A pilot external quality assurance study of transfusion screening for HIV, HCV and HBsAG in 12 African countries

Blood Banking Capacity in Low-and Middle-Income Countries: Covid-19 Convalescent Plasma in Context

Blood transfusion capacity in low- and middle-income countries (LMICs), encompassing both the safety and adequacy of the blood supply, is limited. The challenges facing blood banks in LMICs include regulatory oversight, blood donor selection, collection procedures, laboratory testing, and post-transfusion surveillance. A high proportion of LMICs are unable to fully meet clinical demands for blood products, and many do not meet even the minimum threshold of collection (10 units per 1000 population). Suboptimal clinical transfusion practices, in large part due to a lack of training in transfusion medicine, contribute to blood wastage. During the COVID-19 pandemic, high- and LMICs alike experienced blood shortages, in large part due to quarantine and containment measures that impeded donor mobility. COVID-19 convalescent plasma (CCP) was particularly appealing for the treatment of patients with COVID-19 in LMICs, as it is a relatively inexpensive intervention and makes use of the existing blood collection infrastructure. Nonetheless, the challenges of using CCP in LMICs need to be contextualized among broad concerns surrounding blood safety and availability. Specifically, reliance on first time, family replacement and paid donors, coupled with deficient infectious disease testing and quality oversight, increase the risk of transfusion transmitted infections from CCP in LMICs. Furthermore, many LMICs are unable to meet general transfusion needs; therefore, CCP collection also risked exacerbation of pervasive blood shortages.

Survey of blood collection and transfusion practices among institutions in Africa

INTRODUCTION

Dramatic improvements in blood transfusion have occurred during the last two decades. Transfusion medicine services and practices in Africa remain underexplored.

METHODS

A survey of blood bank/transfusion medicine (BBTM) practices, available blood products, blood product source(s), pre-transfusion testing, and blood donor infectious disease testing methodologies across Africa was performed using the American Society for Clinical Pathology (ASCP) listserv. Survey recipients included hospital-based laboratories/blood banks, national transfusion medicine services, and free-standing laboratories (collectively referred to as institutions).

RESULTS

Responses from a total of 81 institutions across 22 countries were analyzed. All 81 institutions provide at least one type of blood product-whole blood, red blood cells (RBCs), platelets, plasma, and cryoprecipitate, with whole blood (90.1%, 73 of 81) and RBCs (79.0%, 64 of 81) most common, while cryoprecipitate is least common (12.4%, 10 of 81). Only five countries had a responding institution that provides all types of products. Among institutions that collect blood onsite, the most common sources of blood products are patients' family members (94.1%, 48 of 51) and pre-screened on-demand volunteer donors (82.4%, 42 of 51). The most commonly screened infectious agents are HIV and hepatitis B virus (both 81.5%), while 70.4% (57 of 81) test for hepatitis C virus (HCV) and Treponema pallidum.

DISCUSSION

This study highlights significant variability and restrictions in blood product availability, pre-transfusion testing, and blood donor infectious disease testing across Africa. Further studies are needed to ascertain barriers to improving blood donor availability, blood product safety, and infectious disease testing.

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.

Neurosurgical Patients’ Experiences and Surgical Outcomes Among Single Tertiary Hospitals in Ethiopia and the United States

Background

In 2020, we published findings on reported outcomes of anterior cervical decompression and fusion surgery among neurosurgeons in Africa and North America. We found more similarities in outcomes than expected, however, differences still existed. Most notable was the length of stay of patients postoperatively in Africa compared to North America. We sought to examine the neurosurgical practices more closely at a single hospital in Ethiopia and compare it to our own institution, the University of Missouri in Columbia (UMC).

Methods

Two authors spent one week at Aabet Hospital (AH) in Ethiopia. Throughout the week, one author rotated in the clinic and OR gathering the information. Data collection for patients at UMC was collected through retrospective chart review over one week.

Results

A total of eight elective surgeries and four emergency procedures occurred at AH and 18 clinic patients were included in the study. The intraoperative data was collected during the elective procedures at AH. At UMC there were 99 clinic patients, and 29 elective surgeries and one emergency procedure were performed. Procedures at both institutions included cranial, spinal, vascular, and implantable/other cases. Distance travelled by patients to UMC was an average of 57 miles compared to 85 miles at AH. The median pre-op and post-op stays at AH were 2.5 and 6 days compared to 0.2 and 2.1 at UMC, respectively. Blood loss was greater at AH with a median blood loss of 175 mL. Median blood loss at UMC was 50 mL.

Conclusion

We found notable differences among neurosurgical practice and patient demographics at AH compared to UMC. This information will serve as the cornerstone for gathering more information about neurosurgical practice in Ethiopia where electronic medical records are unavailable.

Challenges in transfusion-transmitted infection screening in Sub-Saharan Africa

In Sub-Saharan Africa, high clinical demand for transfusion faces endemic bloodborne infections and limited resources. Blood screening for transfusion-transmitted bloodborne pathogens is the cornerstone of blood safety. Although there have been substantial improvements over the years, challenges in transfusion-transmitted infection screening that have been identified repeatedly long ago still need to be addressed. Affordability and sustainability of state-of-the-art quality assessed serological and molecular assays, and associated confirmation strategies remain of real concern. In addition, limited resources and infrastructures hamper the development of adequate facilities, quality management, and staff qualification, and exacerbate shortage of reagents and equipment maintenance. It is also important to maintain effort in constituting pools of repeat voluntary non-remunerated donors. Alternative strategies for blood screening that take into account local circumstances might be desirable but they should rely on appropriate field evaluation and careful economic assessment rather than dogma established from high-resource settings.

New HIV infections from blood transfusions averted in 28 countries supported by PEPFAR blood safety programs, 2004-2015

BACKGROUND

To quantify the impact of the US President's Emergency Plan for AIDS Relief (PEPFAR) on the risk of HIV transmission through infected blood donations in countries supported by PEPFAR blood safety programs.

METHODS

Data reported to the World Health Organization Global Database on Blood Safety were analyzed from 28 countries in sub-Saharan Africa (SSA), Asia, and the Caribbean during 2004-2015. We used the Goals model of Spectrum Spectrum System Software, version 5.53, to perform the modeling, assuming laboratory quality for HIV testing had 91.9% sensitivity and 97.7% specificity irrespective of testing method based on results of two external quality assurance and proficiency testing studies of transfusion screening for HIV in SSA blood centers. We calculated the number of new HIV infections from the number of transfusions and the prevalence of HIV infection acquired from blood transfusions with infected blood donations. We determined the impact of laboratory testing programs by estimating the number of new HIV infections averted since PEPFAR implementation.

RESULTS

Assuming that HIV testing would not be performed in any of these countries without PEPFAR funding, the number of new HIV infections acquired from blood transfusions averted by laboratory testing increased over time in all 28 countries. The total number of HIV infections averted was estimated at 229 278 out of 20 428 373 blood transfusions during 2004-2015.

CONCLUSION

Our mathematical modeling suggests a positive impact achieved over 12 years of PEPFAR support for blood safety. Standardized HIV testing of donated blood has reduced the risk of HIV transmission through blood transfusions in SSA, Asia, and the Caribbean.

Frequency of Hepatitis B, C and HIV Infections among Transfusion-Dependent Beta Thalassemia Patients in Dhaka

Transfusion transmitted infections have remained a major deterrent to public health, particularly among the patients with transfusion-dependent Beta thalassemia in developing countries. Although proper donor selection through adoption of WHO-advised infection panel has lowered the rate of infections, the multi-transfused patients are not free of risk. In this study, we screened 148 transfusion-dependent Beta thalassemia patients to determine the frequency of Hepatitis C Virus (HCV), Hepatitis B Virus (HBV) and Human Immunodeficiency Virus (HIV) using the ELISA method. Among them, infected cases with HCV, HBV and HIV were 13.51%, 3.37% and 0%, respectively. Moreover, 2% of the patients were found to be co-infected with both HBV and HCV. The percentage of infections in the patients with frequent transfusion interval (≤30 days) was significantly higher (p < 0.0005) than that in the patients with less frequent transfusion intervals (>30 days). Immunochromatography (ICT)-based rapid test kits are usually used to screen and confirm these infections in the blood of the patients. However, ICT-based tests are not sensitive enough to detect the infections. So, a combination of both Nucleic Acid testing (NAT) and serological testing are suggested to significantly reduce the risk of viral infections during blood transfusion.

Inactivation of a broad spectrum of viruses and parasites by photochemical treatment of plasma and platelets using amotosalen and ultraviolet A light

BACKGROUND

The INTERCEPT Blood System pathogen reduction technology (PRT), which uses amotosalen and ultraviolet A light treatment (amotosalen/UV-PRT), inactivates pathogens in plasma and platelet components (PCs). This review summarizes data describing the inactivation efficacy of amotosalen/UVA-PRT for a broad spectrum of viruses and parasites.

METHODS

Twenty-five enveloped viruses, six nonenveloped viruses (NEVs), and four parasites species were evaluated for sensitivity to amotosalen/UVA-PRT. Pathogens were spiked into plasma and PC at high titers. Samples were collected before and after PRT and assessed for infectivity with cell cultures or animal models. Log reduction factors (LRFs) were defined as the difference in infectious titers before and after amotosalen/UV-PRT.

RESULTS

LRFs of ≥4.0 log were reported for 19 pathogens in plasma (range, ≥4.0 to ≥7.6), 28 pathogens in PC in platelet additive solution (PC-PAS; ≥4.1-≥7.8), and 14 pathogens in PC in 100% plasma (PC-100%; (≥4.3->8.4). Twenty-five enveloped viruses and two NEVs were sensitive to amotosalen/UV-PRT; LRF ranged from >2.9 to ≥7.6 in plasma, 2.4 or greater to greater than 6.9 in PC-PAS and >3.5 to >6.5 in PC-100%. Infectious titers for four parasites were reduced by >4.0 log in all PC and plasma (≥4.9 to >8.4).

CONCLUSION

Amotosalen/UVA-PRT demonstrated effective infectious titer reduction for a broad spectrum of viruses and parasites. This confirms the capacity of this system to reduce the risk of viral and parasitic transfusion-transmitted infections by plasma and PCs in various geographies.

High rate of hepatitis C virus and human immunodeficiency virus false-positive results in serologic screening in sub-Saharan Africa: adverse impact on the blood supply

BACKGROUND

False positivity in blood screening may cause unnecessary deferral of healthy donors and exacerbate blood shortages. An international multicenter study was conducted to estimate the frequency of HCV and HIV false seropositivity in seven African countries (Burundi, Cameroon, Democratic Republic of Congo, Madagascar, Mali, Mauritania, and Niger).

STUDY DESIGN AND METHODS

Blood donations were tested for hepatitis C virus (HCV) and human immunodeficiency virus (HIV) with rapid detection tests (RDTs), third-generation enzyme immunoassays (EIAs), or fourth-generation EIAs. HCV (456/16,613 [2.74%]) and HIV (249/16,675 [1.49%]) reactive samples were then confirmed with antigen/antibody assays, immunoblots, and nucleic acid testing. Partial viral sequences were analyzed when possible.

RESULTS

The HCV reactivity rate with RDTs was significantly lower than with EIAs (0.55% vs. 3.52%; p < 0.0001). The HIV reactivity rate with RDTs was lower than with third-generation EIAs (1.02% vs. 2.38%; p < 0.0001) but similar to a fourth-generation assay (1.09%). Only 16.0% (57/357) and 21.5% (38/177) of HCV and HIV initial reactive samples, respectively, were repeatedly reactive. HCV and HIV infections were confirmed in 13.2% and 13.7%, respectively, of repeated reactive donations. The predominant HCV genotype 2 and 4 strains in West and Central Africa showed high genetic variability. HIV-1 subtype CRF02_AG was most prevalent.

CONCLUSION

High rates (>80%) of unconfirmed anti-HCV and anti-HIV reactivity observed in several sub-Saharan countries highlights the need for better testing and confirmatory strategies for donors screening in Africa. Without confirmatory testing, HCV and HIV prevalence in African blood donors has probably been overestimated.

Experience of Indian association of medical microbiology external quality assurance scheme centre, New Delhi: Challenges and quality assessment of clinical microbiology laboratories

Introduction

EQAS program at New Delhi under IAMM was started in January 2014 across North and North east regions of India with 217 participants, which grew up to 540 by 2018.

Materials and Methods

In 2014, 4 analytes per year were sent for 3 exercises, i.e. smear culture and serology. 2018 onwards PT analytes were increased from 4 to 12 and comparative performance of techniques analysed.

Results

Out of the 22 smears sent for gram staining, ZN staining, Kinyoun staining and Albert staining, completely correct results ranged between 29.55% - 79.9%, 94.3% - 99.2%, 35.5% & 93.8%, respectively. Correct results for culture isolate identification & susceptibility testing and serology exercises varied between 70 & 92.4% and 73.1 & 98.59%, respectively. In the year 2018, 470 responses were received for bacterial culture identification & antibiotic susceptibility testing out of which manual and automated systems were used by 54% & 46% and 52.5% & 47.5% participants, respectively. Techniques used in BBV assays for HBsAg, HCV & HIV found all methods like ELISA, ELFA, CLIA and Card Test performing similarly. The major challenges in running the EQA program included requirement of large amount of specimens for PT item preparation, stability in hot and humid conditions and timely delivery of PT challenges in remote parts of the country.

Conclusion

A large number of the participating laboratories (77%) had an overall score of >80% for all exercises, demonstrating acceptable baseline performance of EQAS registered laboratories. However, continued EQAS participation could further improve the quality of results.

Prevention of transfusion-transmitted infections

Since the 1970s, introduction of serological assays targeting virus-specific antibodies and antigens has been effective in identifying blood donations infected with the classic transfusion-transmitted infectious agents (TTIs; hepatitis B virus [HBV], HIV, human T-cell lymphotropic virus types I and II, hepatitis C virus [HCV]). Subsequently, progressive implementation of nucleic acid-amplification technology (NAT) screening for HIV, HCV, and HBV has reduced the residual risk of infectious-window-period donations, such that per unit risks are <1 in 1 000 000 in the United States, other high-income countries, and in high-incidence regions performing NAT. NAT screening has emerged as the preferred option for detection of newer TTIs including West Nile virus, Zika virus (ZIKV), and Babesia microti Although there is continual need to monitor current risks due to established TTI, ongoing challenges in blood safety relate primarily to surveillance for emerging agents coupled with development of rapid response mechanisms when such agents are identified. Recent progress in development and implementation of pathogen-reduction technologies (PRTs) provide the opportunity for proactive rather than reactive response to blood-safety threats. Risk-based decision-making tools and cost-effectiveness models have proved useful to quantify infectious risks and place new interventions in context. However, as evidenced by the 2015 to 2017 ZIKV pandemic, a level of tolerable risk has yet to be defined in such a way that conflicting factors (eg, theoretical recipient risk, blood availability, cost, and commercial interests) can be reconciled. A unified approach to TTIs is needed, whereby novel tests and PRTs replace, rather than add to, existing interventions, thereby ameliorating cost and logistical burden to blood centers and hospitals.

Blood transfusion safety in sub-Saharan Africa: A literature review of changes and challenges in the 21st century

BACKGROUND

Access to a safe, adequate blood supply has proven challenging in sub-Saharan Africa, where systemic deficiencies spanning policy, collections, testing, and posttransfusion surveillance have long been recognized. Progress in transfusion safety in the early 2000s was in large part due to intervention by the World Health Organization and other foreign governmental bodies, coupled with an influx of external funding.

STUDY DESIGN AND METHODS

A review of the literature was conducted to identify articles pertaining to blood safety in sub-Saharan Africa from January 2009 to March 2018. The search was directed toward addressing the major elements of the blood safety chain, in the countries comprising the World Health Organization African region. Of 1380 articles, 531 met inclusion criteria and 136 articles were reviewed.

RESULTS

External support has been associated with increased recruitment of voluntary donors and expanded testing for the major transfusion-transmitted infections (TTIs). However, the rates of TTIs among donors remain high. Regional education and training initiatives have been implemented, and a tiered accreditation process has been adopted. However, a general decline in funding for transfusion safety (2009 onwards) has strained the ability to maintain or improve transfusion-related services. Critical areas of need include data collection and dissemination, epidemiological surveillance for TTIs, donor recruitment, quality assurance and oversight (notably laboratory testing), and hemovigilance.

CONCLUSION

Diminishing external support has been challenging for regional transfusion services. Critical areas of deficiency in regional blood transfusion safety remain. Nonetheless, substantive gains in education, training, and accreditation suggest durable gains in regional capacity.

Hepatitis virus (HCV) diagnosis and access to treatment in a UK cohort

Background

As direct acting antiviral (DAA) therapy is progressively rolled out for patients with hepatitis C virus (HCV) infection, careful scrutiny of HCV epidemiology, diagnostic testing, and access to care is crucial to underpin improvements in delivery of treatment, with the ultimate goal of elimination.

Methods

We retrospectively studied microbiology records from a large UK teaching hospital in order to compare the performance of HCV screening and diagnostic tests (antibody, antigen and HCV RNA detection). Having described a local cohort of adults with active HCV infection, we investigated the proportion who attended hospital appointments, were prescribed direct acting antiviral (DAA) therapy, and cleared HCV RNA following treatment.

Results

Over a total time period of 33 months between 2013 and 2016, we tested 38,509 individuals for HCV infection and confirmed a new diagnosis of active HCV infection (HCV-Ag + and/or HCV RNA+) in 353 (positive rate 0.9%). Our in-house HCV-Ab screening test had a positive predictive value of 87% compared to repeat HCV-Ab testing in a reference laboratory, highlighting the potential for false positives to arise using this test. HCV-Ag had 100% positive predictive value compared to detection of HCV RNA. There was a strong correlation between quantitative HCV-Ag and HCV RNA viral load (p < 0.0001). Among the cases of infection, genotype-1 and genotype-3 predominated, the median age was 37 years, 84% were male, and 36% were in prison. Hepatology review was provided in 39%, and 22% received treatment. Among those who received DAA therapy with 12 weeks of follow-up, 93% achieved a sustained virologic response (SVR₁₂).

Conclusions

HCV-Ag performs well as a diagnostic test compared to PCR for HCV RNA. Active HCV infection is over-represented among men and in the prison population. DAA therapy is successful in those who receive it, but a minority of patients with a diagnosis of HCV infection access clinical care. Enhanced efforts are required to provide linkage to clinical care within high risk populations.

Addressing gaps in international blood availability and transfusion safety in low- and middle-income countries: a NHLBI workshop

In April 2017, a workshop sponsored by the National Heart, Lung, and Blood Institute, Division of Blood Diseases and Resources, and the Center for Translation Research and Implementation Science was held to discuss blood availability and transfusion safety in low- and middle-income countries (LMICs). The purpose of the workshop was to identify research opportunities for implementation science (IS) to improve the availability of safe blood and blood components and transfusion practices in LMICs. IS describes the late stages of the translational research spectrum and studies optimal and sustainable strategies to deliver proven-effective interventions. Regional working groups were formed to focus on opportunities and challenges in East Africa, Central/West Africa, Middle East and North Africa, Latin America and the Caribbean, Southeast Asia, Western Pacific Asia, Eastern Europe, and Central Asia. The need for an "adequate supply of safe blood" emerged as the major overriding theme. Among the regional working groups, common cross-cutting themes were evident. The majority of research questions, priorities, and strategies fell into the categories of blood availability, blood transfusion safety, appropriate use of blood, quality systems, health economics and budgeting, and training and education in IS. The workshop also brought into focus inadequate country-level data that can be used as the basis for IS initiatives. A mixed approach of needs assessment and targeted interventions with sufficient evidence base to move toward sustainment is an appropriate next step for blood availability and transfusion safety research in LMICs.

Hepatitis B Virus Blood Screening: Need for Reappraisal of Blood Safety Measures?

Over the past decades, the risk of HBV transfusion–transmission has been steadily reduced through the recruitment of volunteer donors, the selection of donors based on risk-behavior evaluation, the development of increasingly more sensitive hepatitis B antigen (HBsAg) assays, the use of hepatitis B core antibody (anti-HBc) screening in some low-endemic countries, and the recent implementation of HBV nucleic acid testing (NAT). Despite this accumulation of blood safety measures, the desirable zero risk goal has yet to be achieved. The residual risk of HBV transfusion–transmission appears associated with the preseroconversion window period and occult HBV infection characterized by the absence of detectable HBsAg and extremely low levels of HBV DNA. Infected donations tested false-negative with serology and/or NAT still persist and derived blood components were shown to transmit the virus, although rarely. Questions regarding the apparent redundancy of some safety measures prompted debates on how to reduce the cost of HBV blood screening. In particular, accumulating data strongly suggests that HBsAg testing may add little, if any HBV risk reduction value when HBV NAT and anti-HBc screening also apply. Absence or minimal acceptable infectious risk needs to be assessed before considering discontinuing HBsAg. Nevertheless, HBsAg remains essential in high-endemic settings where anti-HBc testing cannot be implemented without compromising blood availability. HBV screening strategy should be decided according to local epidemiology, estimate of the infectious risk, and resources.

Pathogen reduction and blood transfusion safety in Africa: strengths, limitations and challenges of implementation in low-resource settings

Transfusion-transmitted infection risk remains an enduring challenge to blood safety in Africa. A high background incidence and prevalence of the major transfusion-transmitted infections (TTIs), dependence on high-risk donors to meet demand, suboptimal testing and quality assurance collectively contribute to the increased risk. With few exceptions, donor testing is confined to serological evaluation of human immunodeficiency virus (HIV), hepatitis B and C (HBV and HCV) and syphilis. Barriers to implementation of broader molecular methods include cost, limited infrastructure and lack of technical expertise. Pathogen reduction (PR), a term used to describe a variety of methods (e.g. solvent detergent treatment or photochemical activation) that may be applied to blood following collection, offers the means to diminish the infectious potential of multiple pathogens simultaneously. This is effective against different classes of pathogen, including the major TTIs where laboratory screening is already implemented (e.g. HIV, HBV and HCV) as well pathogens that are widely endemic yet remain unaddressed (e.g. malaria, bacterial contamination). We sought to review the available and emerging PR techniques and their potential application to resource-constrained parts of Africa, focusing on the advantages and disadvantages of such technologies. PR has been slow to be adopted even in high-income countries, primarily given the high costs of use. Logistical considerations, particularly in low-resourced parts of Africa, also raise concerns about practicality. Nonetheless, PR offers a rational, innovative strategy to contend with TTIs; technologies in development may well present a viable complement or even alternative to targeted screening in the future.

Aiming at the Global Elimination of Viral Hepatitis: Challenges Along the Care Continuum

A recent international workshop, organized by the authors, analyzed the obstacles facing the ambitious goal of eliminating viral hepatitis globally. We identified several policy areas critical to reaching elimination targets. These include providing hepatitis B birth-dose vaccination to all infants within 24 hours of birth, preventing the transmission of blood-borne viruses through the expansion of national hemovigilance schemes, implementing the lessons learned from the HIV epidemic regarding safe medical practices to eliminate iatrogenic infection, adopting point-of-care testing to improve coverage of diagnosis, and providing free or affordable hepatitis C treatment to all. We introduce Egypt as a case study for rapid testing and treatment scale-up: this country offers valuable insights to policy makers internationally, not only regarding how hepatitis C interventions can be expeditiously scaled-up, but also as a guide for how to tackle the problems encountered with such ambitious testing and treatment programs.

The contribution of unsafe blood transfusion to human immunodeficiency virus incidence in sub-Saharan Africa: reexamination of the 5% to 10% convention

BACKGROUND

Historical estimates have attributed 5% to 10% of new human immunodeficiency virus (HIV) infections in sub-Saharan Africa (SSA) to unsafe blood transfusions. Although frequently cited, the validity of this statistic is uncertain or outdated. Recent estimates suggest blood transfusion's contribution to new HIV infections in the region may be much lower.

STUDY DESIGN AND METHODS

We searched the peer-reviewed and gray literature for quantitative estimates of the specific contribution of unsafe blood transfusion to the proportion of new HIV infections occurring in SSA. The sources and methods used to generate attribution estimates were evaluated against published country-specific HIV prevalence data.

RESULTS

Despite multiple secondary citations, a primary published source attributing 5% to 10% of new HIV infections to blood transfusions in SSA could not be established for the current era. The United Nations Programme on HIV and AIDS (UNAIDS) modes of transmission (MOT) reports representing 15 countries suggest that between 0 and 1.1% of new HIV infections per year (median, 0.2% or approx. two out of 1000 new infections each year) may be attributable to blood transfusions.

CONCLUSION

Recent modeled estimates suggest that blood transfusions account for a very low proportion of new HIV infections in SSA, likely an order of magnitude lower than 5% to 10%. Direct quantification of risk is challenging given the paucity of data on the variables that impact transfusion-associated HIV. Specifically, data on HIV incidence in blood donors, blood bank laboratory test performance, and posttransfusion surveillance are lacking. Findings suggest an urgent need for improved surveillance and modeling of transfusion-associated HIV transmission in the region.

Progress Toward Strengthening National Blood Transfusion Services - 14 Countries, 2011-2014

Blood transfusion is a life-saving medical intervention; however, challenges to the recruitment of voluntary, unpaid or otherwise nonremunerated whole blood donors and insufficient funding of national blood services and programs have created obstacles to collecting adequate supplies of safe blood in developing countries (1). Since 2004, the U.S. President's Emergency Plan for AIDS Relief (PEPFAR) has provided approximately $437 million in bilateral financial support to strengthen national blood transfusion services in 14 countries in sub-Saharan Africa and the Caribbean* that have high prevalence rates of human immunodeficiency virus (HIV) infections. CDC analyzed routinely collected surveillance data on annual blood collections and HIV prevalence among donated blood units for 2011-2014. This report updates previous CDC reports (2,3) on progress made by these 14 PEPFAR-supported countries in blood safety, summarizes challenges facing countries as they strive to meet World Health Organization (WHO) targets, and documents progress toward achieving the WHO target of 100% voluntary, nonremunerated blood donors by 2020 (4). During 2011-2014, overall blood collections among the 14 countries increased by 19%; countries with 100% voluntary, nonremunerated blood donations remained stable at eight, and, despite high national HIV prevalence rates, 12 of 14 countries reported an overall decrease in donated blood units that tested positive for HIV. Achieving safe and adequate national blood supplies remains a public health priority for WHO and countries worldwide. Continued success in improving blood safety and achieving WHO targets for blood quality and adequacy will depend on national government commitments to national blood transfusion services or blood programs through increased public financing and diversified funding mechanisms for transfusion-related activities.

Screening for transfusion transmissible infections using rapid diagnostic tests in Africa: a potential hazard to blood safety?

Rapid diagnostic tests (RDTs) are routinely used in African blood centres. We analysed data from two cross-sectional studies representing 95 blood centres in 29 African countries. Standardized panels of sera containing varying concentrations of anti-human immunodeficiency virus (HIV) antibodies (Ab), hepatitis B virus antigen (HBsAg) and antihepatitis C virus (HCV) Ab were screened using routine operational testing procedures at the centres. Sensitivity of detection using RDTs was high for HIV Ab-positive samples, but low for intermediately HBsAg (51·5%) and HCV Ab (40·6%)-positive samples. These findings suggest that current RDT use in Africa could pose a hazard to blood safety.

All-in-one dry-reagent time-resolved immunofluorometric assay for the rapid detection of HIV-1 and -2 infections

An all-in-one (AIO) dry-reagent time-resolved fluorometric immunoassay that requires minimal liquid handling was developed for the detection of anti-HIV-1 and -2 antibodies. To prepare the AIO wells, in vivo biotinylated capture antigens (r-Bio-HIV-1env and r-Bio-HIV-2env) were immobilized on streptavidin-coated microtitration wells and Eu(III) chelate labelled non-biotinylated tracer antigens [r-HIV-1env-Eu(III) and r-HIV-2env-Eu(III)] were dried in stable form in the same wells. The HIV AIO assay was evaluated with serum/plasma samples (n=148) from in-house and commercial panels at two different incubation times of 15 min and 1h. The overall sensitivity of the AIO assay was 98.6% and specificity was 100% for both the incubation times. The AIO assay can accept whole blood matrix. This assay is envisioned to fill the gap between the rapid point-of-care assays and traditional enzyme immunoassays (EIA) in terms of complexity and turnaround time, without compromising the performance.

The use of rapid diagnostic tests for transfusion infectious screening in Africa: a literature review

Infectious risk associated with blood transfusion remains a major public health challenge in Africa, where prevalence rates of the major transfusion-transmissible infections (ie, hepatitis B, hepatitis C, human immunodeficiency virus, and syphilis) are among the highest in the world. Resource-limited blood services often operate with minimal predonation screening safeguards, prompting exclusive reliance on laboratory testing to mitigate infectious risk. Transfusion screening with rapid diagnostic tests (RDTs) has been adopted in areas that lack the capacity to support the routine use of more sophisticated technologies. However, uncertainty surrounding the performance of some RDTs in the field has spurred debate regarding their application to blood donation screening. Our review of the literature identified 17 studies that evaluated RDTs for the infectious screening of blood donors in Africa. The review highlights the variable performance of available RDTs and the importance of their use in a quality-assured manner. Deficiencies in performance observed with some RDTs underscore the need to validate test kits prior to use under field conditions with locally acquired samples. Suboptimal sensitivities of some available tests, specifically hepatitis B virus rapid assays, question their suitability in single-test algorithms, particularly in high-prevalence regions. Although RDTs have limitations, many of which can be addressed through improved training and quality systems, they are frequently the only viable option for infectious screening in resource-poor African countries. Therefore, additional studies and specific guidelines regarding the use of RDTs in the context of blood safety are needed.