Reducing the risk of transfusion-transmissible viral infection through blood donor selection: the Australian experience 2000 through 2006

Notification and follow-up of blood donors reactive for transfusion-transmitted infections: A narrative review of the literature from India

BACKGROUND AND OBJECTIVES

Notifying blood donors of their reactive status for transfusion-transmitted infections (TTIs) plays a vital role in enabling early diagnosis and management while also preventing these donors from making future donation and transmission of the infectious agent. Given the limited data on donor notification processes in India, a narrative review was conducted to assess the existing notification process and identify areas requiring enhancement.

MATERIALS AND METHODS

We conducted literature searches using PubMed, Google Scholar and Scopus, employing various keywords. The review included data on the year of the study, study design, donor numbers, TTI screening methods, sero-reactive donor confirmation, notification frequency and methods, donor responses, post-test counselling and risk factor assessment.

RESULTS

Out of the 29 identified articles, 16 studies were included in the analysis. Repeat testing for initially reactive results was conducted in nine studies for 24.3% reactive donors. Phone calls were the primary notification method in most studies (8; 50%), with letters sent in cases of no response. Only 12 studies provided data on notified donors, revealing a notification rate of 71.2%. Of all initially reactive donors, 33.3% sought post-test counselling. Data from six studies indicated that 74.3% of responsive donors had identifiable TTI risk factors.

CONCLUSION

Our review revealed significant variability in the notification processes across different studies. To enhance the management of TTI-reactive donor notifications and responses, we recommend the establishment of universal protocols encompassing pre-donation counselling, repeat/confirmatory testing, notification methods and comprehensive follow-up and treatment.

Seroprevalence and Trend of HBV, HCV, and HIV Infections among Blood Donors of Fars Province, Iran (2006-2018)

Background

Blood transfusion is a life-saving procedure; millions of lives are saved each year. However, blood transfusions are associated with certain risks that can lead to adverse consequences. This study aimed to survey the prevalence and trend of hepatitis B virus (HBV), hepatitis C virus (HCV), and Human immunodeficiency virus (HIV) among blood donors of Fars province, Iran (2006–2018).

Methods

This retrospective cross-sectional study was conducted by reviewing the records of the blood transfusion organization of Fars province. A total of 1952478 blood units were screened for transfusion-transmitted infections (TTIs). Then, data were entered into SPSS software (Negare. version 25). Chi-square test was used to compare the sof TTIs among blood donors. Chisquare test for trend was used to analyze the variations in trends of TTIs during this period. Finally, p-values less than 0.05 were considered statistically significant. GraphPad Prism software was used for the depiction of the graphs.

Results

Among the 1952478 blood donations within the 13-years, 4479(0.229 %) of donors were HBsAg, HCV Ab, and HIV Ag-Ab positive. The seroprevalence of HBV, HCV, and HIV was 2684(0.137%), 1703(0.087 %), and 92(0.0047%), respectively.

Conclusion

The current study showed that the overall prevalence of TTIs among blood donors was low and had a descending trend over the years of study.

Effect of donor type on volume of blood transfusions required after allogeneic hematopoietic cell transplantation

We reviewed blood product use in 729 consecutive allogeneic hematopoietic cell transplantation (allo-HCT) recipients at our center to assess the volume of red blood cells (RBCs) and platelets required after allo-HCT. The median number of bags required by day 30 was 4 for RBCs (range 0-22) and 9.5 for platelets (0-53). Multivariate analysis showed that related peripheral blood stem cell transplantation (PBSCT) required a significantly lower RBC transfusion volume by day 30 compared to unrelated bone marrow transplantation (UBMT). PBSCT from haplo-identical related donors and cord blood transplantation (CBT) required a significantly greater RBC transfusion volume. For platelet transfusion, related and unrelated PBSCT required a significantly lower volume than UBMT, and CBT a greater volume. Other factors independently associated with greater RBC transfusion volume were male sex, disease status other than complete remission, and major ABO mismatch. For platelet transfusion, these were male sex, disease status, and HCT-specific comorbidity index of 1. Although the burden of blood transfusions may not be the most important factor when choosing a donor type, our findings may provide a foundation for nationwide strategies to prepare blood products and inform aspects of national healthcare expenditures.

Efficacy of Blood Donor Selection: Comparing Sero-Prevalence of Transfusion-Transmissible Infections Among Eligible and High-Risk Behavior Deferred Donors in Iran

Background: Eliminating high-risk individuals has a special role in ensuring blood safety. Due to epidemiological, demographic, and even cultural changes in each country, this process should be continuously evaluated and reviewed, if necessary. Objectives: This study aimed to evaluate the impact of the current donor selection procedure on blood safety in Iran. Methods: A total of 2,525 high-risk deferred donors who were referred between 2018 and 2019 were evaluated regarding hepatitis B surface antigen, hepatitis C virus antibody, and human immunodeficiency virus antigen and antibody. All repeatedly reactive samples were evaluated by confirmatory tests. Characteristics' parameters, donor status, and TTI marker rates of the participants and 1,315,871 eligible donors in the indicated period obtained from the national database on blood donors, were compared. Data were analyzed using SPSS version 24.0. Results: The prevalence of HBV, HCV, and HIV in 100,000 deferred donors was 1148, 515, and 119, respectively. This prevalence was 26, 28, and 33-times higher than the eligible donors, respectively. Unlike HBV, its prevalence among males was almost twice that of females among the deferred group. In the eligible group, females had a higher prevalence for HBV and HCV as compared to males. The HCV and HBV (6.7 and 4.3-fold) among deferred first-time donors had a significantly higher prevalence compared with the eligible first-time donors (P‐value < 001). Notably, the higher was the education degree, the lower was the prevalence of infection in both groups. Conclusions: Current deferral criteria and donor selection procedure in Iran are an opportunity to eliminate high-risk individuals from the blood donation.

Genetic Diversity of Human Immunodeficiency Virus Type 1 in Asymptomatic Blood Donors in Islamabad, Pakistan

Objective  The serological testing of human immunodeficiency virus (HIV) is mandatory under the blood safety legislation of Pakistan; hence, data exist on the prevalence of HIV in blood donors. However, little is known about the molecular epidemiology of HIV in the blood donor population. Therefore, the current study was designed to study the genetic diversity of HIV-1 infection in a population of apparently healthy treatment-naive blood donors in Islamabad, Pakistan.

Material and Methods  A total of 85,736 blood donors were tested for HIV by the chemiluminescence immunoassay. All positive donor samples were analyzed for the presence of various HIV genotypes (types and subtypes). Viral ribonucleic acid was extracted from blood samples of HIV positive donors and reverse transcribed into complementary deoxyribonucleic acid (cDNA). The cDNA of all positive donors was then analyzed for the presence of various HIV genotypes (types and subtypes) by employing subtype-specific primers in a nested polymerase chain reaction. The amplified products were run on ethidium bromide-stained 2% agarose gel and visualized using a ultraviolet transilluminator. A particular subtype was assigned to a sample if the subtype-specific reaction made a band 20% highly intense compared with the band made by the subtype-independent reaction.

Results  A total of 85,736 blood donors were screened for the presence of antibodies to HIV. Out of them, 114 were initially found reactive for HIV. The repeat testing resulted in 112 (0.13%) positive donors, 95% confidence interval 0.0014 (0.0011–0.0018). These 112 samples were analyzed for molecular typing of HIV-1. The predominant HIV-1 subtype was A ( n = 101) (90.1%) followed by subtype B ( n = 11) (9.9%).

Conclusion  These findings are key to understand the diversified HIV epidemic at the molecular level and should assist public health workers in implementing measures to lessen the further dissemination of these viruses in the country.

A Systematic Review of Interventions Used to Increase Blood Donor Compliance with Deferral Criteria

Background and Objectives

Pre-donation screening of potential blood donors is critical for ensuring the safety of the donor blood supply, and donor deferral as a result of risk factors is practised worldwide. This systematic review was conducted in the context of an expert review convened by the Australian Red Cross Lifeblood in 2013 to consider Lifeblood's injecting drug use (IDU)-related policies and aimed to identify studies assessing interventions to improve compliance with deferral criteria in blood donation settings.

Materials and Methods

MEDLINE/PubMed, OVID Medline, OVID Embase, LILACS, and the Cochrane Library (CENTRAL and DARE) databases were searched for studies conducted within blood donation settings that examined interventions to increase blood donor compliance with deferral criteria. Observational and experimental studies from all geographical areas were considered.

Results

Ten studies were identified that tested at least one intervention to improve blood donor compliance with deferral criteria, including computerized interviews or questionnaires, direct and indirect oral questioning, educational materials, and a combination of a tickbox questionnaire and a personal donor interview. High-quality evidence from a single study was provided for the effectiveness of a computerized interview in improving detection of HIV risk behaviour. Low-quality evidence for the effectiveness of computerized interviews was provided by 3 additional studies. Two studies reported a moderate effect of direct questioning in increasing donor deferral, but the quality of the evidence was low.

Conclusion

This review identified several interventions to improve donor compliance that have been tested in blood donation settings and provided evidence for the effectiveness of computerized interviews in improving detection of risk factors.

Prevention strategies of transfusion-transmitted parasitic infections (TTPIs): Strengths and challenges of current approaches, and evaluation of the strategies implemented in Iran

Background

Several strategies are being implemented in blood transfusion centers of the world to prevent the transfusion-transmitted parasitic infections (TTPIs). The objective of this study was to determine and describe the strategies to minimize the transmission risk of parasitic agents via blood transfusion in Iran.

Methods

This study was conducted in the Iranian blood transfusion organization (IBTO). The data were extracted from the latest version of the “medical interview” standard operating procedure (SOP).

Results

The donor selection is the first and only step to reduce the risk of TTPIs in endemic and non-endemic areas of Iran. In all blood transfusion centers of the IBTO, the blood donation volunteers with a previous history of malaria, Chagas disease, visceral leishmaniasis (VL), muco-cutaneous leishmaniasis and babesiosis, as well as those with clinical toxoplasmosis, cutaneous leishmaniasis (CL) and with a history of residence in, or travel to, malaria-endemic areas are permanently or temporarily deferred from the blood donation.

Conclusions

Since malaria, toxoplasmosis and VL are endemic in parts of Iran, as well as the increasing travels to endemic areas and immigrations from endemic to non-endemic areas of parasitic infections, the extensive use of blood and blood components and the asymptomatic occurrence of most parasitic infections in blood donors, the donor selection strategy is not sufficient to prevent the TTPIs. Therefore, the changing of donor selection process and the use of other common preventive strategies are recommended to reduce the risk of TTPIs, especially for high-risk groups of toxoplasmosis and VL.

Predictors of non-cystic fibrosis bronchiectasis in Indigenous adult residents of central Australia: results of a case-control study

The human T-cell leukaemia virus type 1 (HTLV-1) is associated with pulmonary inflammation. Indigenous Australians in central Australia have a very high prevalence of HTLV-1 infection and we hypothesised that this might contribute to high rates of bronchiectasis in this population. 80 Indigenous adults with confirmed bronchiectasis, each matched by age, sex and language to two controls without bronchiectasis, were recruited. Case notes and chest imaging were reviewed, HTLV-1 serology and the number of peripheral blood leukocytes (PBLs) infected with HTLV-1 (pro-viral load (PVL)) were determined, and radiological abnormality scores were calculated. Participants were followed for a mean±sd of 1.14±0.86 years and causes of death were determined. Median (interquartile range) HTLV-1 PVL for cases was 8-fold higher than controls (cases 213.8 (19.7-3776.3) copies per 105 PBLs versus controls 26.6 (0.9-361) copies per 105 PBLs; p=0.002). Radiological abnormality scores were higher for cases with HTLV-1 PVL ≥1000 copies per 105 PBLs and no cause of bronchiectasis other than HTLV-1 infection. Major predictors of bronchiectasis were prior severe lower respiratory tract infection (adjusted OR (aOR) 17.83, 95% CI 4.51-70.49; p<0.001) and an HTLV-1 PVL ≥1000 copies per 105 PBLs (aOR 12.41, 95% CI 3.84-40.15; p<0.001). Bronchiectasis (aOR 4.27, 95% CI 2.04-8.94; p<0.001) and HTLV-1 PVL ≥1000 copies per 105 PBLs (aOR 3.69, 95% CI 1.11-12.27; p=0.033) predicted death. High HTLV-1 PVLs are associated with bronchiectasis and with more extensive radiological abnormalities, which may result from HTLV-1-mediated airway inflammation.

Prevalence and associated risk factors of transfusion transmissible infections among blood donors at Regional Blood Transfusion Center Nakuru and Tenwek Mission Hospital, Kenya

Introduction

Unsafe transfusion practices can put millions of people at risk of Transfusion Transmissible Infections (TTIs). In Kenya the current blood transfusion scheme involves screening of blood for HIV, Hepatitis B virus (HBV), Hepatitis C virus (HCV) and syphilis. Malaria is also a blood-borne disease which is not currently screened for. In Kenya blood donor selection criteria were reviewed in 2009. Regular review of effectiveness of donor selection criteria can help reduce TTIs prevalence amongst donors and thus make the blood supply safer.

Methods

A cross sectional study was conducted between November 2011 to January 2012 among 594 blood donors in the Regional Blood Transfusion Center Nakuru and Tenwek Mission Hospital. Socio-demographic characteristics and associated risk factors were collected using a standard blood transfusion service questionnaire. Donors were obtained through systematic sampling. Each donor sample was screened, for HIV-1 and HIV-2, HBV, HCV, syphilis and malaria parasites.

Results

The overall prevalence of TTIs was 14.1%, which ranged from 0.7% for malaria to 5.6% for HBsAg. Blood donors who were married (P=0.0057), had non-formal or just primary education (P=0.0262), had multiple sexual partners (P=0.0144) and in informal occupation (P=0.0176) were at higher risk of HIV positivity. History of blood transfusion/blood products (P=0.0055), being married (P=0.0053) were high risk factors associated with positive syphilis. Being male (P=0.0479) was a high risk factor to HBV infection.

Conclusion

The prevalence of TTIs indicates a need to review the questionnaire and apply it strictly for donor selection. The 0.7% prevalence of malaria, poses a serious health risk to non-immune recipients of transfusion. Malaria should be included among mandatory TTI tests in Kenya.

Seroprevalence of human T-lymphotropic virus HTLV and its associated factors in donors of a blood bank of Medellín-Colombia, 2014-2018

BACKGROUND

Research on HTLV in Colombia is limited; despite being an endemic country there are few studies on the magnitude of this infection. The aim of this study was to determine the seroprevalence of HTLV I/II and its associated factors in donors to a blood bank of Medellín Colombia, 2014-2018.

METHODS

This is a cross-sectional study of 52,159 donors with a secondary information source. Seroprevalence of HTLV I/II was determined with its confidence interval and the population characteristics were described by frequency and summary measures. To explore the associated factors, Pearson's Chi square test, Mann-Whitney U test, crude odds ratios were used and they were adjusted by logistic regression in SPSS 25.0.

RESULTS

88% of the population lived in the metropolitan area, 68.5% belonged to the University. 76.2% were altruistic donors (unpaid donors who did not donate to a specific patient). 24.5% were repetitive (paid) donors. 75% of the donors were under 41 years old. The seroprevalence of HTLV I/II was 0.176% (95% CI = 0.139% -0.213%), being statistically lower in repetitive donors and men.

CONCLUSION

The seroprevalence of HTLV I/II infection in the studied blood bank is lower than that reported in other blood banks at the departmental and national levels. In Medellín, it was associated with the frequency of donation and gender, which is useful information for the hemovigilance programs of the city.

Seroprevalence of human T-lymphotropic virus (HTLV) in blood donors in sub-Saharan Africa: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Human T-cell lymphotropic viruses (HTLV) 1 and 2 are endemic in sub-Saharan Africa (SSA), transfusion-transmissible and causally linked to various severe diseases. However, even in SSA countries with moderate to high endemicity, routine blood donor screening for HTLV is rarely, if ever, performed. Information on seroprevalence is limited. The aim of this review is to establish the prevalence of HTLV-1 and HTLV-1/2 among blood donors in sub-Saharan Africa.

MATERIALS AND METHODS

We systematically reviewed databases including EMBASE, MEDLINE and the Cochrane database library from their inception to June 2018. Studies presenting data on HTLV prevalence among blood donors in sub-Saharan Africa were included. A random-effect meta-analysis was conducted on all eligible studies.

RESULTS

A total of 25 studies were included, representing 74 119 blood donors, of whom over 80% (61 002) were only tested for HTLV-1. The evidence base was high and moderate in quality. The pooled prevalence of the 17 studies that screened only for HTLV-1 and the nine studies that screened for HTLV-1/2 was 0·68 (95% CI: 0·29-1·60) and 1·11 (95% CI: 0·47-2·59) per 100 blood donors, respectively.

CONCLUSION

The prevalence of HTLV-1 infection among blood donors is relatively low. The current review is intended to inform debates and decisions about best practices to prevent transfusion-transmitted HTLV in sub-Saharan Africa. Further work is required to determine the risk of infections by transfusion and the cost-effectiveness of any new measures such as routine screening.

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.

What is changed in HBV molecular epidemiology in Italy?

Hepatitis B virus (HBV) infection represents the most common cause of chronic liver diseases worldwide. Consequently, to the introduction of the universal HBV vaccination program, the prevalence of hepatitis B surface antigen was markedly reduced and less than 1% of the population of Western Europe and North America is chronically infected. To date, despite great advances in therapeutics, HBV chronic infection is considered an incurable disease. Ten hepatitis B virus genotypes (A-J) and several subgenotypes have been identified so far, based on intergroup divergences of 8% and 4%, respectively, in the complete viral genome. HBV-D genotype has been found throughout the world, with highest prevalence in the Mediterranean area. In the present review, several articles concerning HBV epidemiology, and phylogeny in Italy have been analyzed, mainly focusing on the changes occurred in the last decade.

Which Infectious Blood Donors Could Be Identified by the Donor History Questionnaire? - Comparison of Blood Donors Infected with HIV or HCV with Notified Cases from General Population in Germany

Background

Potential risks for transfusion-transmissible infections are identified by donor history questionnaires (DHQs), and donors with higher risks are deferred from donation. We assessed to which extent the currently used DHQs support the identification of infections among blood donors.

Methods

Between 2006 and 2013, we analyzed data from notified HIV and HCV cases in the general population and positive blood donors in Germany. Logistic regressions were used to identify relevant infection risks. We estimated the possible effect of improved capture of risk factors for donor selection by calculation of population attributable fractions (PAF).

Results

Risky sexual contacts - MSM as well as heterosexual contacts - were the most prominent infection risks among HIV-infected donors. Whereas MSM contacts were significantly less reported by donors than by cases from the general population, 58% of donors disclosed heterosexual risks compared to 26% of notified cases. The complete identification of heterosexual risk contacts might prevent acceptance of 53% of HIV-infected donors. HCV-infected donors were more likely to report heterosexual exposure, imprisonment, and piercing/tattoo than notified HCV cases. Improved recording of piercing/tattoo could prevent acceptance of 16% of HCV-infected donors.

Conclusion

Donor selection should be improved with special attention to the identification of (hetero)sexual risk factors, invasive procedures (piercing/tattoo and imprisonment) applying well-designed DHQs, effective donor education, and confidential environment in all steps of the selection process.

Seroepidemiological Study of Hepatitis B, C and HIV among Blood Donors in Kerman

Background:

Infections transmitted through blood transfusions are the most important issue associated with blood donation. We aimed to provide an assessment of the prevalence of hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV) among blood donors in Kerman province of Iran.

Methods:

Between 2014-2016, 99,187 samples were examined in a retrospective study in five blood transfusion centers in Kerman province. Serologic screening for HBsAg, anti-HCV and anti-HIV1/2 was conducted for all samples and positive cases were confirmed.

Result:

The positives with the initial serological screening tests for HBsAg , anti-HCV and HIV 1/2 numbered 524, 409 and 285, respectively, and based on confirmation tests, final results were 196 , 72 and 1. The highest prevalences of HBV and HCV were reported as 0.36% in Jiroft city and 0.1% in Rafsanjan city. Co- infection with HBV and HCV was observed in the city of Sirjan.

Conclusion:

Blood-borne viral infections in people with low education levels were more common. The prevalence in Kerman province was low as compared to previous studies carried out in other regions of Iran. Application of standard operating procedures, with updated equipment, as well as planning for the use of molecular methods are necessary for the Iranian Blood Transfusion Organization, to monitor blood-transmitted infections.

Cancers in Australia in 2010 attributable to infectious agents

OBJECTIVES

To estimate the proportion and numbers of cancers in Australia in 2010 attributable to infectious agents.

METHODS

The population attributable fraction (PAF) and number of cancers caused by hepatitis B and C viruses (HBV, HCV), Helicobacter pylori and human immunodeficiency virus (HIV) were calculated using standard formulae incorporating prevalence of infection in the Australian population, the relative risks associated with that infection and cancer incidence. For cancers with very strong associations to the infectious agent (Epstein-Barr virus [EBV], human papillomavirus [HPV] and HIV/Kaposi's sarcoma herpes virus [KSHV]), calculations were based on viral prevalence in the tumour.

RESULTS

An estimated 3,421 cancers (2.9% of all cancers) in Australia in 2010 were attributable to infections. Infectious agents causing the largest numbers of cancers were HPV (n=1,706), H. pylori (n=793) and HBV/HCV (n=518). Cancer sites with the greatest number of cancers caused by infections were cervix (n=818), stomach (n=694) and liver (n=483). Cancers with highest proportions attributable to infectious agents were Kaposi's sarcoma (100%), cervix (100%), nasopharynx (87%), anus (84%) and vagina (70%).

CONCLUSIONS

Infectious agents cause more than 3,000 cancers annually in Australia.

IMPLICATIONS

Opportunities for cancer prevention through infection control are considerable, even in a 'first world' nation like Australia.

Health Technology Assessment of pathogen reduction technologies applied to plasma for clinical use

Although existing clinical evidence shows that the transfusion of blood components is becoming increasingly safe, the risk of transmission of known and unknown pathogens, new pathogens or re-emerging pathogens still persists. Pathogen reduction technologies may offer a new approach to increase blood safety. The study is the output of collaboration between the Italian National Blood Centre and the Post-Graduate School of Health Economics and Management, Catholic University of the Sacred Heart, Rome, Italy. A large, multidisciplinary team was created and divided into six groups, each of which addressed one or more HTA domains.Plasma treated with amotosalen + UV light, riboflavin + UV light, methylene blue or a solvent/detergent process was compared to fresh-frozen plasma with regards to current use, technical features, effectiveness, safety, economic and organisational impact, and ethical, social and legal implications. The available evidence is not sufficient to state which of the techniques compared is superior in terms of efficacy, safety and cost-effectiveness. Evidence on efficacy is only available for the solvent/detergent method, which proved to be non-inferior to untreated fresh-frozen plasma in the treatment of a wide range of congenital and acquired bleeding disorders. With regards to safety, the solvent/detergent technique apparently has the most favourable risk-benefit profile. Further research is needed to provide a comprehensive overview of the cost-effectiveness profile of the different pathogen-reduction techniques. The wide heterogeneity of results and the lack of comparative evidence are reasons why more comparative studies need to be performed.

Prevalence and Trends of Transfusion-Transmissible Viral Infections among Blood Donors in South of Iran: An Eleven-Year Retrospective Study

Background

Blood transfusion is considered a potential risk factor for transmission of life-threatening viral infections, including HIV, HCV and HBV infections. This study was performed to find out the prevalence and trends of these infections among blood donors in Southern Iran.

Methods

The blood donor data recorded in twelve regional blood transfusion centers from 2004 to 2014 were analyzed in an anonymous way with respect to the results of serological screening for HBV, HCV, and HIV infections. Overall, 293454 donors were screened for viral infections.

Results

Most of the donors were male, married, aged between 20–40 years, educated, and regular donors. The overall seroprevalence rates of HBV, HCV and HIV were 0.15%, 0.1% and 0.004%, respectively. The highest seroprevalence was found for HBV, followed by HCV and HIV. These infections were more prevalent in male, low educated and first time donors. The highest HCV seroprevalence was observed among donors aged 20 to 40 years, while HBV seroprevalence increased with age. The seroprevalence rates of HBV and HCV from 2004 to 2014 showed significant decreasing trends from 0.460% to 0.060% (P < 0.001) and 0.329% to 0.045% (P < 0.001), respectively. Whereas HIV infection had a slight but not significant decline from 0.0173% in 2004 to 0.0028% in 2014 (P = 0.087).

Conclusions

The decreasing trends of transfusion-transmissible viral infections in blood donations indicate that the attempts of IBTO were successful in improving the safety of the blood supply, since the prevalence rates of viral infections have been reduced to very low levels in blood donations over the years. However, still more effective techniques such as polymerase chain reaction (PCR) are needed to guarantee blood safety.

Selective Testing of At-Risk Blood Donors for Trypanosoma cruzi and Plasmodium spp. in Switzerland

BACKGROUND

Population migrations and overseas recreational travel to regions at risk for tropical diseases are increasing. A major challenge in non-endemic countries is to decrease the number of blood donor deferrals due those tropical disease pathogens, without compromising the high level of blood safety. The protozoans Trypanosoma cruzi and Plasmodium spp., the causative organisms of Chagas disease (CD) and malaria are becoming a major focus in the blood transfusion community.

METHODS

National guidelines of the Blood Transfusion Service of the Swiss Red Cross propose an algorithm for dealing with these pathogens, including a mandatory selective serological testing of donors at risk.

RESULTS

6,978 donors at risk for CD were tested. Three of them were confirmed anti-T. cruzi -positive, and in one case a transfusion-transmitted infection was highly possible. The specificity of the assay was 99.94%. For malaria 12,887 donors were at risk and 178 were confirmed positive. The specificity of the assays was 92.8%.

CONCLUSION

CD and malaria in non-endemic countries may represent a certain risk for blood transfusion. Switzerland chose a selective testing approach. The specificity of the assays is a crucial topic for this approach because it ensures a minimal loss of false-reactive donors and helps towards an easier counselling of implicated donors.

Donating blood for research: a potential method for enhancing customer satisfaction of permanently deferred blood donors

BACKGROUND

Each year, a large number of individuals in Australia are deferred from donating blood. A deferral may have a negative impact on donor satisfaction and subsequent word-of-mouth communication. The Australian Red Cross Blood Service (the Blood Service) is, therefore, investigating options for managing service interactions with deferred donors to maintain positive relationships. While public research institutes in Australia have established independent research donor registries, other countries provide programmes allowing deferred donors to donate blood for research via blood collection agencies. This study examined attitudes towards donating blood for research use in a sample of permanently deferred Australian donors.

MATERIALS AND METHODS

Donors permanently deferred because of a risk of variant Creutzfeldt-Jakob disease (n=449) completed a postal survey that examined attitudes towards research donation.

RESULTS

The majority of participants were interested in donating blood for research (96%), and joining a registry of research donors (93%). Participants preferred to donate for transfusion or clinical research, and were willing to travel large distances. Results indicated that positive attitudes towards the Blood Service would be extended if the opportunity to donate blood was provided. These findings indicate a desire for continued engagement with the Blood Service despite deferral.

DISCUSSION

Donating blood for research is a potential way of maintaining positive relationships with permanently deferred donors which also benefits the health research community. Through maintaining positive relationships with deferred donors, positive word-of-mouth activity can be stimulated. Further work is needed to determine the feasibility of implementing research donation through the Blood Service in Australia.

Human T-Lymphotropic Virus Type I (HTLV-1) Infection among Iranian Blood Donors: First Case-Control Study on the Risk Factors

Human T-cell lymphotropic virus type 1 (HTLV-1) infection is an endemic condition in Northeast Iran and, as such, identification of risk factors associated with the infection in this region seems to be a necessity. All the possible risk factors for HTLV-1 seropositivity among first-time blood donors were evaluated in Mashhad, Iran, during the period of 2011–2012. Blood donation volunteers were interviewed for demographic data, medical history, and behavioral characteristics and the frequencies of risk factors were compared between HTLV-1 positive (case) and HTLV-1 negative (control) donors. The data was analyzed using Chi square and t-tests. Logistic regression analysis was performed to identify independent risk factors for the infection. Assessments were carried out on 246 cases aged 17–60 and 776 controls aged 17–59, who were matched based on their ages, gender, and date and center of donation. Logistic analysis showed low income (OR = 1.53, p = 0.035), low educational level (OR = 1.64, p = 0.049), being born in the cities of either Mashhad (OR = 2.47, p = 0.001) or Neyshabour (OR = 4.30, p < 0001), and a history of blood transfusion (OR = 3.17, p = 0.007) or non-IV drug abuse (OR = 3.77, p < 0.0001) were significant predictors for infection with HTLV-1. Lack of variability or small sample size could be reasons of failure to detect some well-known risk factors for HTLV-1 infection, such as prolonged breastfeeding and sexual promiscuity. Pre-donation screening of possible risk factors for transfusion-transmissible infections should also be considered as an important issue, however, a revision of the screening criteria such as a history of transfusion for more than one year prior to donation is strongly recommended.

The risk of transfusion-transmitted viral infections at the Gabonese National Blood Transfusion Centre

BACKGROUND

Blood transfusions carry the risk of transmitting blood-borne infections. In contrast to the situation in the developed world, there is a limited number of studies examining this problem in sub-Saharan Africa. In this study we aimed to calculate the risks of acquiring human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) infection from units of blood issued by the Gabonese Blood Transfusion Centre between 2009 and 2011.

MATERIALS AND METHODS

All the donations were tested for infectious diseases and the seroconversion incidence rates of HIV, HBV and HCV were calculated. The residual risk of transfusion-associated transmission for each virus was calculated by multiplying the seroconversion rates by the window period expressed in fractions of a year.

RESULTS

The risks of becoming infected with HIV, HCV, and HBV in subjects receiving units of blood from the Gabonese Blood Transfusion Centre were 64.7, 207.94 and 534.53 per million donations, respectively.

CONCLUSIONS

This study, which is the first to quantify the true risks of transfusion-transmitted infections in Gabon, reveals and confirms the need to reinforce preventative and screening strategies to improve transfusion safety in sub-Saharan Africa.

Epidemiological Aspects and World Distribution of HTLV-1 Infection

The human T-cell leukemia virus type 1 (HTLV-1), identified as the first human oncogenic retrovirus 30 years ago, is not an ubiquitous virus. HTLV-1 is present throughout the world, with clusters of high endemicity located often nearby areas where the virus is nearly absent. The main HTLV-1 highly endemic regions are the Southwestern part of Japan, sub-Saharan Africa and South America, the Caribbean area, and foci in Middle East and Australo-Melanesia. The origin of this puzzling geographical or rather ethnic repartition is probably linked to a founder effect in some groups with the persistence of a high viral transmission rate. Despite different socio-economic and cultural environments, the HTLV-1 prevalence increases gradually with age, especially among women in all highly endemic areas. The three modes of HTLV-1 transmission are mother to child, sexual transmission, and transmission with contaminated blood products. Twenty years ago, de Thé and Bomford estimated the total number of HTLV-1 carriers to be 10-20 millions people. At that time, large regions had not been investigated, few population-based studies were available and the assays used for HTLV-1 serology were not enough specific. Despite the fact that there is still a lot of data lacking in large areas of the world and that most of the HTLV-1 studies concern only blood donors, pregnant women, or different selected patients or high-risk groups, we shall try based on the most recent data, to revisit the world distribution and the estimates of the number of HTLV-1 infected persons. Our best estimates range from 5-10 millions HTLV-1 infected individuals. However, these results were based on only approximately 1.5 billion of individuals originating from known HTLV-1 endemic areas with reliable available epidemiological data. Correct estimates in other highly populated regions, such as China, India, the Maghreb, and East Africa, is currently not possible, thus, the current number of HTLV-1 carriers is very probably much higher.

Transfusion safety in francophone African countries: an analysis of strategies for the medical selection of blood donors

BACKGROUND

The goal of selecting a healthy blood donor is to safeguard donors and reduce the risks of infections and immunologic complications for recipients.

STUDY DESIGN AND METHODS

To evaluate the blood donor selection process, a survey was conducted in 28 blood transfusion centers located in 15 francophone African countries. Data collected included availability of blood products, risk factors for infection identified among blood donor candidates, the processing of the information collected before blood collection, the review process for the medical history of blood donor candidates, and deferral criteria for donor candidates.

RESULTS

During the year 2009, participating transfusion centers identified 366,924 blood donor candidates. A mean of 13% (range, 0%-36%) of the donor candidates were excluded based solely on their medical status. The main risk factors for blood-borne infections were having multiple sex partners, sexual intercourse with occasional partners, and religious scarification. Most transfusion centers collected this information verbally instead of having a written questionnaire. The topics least addressed were the possible complications relating to the donation, religious scarifications, and history of sickle cell anemia and hemorrhage. Only three centers recorded the temperature of the blood donors. The deferral criteria least reported were sickle cell anemia, piercing, scarification, and tattoo.

CONCLUSIONS

The medical selection process was not performed systemically and thoroughly enough, given the regional epidemiologic risks. It is essential to identify the risk factors specific to francophone African countries and modify the current medical history questionnaires to develop a more effective and relevant selection process.

Surveillance of transfusion-transmissible infections comparison of systems in five developed countries

Most industrialized countries maintain surveillance programs for monitoring transmissible infection in blood donations, revising approaches to methodology and risk assessment as new threats emerge. A comparison of programs in the United States, Canada, France, the UK, and Australia indicates that they have similar function, although the structure of blood programs vary as does the extent and nature of formal ties with public health. The emergence of HIV in the late 1970s and early 1980s was key in recognizing that surveillance systems specific to blood transfusion were essential. Hence, most industrialized countries monitor transfusion-transmissible infections in donors and evaluate the impact of new testing and of predonation screening strategies. Emerging infections since HIV have had different transmission pathways and challenged blood programs to draw upon resources for a rapid and effective response, with recognition that the original focus on sexual/drug-related risk of HIV and hepatitis was inadequate. The focus of surveillance programs on new and emerging pathogens fulfills a key role in risk assessment and policy formulation. The precise nature of such activities varies by country because of the structure of the blood programs and surveillance systems, the strategic focus of the blood programs, and the epidemiology of disease in each country.

Preventive and therapeutic strategies for bovine leukemia virus: lessons for HTLV

Bovine leukemia virus (BLV) is a retrovirus closely related to the human T-lymphotropic virus type 1 (HTLV-1). BLV is a major animal health problem worldwide causing important economic losses. A series of attempts were developed to reduce prevalence, chiefly by eradication of infected cattle, segregation of BLV-free animals and vaccination. Although having been instrumental in regions such as the EU, these strategies were unsuccessful elsewhere mainly due to economic costs, management restrictions and lack of an efficient vaccine. This review, which summarizes the different attempts previously developed to decrease seroprevalence of BLV, may be informative for management of HTLV-1 infection. We also propose a new approach based on competitive infection with virus deletants aiming at reducing proviral loads.

Emerging viral threats to the Australian blood supply

OBJECTIVES

To assess the risk to the Australian blood supply posed by emerging or re-emerging viral infections.

METHOD

A review was undertaken of the English-speaking literature on the potential for emerging viral threats to human health in Australia, the future implications of virus ecology, climate change and population movement and the implications for blood transfusion.

RESULTS

Published data confirm that Australia's blood supply is among the safest in the world for currently screened viral pathogens as a result of rigorous surveillance, donor selection and state-of-the-art processing and laboratory testing. However, Australia has a number of other viral pathogens with the potential to threaten the safety of the blood supply such as the Ross River, Barmah Forrest, Kunjin, Japanese Encephalitis, Murray Valley Encephalitis and dengue viruses. Of these, dengue is currently of most concern to blood safety because; it can cause fatalities, there are regular seasonal outbreaks in Northern Australia and, in contrast to other viruses mentioned above an overseas case of transfusion transmission has already been documented. Notably, despite the lack of a suitable dengue screening test the ARCBS already implements supplementary measures to protect the blood supply during outbreaks.

CONCLUSION

Current interventions have proven extremely effective in minimising transfusion transmission in Australia of recognised viral pathogens. The threat posed by emerging viral pathogens to the safety of blood transfusion emphasises the need for global collaboration and consideration of further intervention strategies on a country by country basis including options such as nucleic acid testing and pathogen reduction technologies.