual WBD PLT units were converted to apheresis equivalent units (i.e. a dose of PLTs) by dividing by 4, the typical pool size; WBD units that were pooled before distribution were counted as a single dose. RESULTS: Overall at these 12 blood collectors, the total number of PLTs distributed in 2008 was 1 373 200, which rose by 10·2% to 1 513 803 in 2017. The Japanese Red Cross, which distributes only apheresis PLTs, had a 13·4% increase in the number of distributions between the years 2008 and 2017, while the other 11 blood collectors combined demonstrated a 6·8% increase in distributions between these two years. Between the years 2008 and 2017, the changes in the proportion of apheresis, platelet-rich plasma and buffy coat PLT distributions were -29·9%, -70·7% and 80·0%, respectively. CONCLUSION: The number of PLT distributions increased during the 10-year study period despite prophylactic PLT transfusion thresholds having remained fairly consistent over the last decade. Perhaps this increase is in part driven by increased administration of platelets to patients with massive haemorrhage or an increase in stem cell transplantation. The use of buffy coat PLTs is increasing at these collectors.