[HIV, HCV, HBV and syphilis surveillance among blood donors in Germany 2008-2010]

Epidemiology, Management, Quality of Testing and Cost of Syphilis in Germany: A Retrospective Model Analysis

Background

A multi-dimensional model can be a useful tool for estimating the general impact of disease on the different sectors of the healthcare system. We chose the sexually transmitted disease syphilis for our model due to the good quality of reported data in Germany.

Methods

The model included gender- and age-stratified incident cases of syphilis (in- and outpatients) provided by a German statutory health insurance company, as well as seroprevalence data on syphilis in first-time blood donors. Age standardized rates were calculated based on the standard German population. The test quality was assessed by extrapolating the number of false-positive and false-negative results based on data from Europe-wide external quality assessment (EQA) schemes. The model analysis was validated with the reported cases and diagnosis-related group (DRG)-statistics from 2010 to 2012. The annual direct and indirect economic burden was estimated based on the outcomes of our model.

Results

The standardized results were slightly higher than the results reported between 2010 and 2012. This could be due to an underassessment of cases in Germany or due to limitations of the dataset. The number of estimated inpatients was predicted with an accuracy of 89.8 %. Results from EQA schemes indicated an average sensitivity of 92.8 % and an average specificity of 99.9 % for the recommended sequential testing for syphilis. Based on our model, we estimated a total average minimal annual burden of €20,292,110 for syphilis on the German healthcare system between 2010 and 2012.

Conclusions

The linking of claims data, results from EQA schemes, and blood donor surveillance can be a useful tool for assessing the burden of disease on the healthcare system. It can help raise awareness in populations potentially at risk for infectious diseases, demonstrate the need to educate potential risk groups, and may help with predictive cost calculations and planning.

Retrospective Study of the Seroprevalence of HIV, HCV, and HBV in Blood Donors at a Blood Bank of Western Mexico

Obtaining blood which is safe for transfusions is one of the principal challenges in the health systems of developing countries. Supply of contaminated blood increases morbidity, mortality, and the costs of patient care. In Mexico, serological screening is mandatory, but only a few of the main blood banks routinely perform a nucleic acid test (NAT). Data from 80,391 blood donations processed between August 2018 and December 2019 at the Central Blood Bank of the Western National Medical Center of the Mexican Social Security Institute (IMSS) were analyzed. All donors were screened for serological markers and NAT was performed. Reactive donors were followed-up to confirm their results. The number of reactive donors and seroprevalence rates for HIV, HCV, and HBV were 152 (18.91/10,000), 385 (47.89/10,000), and 181 (22.51/10,000), respectively; however, these rates decreased when NAT-confirmed reactive results were considered. Male donors were found to have a higher seroprevalence than females, and younger donors higher than older donors. The present study shows that HIV, HCV, and HBV seroprevalence in blood donors in Western Mexico is low. We propose that Mexico should establish future strategies, including pathogen reduction technologies (PRTs), in order to improve blood safety and reduce transfusion-transmissible infections (TTIs).

Algorithms for the Testing of Tissue Donors for Human Immunodeficiency Virus, Hepatitis B Virus, and Hepatitis C Virus

Background

Although transmission of pathogenic viruses through human tissue grafts is rare, it is still one of the most serious dreaded risks of transplantation. Therefore, in addition to the detailed medical and social history, a comprehensive serologic and molecular screening of the tissue donors for relevant viral markers for human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) is necessary. In the case of reactive results in particular, clear decisions regarding follow-up testing and the criteria for tissue release must be made.

Methods

Based on the clinical relevance of the specific virus markers, the sensitivity of the serological and molecular biological methods used and the application of inactivation methods, algorithms for tissue release are suggested.

Results

Compliance with the preanalytical requirements and assessment of a possible hemodilution are mandatory requirements before testing the blood samples. While HIV testing follows defined algorithms, the procedures for HBV and HCV diagnostics are under discussion. Screening and decisions for HBV are often not as simple, e.g., due to cases of occult HBV infection, false-positive anti-HBc results, or early window period positive HBV NAT results. In the case of HCV diagnostics, modern therapies with direct-acting antivirals, which are often associated with successful treatment of the infection, should be included in the decision.

Conclusion

In HBV and HCV testing, a high-sensitivity virus genome test should play a central role in diagnostics, especially in the case of equivocal serology, and it should be the basis for the decision to release the tissue. The proposed test algorithms and decisions are also based on current European recommendations and standards for safety and quality assurance in tissue and cell banking.

[How to assess the elimination of viral hepatitis B, C, and D in Germany? Outcomes of an interdisciplinary workshop]

Hintergrund

Die Weltgesundheitsorganisation (WHO) hat 2016 eine Strategie zur Eliminierung von Hepatitis-B-, -C- und -D-Virusinfektionen verfasst und Indikatoren zum Monitoring des Fortschritts definiert. Das Robert Koch-Institut hat 2019 ein interdisziplinäres Arbeitstreffen zur Verbesserung der Datenlage veranstaltet.

Ziele

Ziele waren die Vernetzung der Akteure, die Erstellung einer Übersicht zu den in Deutschland vorhandenen Datenquellen zu Hepatitis B, C und D und die Diskussion methodischer Aspekte.

Material und Methoden

Die für Deutschland relevanten WHO-Indikatoren wurden extrahiert und es wurde bestimmt, wie diese anhand vorliegender Daten konstruiert werden können. Bei dem Arbeitstreffen mit AkteurInnen aus dem öffentlichen Gesundheitsdienst, aus Kliniken, Laboren, von Krankenkassen, Forschungsinstituten, Datenhaltern und Registern wurden in Arbeitsgruppen Erhebungsmethoden diskutiert, welche dazu dienen können, fehlende Daten zu ermitteln. Die Datenquellen und Daten wurden hinsichtlich Qualität, Vollständigkeit sowie praktischer Umsetzbarkeit evaluiert und priorisiert.

Ergebnisse

Für die Allgemeinbevölkerung können die Indikatoren zu Prävention, Testung, Diagnose, Behandlung, Heilung, Folgeschäden und Mortalität aus Diagnose‑, Versorgungs- und Registerdaten, Daten aus Laboren und klinischen Zentren sowie einzelnen Studien konstruiert werden. Datenquellen für vulnerable Gruppen beschränken sich auf einzelne Studien zu Drogengebrauchenden, Männern, die Sex mit Männern haben, und HIV-Ko-Infizierten. Daten für MigrantInnen, Inhaftierte und SexarbeiterInnen sind kaum verfügbar; ebenso fehlen aktuelle Daten zur Krankheitslast chronischer Hepatitisinfektionen in der Allgemeinbevölkerung.

Diskussion

Für alle ausgewählten Indikatoren konnten Datenquellen, ihre Besonderheiten und Limitationen identifiziert werden. Im nächsten Schritt gilt es, die entwickelten Ideen in konkrete Projekte mit einzelnen Datenhaltern umzusetzen.

Zusatzmaterial online

Zusätzliche Informationen sind in der Online-Version dieses Artikels (10.1007/s00103-020-03260-2) enthalten.

Prevalence of Hepatitis B, C, and D in Germany: Results From a Scoping Review

Background: One of the five strategic directions in the World Health Organization global health sector strategy on viral hepatitis 2016-2021 is to generate strong strategic information for focused action to understand the viral hepatitis epidemic and focus the response. Knowledge of national prevalence is a cornerstone of strategic information. Germany is considered to be a low prevalence country for viral hepatitis B, C, and D, however the prevalence is likely to be higher among at-risk groups. Methods: The aim of this work was to give a detailed overview of the prevalence of viral hepatitis B (HBsAg, anti-HBc), C (anti-HCV, HCV RNA), and D (anti-HDV, HDV RNA) in different population groups in Germany. Therefore, we analyzed the results of a comprehensive literature search on various aspects of the epidemiological situation of hepatitis B, C, and D in Germany. Eligible publications including information on hepatitis B, C, and D prevalence were extracted from the overall spreadsheet table and summarized and analyzed based on virus and different population groups. A quality appraisal was performed using a checklist developed by Hoy et al. to assess risk of bias in prevalence studies. Results: Overall, 51 publications were identified through the literature search. The overall prevalence of HBsAg in the general (and proxy) population ranged from 0.3 to 1.6%. Among at-risk groups, including clinical populations and health care workers, the HBsAg prevalence ranged from 0.2% (among rheumatic patients) to 4.5% among HIV positive patients. The overall prevalence of anti-HCV in the general (and proxy) population ranged from 0.2 to 1.9%. Among at-risk groups, including clinical populations and health care workers, the anti-HCV prevalence ranged from 0.04% (among health care workers) to 68.0% among people who inject drugs. Conclusions: The hepatitis B and C prevalence in the general population in Germany is low. Prevalence is high to very high among at-risk populations, however for some groups evidence was incomplete or missing completely. To reach the elimination goals in Germany and implement a targeted response, more research among at-risk groups is needed.

The epidemiology of Hepatitis B, C and D in Germany: A scoping review

BACKGROUND

Germany is considered to be a low prevalence country for viral Hepatitis B, C and D (HBV, HCV, HDV). However, the burden of disease can be high among subpopulations. To meet the world Health Organization (WHO) viral hepatitis (VH) elimination goals, a national strategy was developed by the German government in 2016. We performed a scoping review to understand the baseline epidemiological situation in Germany regarding burden of disease, sequelae and care of HBV, HCV and HDV as a reference to monitor the progress of the national VH elimination and to identify further knowledge gaps and research needs.

METHODS

The protocol of the systematic review was prepared following the PRISMA statement guidelines for scoping reviews. Relevant search terms were used to identify eligible studies according to the research questions. We searched six online databases for original work published between January 2005 and March 2017. Based on the identified references, a matrix was developed presenting the eligible literature by targeted population group and outcome category.

RESULTS

104 publications were eligible for extraction covering 299 outcome results. The population groups targeted in the identified studies included the general population and proxy populations, a range of clinical populations, people who inject drugs, men who have sex with men, healthcare workers, people in prisons and different migrant/mobile populations. Other vulnerable populations (e.g. sex workers) were not targeted. Overall, good evidence was found for HBV and HCV prevalence and HBV vaccination coverage in the GP and proxy populations. Evidence for these outcomes was weaker in populations at risk for VH. For HBV and HCV incidence and mortality, we identified large evidence gaps in all population groups. Outcomes on VH sequelae and care were mainly covered by studies in clinical populations of people living with viral hepatitis. For HDV the overall evidence available was scarce.

CONCLUSIONS

We created a comprehensive evidence-based overview on the current epidemiological situation of viral hepatitis in Germany. We identified knowledge gaps for further research and established a baseline for future monitoring of viral hepatitis elimination goals in Germany.

Seroprevalence and risk factors on Syphilis among blood donors in Chengdu, China,from 2005 to 2017

Background

High-risk population of blood donation increases the prevalence of transmit blood-borne diseases and harm the blood safety. Syphilis accounts for approximately 10% of commonly sexually transmitted diseases. The risk factors for blood donors infected with syphilis are also risk factors for other blood borne diseases. The objective of the study is to investigate the seroprevalence and risk factors on syphilis among blood donors, and analyze the donation status of high-risk population.

Methods

A retrospective study was conducted in Chengdu Blood Center during 2005 and 2017. Serological test results of volunteer blood donors were collected. Conditional logistic regression models were performed to investigate syphilis-related risk factors and population attributable risk (PAR) was performed to predict the tendencies of high-risk populations’ on risky behaviors.

Results

The serological epidemic for syphilis among blood donors in Chengdu showed an upward trend from 2005 to 2017.TP positive blood donors were more likely to have multiple sexual partners and commercial sex (50.6% vs.22.6, 11.1% vs.4.6%). Multiple condition logistic regression model denoted the following risk factors for increasing rates of syphilis infections: multiple sexual partners (OR = 7.1, 95% CI:1.72–6.58), razor reuse (OR = 1.7;, 95% CI:1.01–2.01); ear piercing (OR = 2.7, 95% CI:1.48–3.37); tattoo (OR = 3.3, 95% CI:1.17–6.78); condom occasionally (OR = 2.8, 95% CI:0.68–1.66). The PAR for each of the risk factors were 0.225, 0.144, 0.147, 0.018, 0.129, 0.018, respectively.

Conclusion

Health consultation and screening of high-risk groups before blood donation need to be further improved. Blood donor recruitment should emphasize on excluding the high-risk donors and recruiting more low-risk blood donors. In addition, this study also shows that sharing cosmetic surgical instrument has been proven to transmit blood-borne diseases. Therefore, the syphilis in blood circulation should not be ignored.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4128-7) contains supplementary material, which is available to authorized users.

Effectiveness of blood donor screening by HIV, HCV, HBV-NAT assays, as well as HBsAg and anti-HBc immunoassays in Germany (2008-2015)

Background and Objectives

In Germany, in addition to standard blood donor screening, further mandatory tests were introduced for HCV‐RNA, HIV‐1‐RNA and for anti‐HBc. Screening for HBV‐DNA is optional. This study investigates the benefits of these additional tests for the detection of HIV, HCV, and HBV infections among German blood donors.

Materials and Methods

From 2008 to 2015 we collected data on blood donations exclusively testing NAT positive (NAT yield) or reactive in only one of the screening assays. Assuming a Poisson distribution, we calculated NAT yield/reactive only rates on a per donation basis (number of yield/reactive only cases divided by the number of donations tested in the period under review) with 95% confidence intervals.

Results

Responding establishments covered 95% of the donations. We identified 20 HIV‐1‐NAT, 61 HCV‐NAT and 29 HBV‐NAT yield cases among approximately 46 million blood donations tested corresponding to 0·43 HIV‐1 NAT, 1·32 HCV‐NAT, and 0·64 HBV‐NAT yield cases per million blood donations tested. For one HBsAg reactive only case and 23 anti‐HBc reactive only cases in repeat donors, infection was confirmed by ID‐NAT which translates into 0·02 and 0·55 cases per million donations tested. During the 8‐year‐observation period, one HIV‐1, no HCV and four HBV transmissions associated with donations in the viremic pre‐seroconversion window period were reported.

Conclusion

Annually, NAT screening alone detected 2·5 HIV‐1, 7·6 HCV, and 3·6 HBV infectious donations; anti‐HBc screening alone identified 2·9 infectious donations of repeat donors with occult HBV infection. Overall, the survey results support that the currently practiced donor HIV/HCV/HBV screening strategy in Germany does ensure a high standard of blood safety.

Anti-HBc screening - is it worth the effort? Results of a 10-year surveillance programme covering more than 30 million donations in Germany

BACKGROUND AND OBJECTIVES

Antibodies to hepatitis B core antigen (anti-HBc) testing were added to hepatitis surface antigen (HBsAg) screening in Germany in 2006 to prevent hepatitis B virus (HBV) transmissions by chronically infected donors. We report the results of a national surveillance of anti-HBc-reactive and HBsAg-negative donations and assess the resulting gain in blood safety and the donor loss.

MATERIALS AND METHODS

Donations were tested for anti-HBc, and if reactive, by sensitive individual donation nucleic acid testing (ID-NAT) and for antibodies to HBsAg (anti-HBs). Data from the national anti-HBc surveillance from 2006 to 2015 determined the proportion of anti-HBc-reactive donations stratified for donor type, sex, anti-HBs concentration and NAT-positivity. Donor loss due to anti-HBc-reactive results was quantified.

RESULTS

Of 31 562 556 donations screened, 70 671 were anti-HBc reactive but HBsAg negative (0.22%). The proportion of repeat donors with these test results decreased significantly from 0.25% in 2007 to 0.08% in 2015. In the entire study period, 82 HBV-NAT-positive donations were identified. Of these, 47 donations were only identified by ID-NAT. A total of 54 203 anti-HBc-reactive units were discarded either due to possible infectiousness (NAT positive or anti-HBs concentration <100 IU/l) or because no further testing was performed.

CONCLUSION

Anti-HBc screening has improved blood safety in Germany. HBV-NAT-positive donations were identified after ID-NAT was triggered by the initial reactive anti-HBc result. The observed loss of donations was sustainable for maintaining an adequate blood supply in Germany.

Selecting the Right Donors - Still a Challenge: Development of a Uniform Donor Questionnaire in Germany

The selection of blood donors includes the assessment of the individual's health and medical history by using a donor questionnaire (DQ) in order to identify persons whose donation could present a health risk to recipients or to themselves. This way, DQs provide one layer of blood safety and contribute to the high safety profile of blood components currently available in Germany. This review reports the development of a new uniform questionnaire in Germany and its first evaluation using a field test approach. This development is set in context with the international experiences regarding donor selection and prospective challenges.

Good Feasibility of the New German Blood Donor Questionnaire

BACKGROUND

We assessed the effect of the uniform donor questionnaire (UDQ) on deferral rates in first-time and repeat donors. We focused on the introduced question about unprotected sexual contact with a new partner. Another goal was a stratified comparison of the deferral rates of the donor questionnaire (DQ) and UDQ.

METHODS

Data on donors and deferrals using the DQ and UDQ were collected at four blood establishments. The comparison included a 2-year period by questionnaire version. For the comparison of the questionnaires, an adjusted multinomial logistic regression was performed.

RESULTS

The analysis included 260,848 donations. First-time (FTD) and repeat donations (RD) showed higher deferral rates with the UDQ (FTD +5.4%, RD +1.4%). Deferral due to a new partner was 3.0% in first-time and 0.4% in repeat donors. The majority of these occurred in the youngest age groups. The most frequent deferral criterion was 'disease' (5.1%).

CONCLUSION

The regression revealed stronger predictors for deferral than the questionnaire version. Especially younger age carried a higher and independent risk for deferral. The additional deferrals of mainly young first-time donors due to a new sexual partner may identify those donors with potential heterosexual risk behavior who would otherwise not be identified.

Implications of a switch to a 100% apheresis platelet supply for patients and for blood donors: a risk benefit analysis

BACKGROUND

A 100% apheresis platelet supply is considered to increase transfusion safety by lowering donor exposures for transfusion recipients. We performed a risk benefit analysis to contrast the reduction of donor exposures and the risk of contaminated blood products in the nation-wide inventory with the donor risks associated with a switch to a 100% apheresis platelet supply in Germany.

METHODS

Donor exposures and the number of contaminated blood products resulting from HIV-like, HBV-like, HCV-like pathogens and two theoretical agents with infection rates of 10 and 1000 in 100 000, respectively, were calculated for a 100% apheresis platelet supply in Germany based on the 2006-2012 hemovigilance reports. These numbers were compared with the current mixed platelet supply of pooled and apheresis platelets. Moreover, additional donation time and apheresis donor complications resulting from a 100% apheresis platelet supply were estimated.

RESULTS

Per million total blood products (red cells, platelets, fresh frozen plasma), a 100% apheresis platelet supply would reduce donor exposures by 87 100 and the number of contaminated blood products ranging from 0·8 to 871·1. On the other hand, this requires additional 29 478 apheresis donations, 3·4 years additional donor time, and would be associated with 58 additional donor complications, respectively.

CONCLUSIONS

A 100% apheresis platelet supply would reduce donor exposures and the number of contaminated blood products in the inventory, but would increase apheresis complications in donors. Potential risks for patients must be carefully weighed against the risks for donors, dependent on the specific pathogen scenario.

Implementation of an HIV-1 Triple-Target NAT Assay in the Routine Screening at Three German Red Cross Blood Centres

BACKGROUND

Blood product safety was significantly improved by the introduction of NAT testing in the late 1990s, resulting in a strong decrease of transfusion-transmitted infections (TTIs). Due to the occurrence of HIV-1 NAT test failures as a consequence of mismatch mutations in the amplicon regions of mono-target NAT assays, the Paul Ehrlich Institute mandated the implementation of multi-target NAT assays for HIV-1 in 2014. Commercial suppliers mostly developed dual-target NAT assays, with only one implementing a triple-target NAT assay.

METHODS

The HIV-1 triple-target NAT assay v3 (GFE Blut) was tested on mutated specimens and synthetic DNA bearing mutations that resulted in sample underquantification or false-negative test results. In addition, data from 2 years routine testing at three German Red Cross Blood centres were analysed.

RESULTS

The HIV-1 triple-target PCR could compensate for all mutations tested and could compensate the loss of one amplicon without a significant loss of sensitivity. Data from 2 years routine testing showed a solid performance.

CONCLUSION

The HIV-1 triple-target v3 assay (GFE Blut) can compensate mutations in target sequences better than a dual-target assay and is applicable to high-throughput screening, thus increasing blood product safety.

Modelling the prevalence of hepatitis C virus amongst blood donors in Libya: An investigation of providing a preventive strategy

AIM: To determine hepatitis C virus (HCV) seroprevalence among the Libyan population using blood donors and applying the autoregressive integrated moving average (ARIMA) model to predict future trends and formulate plans to minimize the burden of HCV infection.

METHODS: HCV positive cases were collected from 1008214 healthy blood donors over a 6-year period from 2008 to 2013. Data were used to construct the ARIMA model to forecast HCV seroprevalence among blood donors. The validity of the model was assessed using the mean absolute percentage error between the observed and fitted seroprevalence. The fitted ARIMA model was used to forecast the incidence of HCV beyond the observed period for the year 2014 and further to 2055.

RESULTS: The overall prevalence of HCV among blood donors was 1.8%, varying over the study period from 1.7% to 2.5%, though no significant variation was found within each calendar year. The ARIMA model showed a non-significant auto-correlation of the residuals, and the prevalence was steady within the last 3 years as expressed by the goodness-of-fit test. The forecast incidence showed an increase in HCV seropositivity in 2014, ranging from 500 to 700 per 10000 population, with an overall prevalence of 2.3%-2.7%. This may be extended to 2055 with minimal periodical variation within each 6-year period.

CONCLUSION: The applied model was found to be valuable in evaluating the seroprevalence of HCV among blood donors, and highlighted the growing burden of such infection on the Libyan health care system. The model may help in formulating national policies to prevent increases in HCV infection and plan future strategies that target the consequences of the infection.

Current concepts in the prevention of pathogen transmission via blood/plasma-derived products for bleeding disorders

The pathogen safety of blood/plasma-derived products has historically been a subject of significant concern to the medical community. Measures such as donor selection and blood screening have contributed to increase the safety of these products, but pathogen transmission does still occur. Reasons for this include lack of sensitivity/specificity of current screening methods, lack of reliable screening tests for some pathogens (e.g. prions) and the fact that many potentially harmful infectious agents are not routinely screened for. Methods for the purification/inactivation of blood/plasma-derived products have been developed in order to further reduce the residual risk, but low concentrations of pathogens do not necessarily imply a low level of risk for the patient and so the overall challenge of minimising risk remains. This review aims to discuss the variable level of pathogenic risk and describes the current screening methods used to prevent/detect the presence of pathogens in blood/plasma-derived products.

Two decades of risk factors and transfusion-transmissible infections in Dutch blood donors

BACKGROUND

Risk behavior-based donor selection procedures are widely used to mitigate the risk of transfusion-transmissible infections (TTIs), but their effectiveness is disputed in countries with low residual risks of TTIs.

STUDY DESIGN AND METHODS

In 1995 to 2014, Dutch blood donors infected with hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), human T-lymphotropic virus (HTLV), or syphilis were interviewed by trained medical counselors to identify risk factors associated with TTIs. Trends in the prevalence and incidence of TTIs were analyzed using binomial regression models.

RESULTS

A total of 972 new donors and 381 repeat donors had TTIs. New donors had higher rates of TTIs compared to repeat donors. Although the HBV and HCV prevalence gradually decreased over time, the incidence of all five TTIs remained stable during the past two decades. In new donors the TTIs had the following risk profiles: "blood-blood contact" for HCV, "unprotected sex" for HIV and syphilis, and "country of birth" for HBV and HTLV. In infected repeat donors, sexual risk factors predominated for all TTIs. At posttest counseling, 28% of infected repeat donors admitted to risk factors leading to permanent donor exclusion if revealed during the donor selection procedure (predominantly male-to-male sex and recent diagnosis of syphilis).

CONCLUSION

The prevalence and incidence of TTIs among Dutch blood donors are six- to 60-fold lower than in the general Dutch population, illustrating the effectiveness of donor selection procedures. However, at least a quarter of infected donors appeared noncompliant to the donor health questionnaire (DHQ), suggesting that DHQs, or the way donor questioning is implemented, can be improved.

Estimating the residual risk for HIV, HCV and HBV in different types of platelet concentrates in Germany

BACKGROUND AND OBJECTIVES

We estimated and compared the residual risks due to window-period donations for pooled and apheresis platelets in Germany using a modification of a previously described statistical model. This model directly utilizes the reported interdonation intervals before a positive donation and reflects in this aspect the look-back procedures used in haemovigilance.

MATERIALS AND METHODS

Data from the German National Blood Donor Surveillance System for the years 2006-2012, including reports about donations from repeat donors with confirmed positive test results for HIV, HCV and HBV, were used to estimate the risk of undetected infectious units for both pooled and apheresis platelets.

RESULTS

Demographics of whole-blood and apheresis donors differed in age, gender, catchment area and interdonation interval. These differences impact on the prevalence and incidence of transfusion relevant infections and consequently the residual risk. The estimates for the residual risks for pooled and apheresis platelets were comparable. For HIV, there was no significant difference, for HCV apheresis platelets had a lower residual risk, whereas pooled platelets had a lower risk for undetected HBV infections.

CONCLUSION

These findings do not support calls for a shift to an apheresis platelets-only policy in Germany.

Syphilis seroprevalence estimates of Santa Catarina blood donors in 2010

INTRODUCTION

Knowledge of blood donor characteristics is essential to better guide clinical and serological screening for hemotherapy. The objective of this study was to determine the syphilis seroprevalence and the associated factors of blood donors in the State of Santa Catarina, Brazil.

METHODS

This population-based study from the State of Santa Catarina used information obtained from blood donation records. We analyzed 83,396 blood donor records generated from donors who were considered eligible to donate between January and August 2010. The aim of the study was to estimate the syphilis seroprevalence and its relationship with educational level, age, gender, geographical region and having donated blood in the past 12 months. We used descriptive analyses and a Poisson regression to calculate the prevalence ratios for the variables of interest.

RESULTS

We found a 0.14% overall seroprevalence and significant differences among the following: first-time blood donors (0.19%) versus repeat donors (0.03% to 0.08%); low educational levels (0.30%) versus medium and high educational levels (0.08% to 0.19%); and donors who did not report their residence (0.88%) or age (6.94%) versus those who did. Increased syphilis seroprevalence was also significantly associated with increased age.

CONCLUSION

High syphilis seroprevalence was associated with lower educational level, age, first-time donation and the failure to provide age or residence information.

Sexual risk behaviour and donor deferral in Europe

One of the most controversial policies in blood transfusion worldwide is the permanent deferral from donating blood of men with sexual contacts to other men (MSM). This policy was implemented for safety reasons as sex between men is known to be a high risk factor for acquiring severe infectious diseases transmissible by blood transfusion. Sexual contacts among heterosexual persons may hold similar risks but a clear-cut discrimination between different individual risks is impossible. Nevertheless, the current blood donor deferral periods defined by European Union (EU) legislation depend on a distinction of different grades of risk with respect to sexual behaviour. Under the aegis of the Steering Committee on Blood Transfusion (CD-P-TS) of the Council of Europe (CoE), an international working group evaluated epidemiological and behavioural data, modelling studies on residual risk and spread of infections, and studies on adherence to donor selection criteria. The aim was to distinguish sexual behaviour of different risk categories. It was concluded, that existing data confirm that MSM and commercial sex workers (CSW) are groups at high risk. Any further grading lacks a scientific data base. Modelling studies indicate that adherence to deferral policies is of major relevance suggesting that good donor adherence may outweigh the small negative effects on blood safety postulated for changing from permanent to temporary deferral periods for high risk sexual behaviours. The fact that a considerable percentage of donors are MSM - despite the permanent deferral policy - demonstrates the need to increase donor understanding and adherence.

Blood donation by elderly repeat blood donors

BACKGROUND

Upper age limits for blood donors are intended to protect elderly blood donors from donor reactions. However, due to a lack of data about adverse reactions in elderly blood donors, upper age limits are arbitrary and vary considerably between different countries.

METHODS

Here we present data from 171,231 voluntary repeat whole blood donors beyond the age of 68 years.

RESULTS

Blood donations from repeat blood donors beyond the age of 68 years increased from 2,114 in 2005 to 38,432 in 2012 (from 0,2% to 4.2% of all whole blood donations). Adverse donor reactions in repeat donors decreased with age and were lower than in the whole group (0.26%), even in donors older than 71 years (0.16%). However, from the age of 68 years, the time to complete recovery after donor reactions increased. Donor deferrals were highest in young blood donors (21.4%), but increased again in elderly blood donors beyond 71 years (12.6%).

CONCLUSION

Blood donation by regular repeat blood donors older than 71 years may be safely continued. However, due to a lack of data for donors older than 75 years, blood donation in these donors should be handled with great caution.

Defining acceptable epidemiology ranges in donor populations based on the contamination risk of finished plasma-derived products

BACKGROUND

For a given plasma-derived product, the risk of final product contamination by hepatitis B virus, hepatitis C virus and human immunodeficiency virus depends upon the epidemiology in the donor population, the virus load in a donation, the product yield and the effective virus reduction capacity in manufacturing.

STUDY DESIGN AND METHODS

A Monte Carlo simulation model was developed to estimate the risk of virus contamination of a final product resulting from virus contamination of plasma pools for fractionation. The model was run for both source and recovered plasma at various incidence rates for the three viruses to determine virus loads in minipools and fractionation pools resulting from donations with virus levels below test sensitivities. Together with the virus reduction capacity and yield of a theoretical worst case plasma-derived product, the contamination risk in a final vial was calculated.

RESULTS

Acceptable upper-bound centre-level incidence rates in the donor population (per donor centre) result in final products with very high margins of virus safety; the largest determinant of these 'Process Limits' is the virus reduction capacity of the manufacturing process. Short donation intervals and long inventory hold periods for source plasma compensates the lower incidence rates typically observed in recovered plasma donors.

CONCLUSIONS

The model calculates process limits for epidemiological data at collection centres based on an appropriate margin of virus safety for final products. The model also takes into consideration the impact of different donor/donation management systems for source and recovered plasma on the number of low viraemic donations entering the plasma pool for fractionation.

Risk Minimization Measures for Blood Screening HIV-1 Nucleic Acid Amplification Technique Assays in Germany

BACKGROUND

Several publications describe HIV-1 RNA false-negative results or viral load underquantitation associated with Communauté Européenne(CE)-marked qualitative or quantitative nucleic acid amplification technique (NAT) assays. 6 cases occurred during blood screening in Germany, with 2 of them causing HIV-1 transmissions to recipients of blood components. The implicated NAT assays were mono-target assays amplifying in different viral genome regions (gag or long terminal repeat).

METHODS

Specimens characterized by HIV-1 NAT underquantitation or false-negative NAT results were comparatively investigated in CE-marked HIV-1 NAT systems of different design to identify potential reasons. The target regions of the viral nucleic acids were sequenced and these sequences compared to primers and probes of the assays. Potential risk minimization measures were considered for quantitative and blood-screening HIV-1 NAT systems.

RESULTS

Nucleotide sequencing of the viral target region in cases of HIV-1 RNA underquantitation or false-negative test results revealed new HIV-1 variants that were mismatched with primers and probes used in some mono-target assays. So far, dualtarget NAT assays have not been associated with mismatch-based false-negative test results. From 2015, the Paul Ehrlich Institute will request HIV-1 NAT assays of dual-target design or an analogous solution for further reducing the risk in blood screening.

CONCLUSION

HIV differs from other blood-borne viruses with regard to its fast evolution of new viral variants. The evolution of new sequences is hardly predictable; therefore, NAT assays with only 1 target region appear to be more vulnerable to sequence variations than dual-target assays. The associated risk may be higher for HIV-1 NAT assays used for blood screening compared to quantitative assays used for monitoring HIV-1-infected patients. In HIV-1 screening NAT assays of dual-target design may adequately address the risk imposed by new HIV-1 variants.

How safe is safe: new human immunodeficiency virus Type 1 variants missed by nucleic acid testing

BACKGROUND

Nucleic acid amplification techniques (NAT) in routine blood donor screening considerably reduce the diagnostic window phase period. Nevertheless, several reports of false-negative NAT results were published. Here, four cases of human immunodeficiency virus Type 1 (HIV-1) RNA-positive blood donations that escaped detection by NAT screening are described.

STUDY DESIGN AND METHODS

A total of 2.7 million blood donations were screened for viral infections between January 2010 and October 2012 in our German Red Cross blood donation service. Four plasma specimens with false-negative NAT results were comparatively investigated with 12 CE-marked NAT assays. In two cases of putative HIV-1 variants the target region of the NAT assay was sequenced allowing comparison with the respective primers and probes.

RESULTS

Most of the NAT assays used in routine blood donor screening with the 5'-long terminal repeat (LTR) as target region demonstrated deficiencies in detecting the viral variants and the low-viral-carrier donations. Sequence analysis revealed in one case a deletion of 56 nucleotides within the 5'-LTR preventing the binding of the probe accompanied by a neighbored insertion of another 52 nucleotides and several primer mismatches in another case. No false-negative results were obtained for these cases using dual-target assays. The viral load of the remaining two false-negative results was below the NAT's limit of detection.

CONCLUSION

HIV-1 is characterized by a high mutation rate and rapid generation of new viral variants. By the use of one target region for HIV-1 NAT assays there is a certain risk of false-negative results. Employing HIV-1 multi- and dual-target assays in routine blood donor screening seems to be a reasonable possibility to minimize this problem.