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

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 in- and out-of-hospital screening for hepatitis C

Because of insidious progression and no significant clinical symptoms at early stage, chronic hepatitis C (CHC) is often diagnosed after the occurrence of cirrhosis and hepatocellular carcinoma. Highly effective and low drug resistance of direct-acting antiviral agents (DAAs) have enabled cure of CHC, encouraging the World Health Organization to propose a global viral hepatitis elimination program. To Date, vaccine for CHC is still under research. Therefore, reducing the source of infection is an important means of eliminating CHC other than cutting off the transmission route, which requires screening, diagnosing and treating as many patients in the population as possible. Hospital-based screening strategy have been found to be cost-effective in the management of CHC screening, as reported both nationally and internationally. Currently, China has issued In-hospital process for viral hepatitis C screening and management in China (Draft) in April, 2021, which provides a standardized implementation process and direction for in-hospital hepatitis C screening and treatment, but still requires medical institution to develop its own management process, taking into account its current situation and learning from domestic and international experience. In addition, screening for CHC outside the hospital among special populations, such as blood donors, pregnant women, homosexuals, intravenous drug users, prisoners, and residents in rural areas with scarce medical care resources, also requires attention and development of targeted and rational screening strategies. In this paper, we analyze and recommend the management of hepatitis C screening from both in-hospital and out-of-hospital perspectives, with the aim of contributing to the formulation of hepatitis C screening strategies.

Transfusion-transmitted arboviruses: Update and systematic review

Background

The detection of the first cases of transfusion-transmitted West Nile virus in 2002 posed a new challenge for transfusion safety. Institutions like the World Health Organization have stated that blood transfusion centers need to know the epidemiology of the different emerging infectious agents and their impact on blood transfusion. The aim of the study is to review the published cases of arbovirus transmission through transfusion of blood or blood components and to analyze their main clinical and epidemiological characteristics.

Material and methods

Systematic literature searches were conducted in MEDLINE, Embase and Scopus. Pairs of review authors selected a variety of scientific publications reporting cases of transfusion-transmitted arboviruses. Main clinical and epidemiological characteristics were reviewed of the cases described. The study protocol was registered in PROSPERO CRD42021270355.

Results

A total of 74 cases of transfusion-transmitted infections were identified from 10 arboviruses: West Nile virus (n = 42), dengue virus (n = 18), Zika virus (n = 3), yellow fever vaccine virus (n = 3), tick-borne encephalitis virus (n = 2), Japanese encephalitis virus (n = 2), Powassan virus (n = 1), St. Louis encephalitis virus (n = 1), Ross River virus (n = 1) and Colorado tick fever virus (n = 1). The blood component most commonly involved was red blood cells (N = 35, 47.3%; 95% confidence interval [CI] 35.9% to 58.7%). In 54.1% (N = 40; 95% CI: 42.7%-65.47%) of the cases, the recipient was immunosuppressed. Transmission resulted in death in 18.9% (N = 14; 95% CI: 10.0%-27.8%) of the recipients. In addition, 18 additional arboviruses were identified with a potential threat to transfusion safety.

Discussion

In the last 20 years, the number of published cases of transfusion-transmitted arboviruses increased notably, implicating new arboviruses. In addition, a significant number of arboviruses that may pose a threat to transfusion safety were detected. In the coming years, it is expected that transmission of arboviruses will continue to expand globally. It is therefore essential that all responsible agencies prepare for this potential threat to transfusion safety.

The transfusion of blood and blood components entails some risks and potential complications, chief among them the transmission of infectious agents. Organizations like the American Association of Blood Banks have warned of the risks posed by emerging and re-emerging viruses for transfusion safety and have classified transmission of several arboviruses as a high or very high risk to the transfusion of blood and blood components. Following recommendations by the World Health Organization (WHO), this study aims to enable safe blood transfusion services, by making available the latest updated information of transfusion-transmitted arboviruses and comprehensive knowledge of the current epidemiology of reported cases.

Research revealed case reports of transfusion transmission of 10 arboviruses, with West Nile virus and dengue virus as the most prevalent. Main clinical characteristics of reported cases were collected, including the type of blood component transfused and the state of immunosuppression of the recipient. Research also revealed 18 additional arboviruses with potential risk of transmission through other direct transmission routes. This systematic review provides an updated overview of the clinical characteristics of reported cases of transfusion-transmitted arboviruses. It is the most complete record published to date that assesses the risk posed by arboviruses to blood transfusion.

Reduction in seroprevalence of viral transfusion-transmitted infections in southwest Nigeria in children with sickle cell disease using an enhanced screening strategy

Blood transfusion is an integral component in the management of children and adults with sickle cell disease (SCD). Concerns about blood safety due to the high risk of bloodborne infections in sub-Saharan Africa limits the application of this cost-effective strategy in the management of individuals with SCD. In a single-centre, retrospective, longitudinal study in southwest Nigeria, we hypothesised that the use of stringent blood donor selection, along with very sensitive enzyme-linked immunosorbent assay (ELISA) screening methods would reduce transfusion-transmitted infections (TTIs). Among 45 002 eligible blood donors at the Lagos University Teaching Hospital in Nigeria, over a 5-year review period (2015-2019), the seroprevalence rate of viral TTIs was 9.83%. The seroprevalence rates for human immunodeficiency, hepatitis B, and hepatitis C viruses were 1.37%, 6.2%, and 2.25% respectively. Among 172 children with SCD, 71% (122/172) on regular blood transfusion and 29% (50/172) who had never been transfused or had less than two transfusions per lifetime, none acquired any TTIs using our enhanced screening approach during the study period. Thus, safe blood transfusion practices can be provided for children with SCD in sub-Saharan Africa with the use of stringent donor selection protocols and fourth-generation ELISA kits for TTI screening.

Nucleic acid testing identifies high prevalence of blood borne viruses among approved blood donors in Mozambique

Background

Although blood transfusion is an intervention that saves lives, it poses significant risks to the blood receivers, including the transmission of bloodborne pathogens. We aimed at determining the prevalence of Human Immunodeficiency Virus (HIV), Hepatitis B virus (HBV), and Hepatitis C virus (HCV) in candidates approved for blood donation, and in samples considered to be negative in reference blood banks in Mozambique.

Methods

A cross-sectional study was performed between November 2014 and October 2015 in Maputo and Beira cities. Demographic information was obtained from all consenting blood donors using a structured questionnaire. Plasma samples were screened for HIVAb/Ag combinations, HBsAg and Anti-HCV. Blood donors considered to be negative by serological testing were re-tested in pools of six plasma samples using nucleic acid testing (NAT).

Results

Most blood donors were male 2,320 (83.4%) with an age range of 18 to 34 years. The overall seroprevalence of HIV, HBV and HCV infections among blood donors approved for donation was 4.6% (127; 95% CI 3.8–5.4), 4.5% (124; 95% CI 3.7–5.3) and 0.4% (11; 95% CI 0.2–0.7), respectively. The overall frequency by NAT of HIV RNA, HBV DNA, and HCV RNA in serologically negative blood donor samples was 2.6 per 1000 blood donors (7; 95% CI 1.1–5.4); 12.5 per 1000 blood donors (33; 95% CI 8.6–17.5) and 2.6 per 1000 blood donors (6; 95% CI 1.0–5.7), respectively.

Conclusion

Our results show high seroprevalence of HIV and HBV infections in blood donors approved for donation, and high frequency of molecular biomarkers of HIV, HBV, and HCV in blood considered to be safe. These results suggest the need for a new blood screening policy in Mozambique, including the use of NAT to detect infectious blood donations during the immunologically negative window.

Assessing the global burden of hemorrhage: The global blood supply, deficits, and potential solutions

There is a critical shortage of blood available for transfusion in many low- and middle-income countries. The consequences of this scarcity are dire, resulting in uncounted morbidity and mortality from trauma, obstetric hemorrhage, and pediatric anemias, among numerous other conditions. The process of collecting blood from a donor to administering it to a patient involves many facets from donor availability to blood processing to blood delivery. Each step faces particular challenges in low- and middle-income countries. Optimizing existing strategies and introducing new approaches will be imperative to ensure a safe and sufficient blood supply worldwide.

The use of the GeeniusTM HIV-1/2 Rapid confirmatory test for the enrolment of patients and blood donors in the WHO Universal Test and Treat Strategy in Cameroon, Africa

BACKGROUND AND OBJECTIVE

In the WHO Universal test and treat strategy, false-positive HIV blood donors and patients may be unnecessarily put under antiretroviral treatment and false-negative subjects may be lost to follow-up. This study assessed the false positivity rate of the Cameroonian national HIV screening testing algorithm and the benefit of a confirmation test in the enrolment of patients and donors in the HIV care programme.

METHODS

We included initial HIV reactive blood donors and patients in a cross-sectional study conducted in two Cameroonian hospitals. Samples were retested according to the Cameroon national algorithm for HIV diagnosis. A positive or discordant sample was retested with the Geenius Bio-Rad HIV 1&2 (Bio-Rad, Marnes-la-Coquette, France) for confirmation. The Geenius HIV-1-positive results with 'poor' profiles were retested for RNA as well as the Geenius indeterminate results.

RESULTS

Of the 356 participants, 190/225 (84·4%) patients and 76/131 (58%) blood donors were declared positive with the national algorithm; 257 participants (96·6%) were confirmed HIV-1-positive. The study revealed that about 34/1000 blood donors and patients are false-positive and unnecessarily put on treatment; 89/1000 blood donors and patients declared discordant could have been included immediately in the HIV care programme if confirmatory testing was performed. The second test of the algorithm had a false-negative rate of 3%. Eleven samples (3·1%) were Geenius poor positive and NAT negative.

CONCLUSION

The universal test and treat strategy may identify and refer more individuals to HIV care if a third rapid confirmatory test is performed for discordant cases.

Prevention of transfusion-transmitted infections. Blood. 2019;133:1854-1864. [PMID: 30808637 DOI: 10.1182/blood-2018-11-833996]

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.

Mannitol-induced gold nanoparticle aggregation for the ligand-free detection of viral particles

Addition of osmolytes causes viruses-coated AuNPs to aggregate and not protein-coated AuNPs. Ligand-free detection of virus was developed without the need for prior knowledge of the specific virus target.

Assessment of rapid diagnostic tests and fourth-generation Enzyme-Linked Immunosorbent Assays in the screening of Human Immunodeficiency and Hepatitis B virus infections among first-time blood donors in Libreville (Gabon)

BACKGROUND

Blood transfusion is a pathway for the transmission of blood-borne pathogens such as human immunodeficiency virus (HIV) and hepatitis B virus (HBV) from donors to recipients in most countries in sub-Saharan Africa, including Gabon. The study aimed to compare the performance of four rapid diagnostic tests (RDTs: Alere DETERMINE, BIOSYNEX Exacto Pro HIV, MEDIFF HIV 1&2, and BIOSYNEX IMMUNOQUICK HBsAg) with results of 4th-generation immunoenzymatic assays COBAS 6000 e601 and EVOLIS BioRad for the detection of HIV and hepatitis B surface antigen (HBsAg) in blood donors in Libreville, Gabon.

METHODS

Reactive and nonreactive blood samples for HIV and HBsAg were selected using fourth-generation ELISA COBAS 6000 e601 and EVOLIS BioRad. The sensitivities of RDTs were calculated using Epi Info version 6.04dfr (CDC, Atlanta, USA).

RESULTS

Sensitivities for the detection of HIV in blood donors were 90.9% for Alere DETERMINE, 81.8% for BIOSYNEX Exacto Pro HIV, and 81.8% for MEDIFF HIV 1&2 Serum/sang Total Cassette compared with COBAS 6000 e601. The sensitivity of Alere DETERMINE compared to the semi-automated ELISA Bio-Rad for HIV detection was 65.6%. The sensitivity of BIOSYNEX IMMUNOQUICK HBsAg compared to ELISA tests for the detection of HBsAg was 78.0%. The specificity of all RDTs for the detection of HIV and HBsAg was 100%.

CONCLUSION

Alere DETERMINE HIV-1/2, MEDIFF HIV 1&2 Serum/sang Total Cassette, BIOSYNEX Exacto Pro HIV, and BIOSYNEX IMMUNOQUICK HBsAg are not recommended for determining whether donors qualify to donate blood because of their low sensitivity for the detection of HIV antibodies and HBsAg in blood donors in Gabon.

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.

New virological tools for screening, diagnosis and monitoring of hepatitis B and C in resource-limited settings

Worldwide, the increasingly dominant model of laboratory testing is the centralised laboratory, in which automation of analytical processes increases, enabling the analysis of large numbers of samples at a relatively low cost. However, this trend does not fulfil the requirements for care of patients with chronic hepatitis B and C in resource-limited settings. Alternative models using point-of-care (POC) tests and dried blood spots (DBSs) are increasingly being considered for viral hepatitis screening, diagnosis and monitoring. POC tests are small devices providing qualitative and/or quantitative determination of viral antibodies and/or antigens. They can use original specimen matrices, such as oral fluid or blood collected from a fingerstick. POC tests are particularly useful for large-scale screening, and to improve access to care in regions where laboratory access is limited. New POC devices that detect and quantify viral nucleic acids are at the developmental stage. DBSs offer the main advantage of enabling storage of desiccated blood that can be easily transported to reference centres, where state-of-the-art molecular and serological diagnostic tests are available. However, standardisation and better automation of DBS handling are needed. Herein, we review alternatives to classical hepatitis B and C virological tests, examining POC tests and DBSs, as well as alternatives to nucleic acid testing. Innovations in testing approaches resulting from the availability of these new assays are also discussed.

Analytical performances of simultaneous detection of HIV-1, HIV-2 and hepatitis C- specific antibodies and hepatitis B surface antigen (HBsAg) by multiplex immunochromatographic rapid test with serum samples: A cross-sectional study

BACKGROUND

The HIV/HCV/HBsAg Triplex consists in manually performed, visually interpreted, lateral flow, immunochromatographic rapid diagnostic test simultaneously detecting in 15min human immunodeficiency virus (HIV)-1 and HIV-2 and hepatitis C virus (HCV)- specific antibodies (Ab) (IgG and IgM) and hepatitis B virus (HBV) surface antigen (HBsAg) in serum, plasma and whole blood.

METHODS

A hospital-based cross-sectional study was conducted on a prospective panel of serum samples from adult inpatients included from routine analysis irrespectively of age and sex, including 250 sera positive for HIV-1-specific Ab, 250 for HCV-specific Ab, 250 for HBsAg and 250 sera negative for HIV- and HCV- Ab and HBsAg, and from 110 HIV-2-infected patients living in Ivory Coast, according to the results obtained by the reference chemiluminiscent microparticle immunoassay (CMIA) Abbott Architect i2000SR analyzer (Abbott Diagnostic, Chicago, IL, USA). Among HCV-seropositive sera, 187 were positive for HCV RNA (chronic infection), whereas 63 were negative (resolved infection), respectively. Serum samples were further tested blindly by HIV/HCV/HBsAg Triplex according to manufacturers' recommendations.

RESULTS

HIV/HCV/HBsAg Triplex showed very high sensitivity and specificity, as well as excellent concordance with CMIA Abbott results, as shown in the Table. Lower sensitivity was observed only in individuals who had cleared their HCV infection (presence of HCV-specific Ab in absence of HCV RNA). The mean lower limit of HBsAg detection was 2.38±0.63 IU/ml. Erythrocytes-spiked serum samples gave similar results than serum samples.

CONCLUSIONS

Advantages of HIV/HCV/HBsAg Triplex for HIV-1, HIV-2, HCV and HBV include the requirement for less overall specimen volume, fewer finger-sticks if capillary whole blood is used, cost savings through lower cost per virus tested, improved patient flow with results for multiple viruses available at the same time, overall service delivery efficiencies with less time required per infected patient; and patient benefits from fewer visits and lower cost associated with each clinic attendance. The screening of chronic HIV, HCV and HBV by multiplex HIV-1/HIV-2/HCV/HBsAg Triplex may improve the "cascade of screening" and quite possibly linkage-to-care with reduced cost.