Safe supplies: few infections in UK blood and tissue donors

Determining the strength of evidence for an association between sexual indicators and risk of acquiring HIV and sexulaly transmitted infections: Providing evidence for blood donation policy change

In 2019 the For The Assessment Of Individualised Risk (FAIR) project began a review of UK blood donor selection policy to determine if a more individualised approach to donor selection could be safely implemented. An evidence base was required to inform selection policy to move from a population to a more individual based policy, specifically what sexual behaviours/indicators should be considered as screening questions to maintain the safety of the blood supply. Eight sexual behaviours/indicators were reviewed: history of bacterial sexually transmitted infections (STIs), chemsex, number of recent partners, condom use, type of sex, sexual health service (SHS) attendance, new sexual partner and exclusivity. We conducted searches in multiple databases to identify literature looking at the association between these behaviours/indicators and HIV/STI acquisition risk. A scoring system to determine strength of evidence was devised and applied to papers that passed screening. Key studies were identified which achieved the maximum score and more in-depth reviews were conducted for these. We identified 58 studies, including 17 key studies. Strong evidence was found linking a previous bacterial STI, chemsex and increasing numbers of sexual partners to acquisition risk. Condom use, type of sex and new partners were found to have some strength of evidence for this link. SHS attendance and exclusivity had minimal evidence. We recommended that the behaviours/indicators viewed as having strong or some strength of evidence should be considered as screening questions in a more individualised approach to donor selection criteria.

Human immunodeficiency virus, hepatitis C virus and hepatitis B virus incidence in blood donors from 2000 to 2020 in France: Trends and lessons from haemovigilance surveillance

BACKGROUND AND OBJECTIVES

Data from 21 years (2000-2020) of haemovigilance were used to assess human immunodeficiency virus (HIV), hepatitis B virus (HBV) and hepatitis C virus (HCV) incidence rates in repeat blood donors and the occurrence of transfusion-transmitted (TT) viral infections.

MATERIALS AND METHODS

Blood donors who converted for HIV, HCV or HBV markers within serial three-year analysis periods were included. Epidemiological and virological data were retrieved from the national epidemiological donor database and were supplemented with information on blood components and the infection status of recipients of the previous negative donation (D.N-1) of donors who seroconverted.

RESULTS

Incidence rates declined from 1.27 to 0.35/100,000 person-years for HIV, from 0.59 to 0.19 for HCV and from 1.66 to 0.18 for HBV. Risk factors and lookback for 232 HIV, 90 HCV and 74 HBV seroconversions were investigated. The main risk factor identified at post-donation interview was having sex with men (47.8% of males) for HIV and a sexual risk for HCV (30.6%) and HBV (37.1%). The viral loads and sequences were retrospectively tested in 191 HIV, 74 HCV and 62 HBV D.N-1 archived samples. Six (five HBV and one HIV-1) were positive all low viral loads. Two recipients were infected by red blood cells from two HBV seroconverting donors before the introduction of HBV-nucleic acid testing.

CONCLUSION

HIV, HCV and HBV incidence rates in blood donors declined over the two past decades in France. There is a very small risk of a blood component that tests negative entering the blood supply resulting in TT infections, especially after introduction of molecular assays in donor screening.

Virological safety of the UK blood supply in the era of individual risk assessments and HIV PrEP

A more individualised donor selection policy was implemented in the UK in 2021, which replaced the previous 3-month deferral for men who have sex with men (MSM). Other blood services have a variety of policies in place to ensure the virological safety of blood components, ranging from an indefinite ban on MSM, to a defined period of exclusion, or to an individualised risk assessment that is not based on gender or sexual orientation. Justification of these policies should be based on scientific evidence including assessment of lengths of virological window periods, infectious disease epidemiology within donor populations and donation screening assay sensitivities. Developments in molecular technology and assays which can detect both antibodies and antigens in the very early stages of infection have significantly reduced the risk in most developed countries. However, the increasing usage of pre-exposure prophylaxis (PrEP) to prevent acquisition of HIV infection after possible high-risk sexual contact within the UK blood donor population has been recently noted. It has brought with it new diagnostic challenges within blood screening, notably possible non-detection of HIV RNA and serological markers following PrEP use despite potential infectivity. The use of other testing strategies such as detection of HIV DNA and screening for non-declared PrEP usage should be investigated further.

Why some canine and feline blood donors do not make the cut: A cohort study

BACKGROUND

While there has been extensive investigation into the selection and retention of human blood donors, veterinary research in this area is limited. This study aimed to identify the reasons for the rejection and withdrawal of canine and feline blood donors from a blood donation programme.

METHODS

Records of cats and dogs presenting as prospective blood donors and/or donating between 2014 and 2019 were analysed. Reasons for rejection at sign-up were categorised into medical and temperament. Reasons why animals left before retirement age were categorised into medical, temperament and owner related.

RESULTS

Data from 362 dogs and 134 cats were analysed. Cats (20.8%) were more likely to be rejected than dogs (5.2%) at sign-up, mostly due to medical reasons. Both species often left the blood donor service early due to temperament reasons. Owner and medical reasons for leaving early were also common.

LIMITATION

This was a retrospective study with subjective assessment of temperament.

CONCLUSIONS

Inability to donate due to temperament and medical reasons is common. When recruiting blood donors, it should be recognised that a fairly high proportion will not be successful. Owner understanding and motivation are essential to ensure successful selection and retention of donors, which allows amortisation of recruitment costs.

Challenges for the maintaining the microbiological safety of the UK blood supply

The supply of blood, blood products and components in the UK, as elsewhere, is safe, although there is no cause for complacency. Use of blood, blood products and components is not without risk of morbidity and mortality. Transfusion-transmitted infections (TTIs) continue to occur and may severely affect the health and welfare of recipients. As indicated by recent and current inquiries, public interest in these TTIs is huge. The risk of TTI can be mitigated but not abolished. Measures to reduce risk include screening of donors, testing of donations and, where appropriate, treatment of donations. The introduction of newer screening tests might identify some infectious donations but come at a cost, which could exceed a justifiable limit. Thus, the recognition, detection, reporting and investigation of cases of possible TTIs need to be improved. Recipients of blood should understand that, although transfusion in the UK is safe, it is not free of risk and so should be provided with full information so that properly informed consent can be given.

Hepatitis A virus (HAV) RNA detection in Polish blood donors and likely transmissions through blood components during the 2017-2019 epidemic

BACKGROUND

In Poland, hepatitis A virus (HAV) RNA screening was performed in plasma for fractionation usually immediately before shipment.

OBJECTIVE

Our goal was to study epidemiology, rate of transfusion transmitted HAV during epidemic (2017-2019), and viral characteristics of infected plasma donors.

STUDY DESIGN AND METHODS

HAV RNA was tested in 1,866,590 donations from 1,210,423 donors using RT-PCR in mini pools of 96 (MP96) or TMA in MP16. Virological characteristics included RNA level (RL), antibody testing, and sequencing.

RESULTS

Twenty-one HAV infections were identified (1.13/100,000 donations; 95% confidence interval [95% CI]: 0.74-1.72) and (1.73/100,000 donors; 95% CI: 1.35-2.65). The Blood Transfusion Centers were also informed about three donors, who were hospitalized for hepatitis A soon after their blood donation. In addition, we identified a donor, who had reactive result for HAV after receiving HAV vaccination. He tested positive twice 10 days after receiving the first and the second dose. The highest RL was 16 million IU/ml, mean 1,706,905 IU/ml, and median 220 IU/ml. The longest detectable RL lasted for 113 days. HAV-infected donors were seronegative (36%) or IgM positive (64%). We followed up on 12 HAV contaminated blood components issued for transfusion. In two out of seven identified patients viral transmission was confirmed (28.6%).

CONCLUSION

Based on our results, we propose a 6 month deferral after HAV infection and 14 days post HAV vaccination. The infectivity rate was below 30%. The HAV RNA testing could be considered as an additional safeguard against HAV transmission at the time of increased incidence of HAV infections in the general population.

Comparative evaluation of four commercial analyzers for the serological screening of hepatitis A, B, C and HIV

BACKGROUND

Independent evaluations that deploy clinical patient samples are important in assessing the performance of commercial tests used for serological screening of viral hepatitis and HIV in clinical laboratories.

OBJECTIVES

We compared the analytical performance of Abbott Architect i2000SR, Abbott Alinity i, DiaSorin Liaison XL, and Siemens Atellica for the following analytes: anti-HAV IgG/anti-HAV total, anti-HAV IgM, HBsAg, anti-HBc IgM, Anti-HBc, HBeAg, anti-HBe, anti-HBs, anti-HCV, and HIV Ag/Ab. In addition, anti-HBc IgM, HBeAg, and anti-HBe were evaluated for Abbott Architect, Abbott Alinity and DiaSorin Liaison.

STUDY DESIGN

Pseudonymized clinical serum specimens (N = 98-200 for each analyte) were selected for the analysis according to their reactivity on the Abbott Architect. The results were compared against Abbott Architect and against consensus.

RESULTS

A generally high agreement was observed between the tests. Abbott Alinity had the lowest anti-HAV IgG/total specificity (75.9% against Abbott Architect and 83.0% against consensus). The comparatively low sensitivity of Siemens Atellica (78.2%), Abbott Alinity (87.5%) and DiaSorin Liaison (89.3%) for anti-HAV IgM against Abbott Architect may reflect a higher false-positive rate of Abbott Architect. Particular variation was observed in the sensitivity values of anti-HBc, HBsAg and HIV Ag/Ab between the test methods. DiaSorin Liaison anti-HBs gave consistently higher values as compared to the other tests.

CONCLUSIONS

The serodiagnostic methods for HIV and viral hepatitis of Abbott Architect, Abbott Alinity, DiaSorin Liaison, and Siemens Atellica performed well in comparison with each other. The observed differences between the tests will provide useful information for clinical laboratories in planning their workflows for screening and confirmation.

Estimating the epidemiology of chronic Hepatitis B Virus (HBV) infection in the UK: what do we know and what are we missing?

Background: HBV is the leading global cause of cirrhosis and primary liver cancer. However, the UK HBV population has not been well characterised, and estimates of UK HBV prevalence and/or incidence vary widely between sources. We aimed to i) extract and summarise existing national HBV prevalence estimates, ii) add a new estimate based on primary care data, and; iii) critique data sources from which estimates were derived. Methods: We undertook a narrative review, searching for national estimates of CHB case numbers in the UK (incorporating incidence, prevalence and/or test positivity data) across a range of overlapping sources, including governmental body reports, publications from independent bodies (including medical charities and non-governmental organisations) and articles in peer-reviewed scientific journals.  An alternative proxy for population prevalence was obtained via the UK antenatal screening programme which achieves over 95% coverage of pregnant women. We also searched for diagnoses of HBV in the QResearch primary care database based on laboratory tests and standardised coding. Results: We identified six CHB case number estimates, of which three reported information concerning population subgroups, including number of infected individuals across age, sex and ethnicity categories. Estimates among sources reporting prevalence varied from 0.27% to 0.73%, congruent with an estimated antenatal CHB prevalence of <0.5%. Our estimate, based on QResearch data, suggests a population prevalence of ~0.05%, reflecting a substantial underestimation based on primary care records. Discussion: Estimates varied by sources of error, bias and missingness, data linkage, and "blind spots" in HBV diagnoses testing/registration. The UK HBV burden is likely to be concentrated in vulnerable populations who may not be well represented in existing datasets including those experiencing socioeconomic deprivation and/or homelessness, ethnic minorities and people born in high-prevalence countries. This could lead to under- or over-estimation of population prevalence estimation. Multi-agency collaboration is required to fill evidence gaps.

Lessons learnt from syphilis-infected blood donors: a timely reminder of missed opportunities

OBJECTIVE

Due to the increased number of syphilis infections diagnosed in the UK and beyond, we reviewed our data on blood donors infected with syphilis in the UK and Ireland between 2016 and 2019.

METHODS

Data were extracted from the surveillance database for all blood donors confirmed positive for syphilis in the UK and Ireland between 2016 and 2019, together with the total number of donations tested during that period. Data on positive cases included gender, age group, reported treatment, symptoms and confirmatory results. All cases were divided into recently acquired within 24 months and past syphilis infection. We also reviewed the information on symptoms characteristic of syphilis reported by blood donors with an untreated syphilis infection during the postdonation discussions.

RESULTS

Screening of 8 246 600 blood donations for treponemal antibodies identified 316 blood donors with confirmed syphilis infection in the UK and Ireland between 2016 and 2019 (1.6 per 100 000 donations). 42% of them (133 of 316) were classed as a recent infection based on their donation testing results, previous donation date and clinical history provided, and they were hence considered potentially infectious. Most of these blood donors (202 of 316, 64%) had not been previously diagnosed or treated for syphilis, although 50 of them reported symptoms consistent with syphilis infection and 19 had been misdiagnosed despite seeking medical help.

CONCLUSIONS

This observational study shows that syphilis infection remains undiagnosed, especially among heterosexual men, and that infectious syphilis is often missed as a differential diagnosis even when donors have presented with genital or oral ulceration, rashes in the genital area and lymphadenopathy. Considering the recent resurgence of syphilis infections in the UK and beyond and our generally expanding sexual networks, it is important to consider syphilis in differential diagnosis even if specific risk factors have not been identified.

Re-assessing the risk of undetected HBV, HCV and HIV in deceased tissue and living surgical bone donors in England

Testing of living surgical bone and deceased tissue donors by NHS Blood and Transplant (NHSBT) has included individual donation (ID) nucleic acid testing (NAT) for HBV, HCV and HIV since 2008. Here, the well-established window period methodology was used to estimate residual risk (RR). Prevalence of viral markers was calculated among both tissue donor populations. Incidence was derived by adjusting incidence among new blood donors by the prevalence ratio for tissue and new blood donors. Residual risk (RR) was calculated as the product of incidence and duration of WP for single donor HBV NAT at 0.058 years (21 days), HCV NAT at 0.008 years (3 days) and HIV NAT at 0.014 (5 days). Between 2013 and 2017, 7886 living surgical bone donors were tested, 16 were positive for markers of HBV, HCV and HIV. HCV had the highest prevalence at 114/100,000 donors. Incidence and RR was highest for HBV at 3.55/100,000-person years and 0.32/100,000 donors (95% CI 0.11/100,000-1.42/100,000). Among 9751 deceased tissue donors tested, 22 were positive for viral markers. HBV had highest prevalence at 174/100,000 donors, and the highest incidence and RR at 8.12/100,000 person years and 0.74/100,000 donors (95% CI 0.08/100,000-2.99/100,000). Using ID NAT, RR of not detecting a HBV, HCV and HIV WP donation among tissue donors is less than 1/100,000 donors. These estimates provide a good starting point for discussing potential risks of viral transmission through tissue transplant with patients.

Hepatitis B infections among blood donors in England between 2009 and 2018: Is an occult hepatitis B infection a risk for blood safety?

INTRODUCTION

Hepatitis B virus (HBV) is one of the most frequent infections identified in blood donors in England and represents an ongoing blood safety risk. We have analyzed markers of HBV infections in blood donors in England between 2009 and 2018 and used these to estimate the likelihood of non-detection of occult HBV infection (OBI).

METHODS

We collected epidemiological, virological, and genotyping information on HBV cases identified in England, 2009-2018. The estimated risk of non-detection and likely transmission of OBI were compared to lookback and transfusion-transmitted infections surveillance data.

RESULTS

Six-hundered and fifty-five HBV-infected blood donors were identified in England during the 10-year period; 598 chronic, 32 acute, and 25 occult HBV infections. However, most donors with chronic and occult infections were born in Eastern Europe, Africa, or Asia (451/544, 83% and 14/24, 58%); acute infections were largely seen in UK-born donors (19/28, 68%). Genotyping of 266 HBV-positive samples revealed five genotypes (A-E), reflecting ethnicity and country of birth. Most OBIs were identified in repeat donors (19/25); lookback data identified a transmission rate of 8.3%. It is estimated that at least 13 potentially infectious donations from donors with OBI remain undetected annually, equating to an overall residual transmission risk of 3.1 per million donations using our current screening strategy of HBsAg screening with HBV nucleic acid testing (NAT) in pools of 24.

CONCLUSIONS

OBI accounted for the majority of the HBV residual risk in England. Further cost-benefit analysis is required to estimate if our current HBV screening strategy should be changed.

The coagulopathy of liver disease: a shift in thinking

The coagulopathy of chronic liver disease causes derangement of the results of traditional laboratory tests. As such, there is an expectation that when undergoing invasive procedures patients with cirrhosis are at increased risk of bleeding. Standard practice is to optimise laboratory values with prophylactic transfusions of platelets, plasma and fibrinogen to reduce perceived bleeding risk. There has been a shift in thinking regarding coagulation in patients with chronic liver disease, whereby a rebalancing of haemostasis occurs with reduction in both procoagulants and anticoagulants. Guidelines for the preprocedural management of patients with chronic liver disease are inconsistent and may not account for this new paradigm. The risk of prophylactic transfusion should be measured against the risk of bleeding while considering the rebalancing of haemostasis. Future management may be guided by whole blood viscoelastic tests or use of thrombopoietin receptor agonists to optimise patients in these scenarios.

Blood donation by men who have sex with men: using evidence to change policy

BACKGROUND

In 2011 in the United Kingdom (UK), excluding Northern Ireland, the deferral of men who have sex with men (MSM) changed from lifetime to 12 months. We describe MSM who donated before and after this to inform further policy reviews.

MATERIALS AND METHODS

Characteristics and sexual behaviours of donors identifying as male from routine surveillance are described. Rates of infections are compared pre- and post-implementation of a 12-month deferral. Donors are compared with screen negative male donors responding to a large-scale survey during 2013/2014.

RESULTS

Comparing the five years pre- and post-change, the rate of confirmed positives for markers of HBV, HCV, HIV and syphilis decreased by 6·9% from 14·1 to 13·1/100 000 donations. The rate of recent infections was unchanged (1·72/100 000). Of 22 776 survey responses identifying as male, MSM disclosed sex between men over 12 months ago giving 99·35% compliance among male donors. Two-thirds of the 72 non-compliant MSM reported one to two partners and one-third had no new partners within 12 months. The most commonly reported reason for non-compliance from MSM both positive and negative for infection was 'not important to declare' (37·2% and 40·7%). Test seeking was rare (9·3% and 2·1%).

CONCLUSION

Compliance with the 12-month MSM deferral policy was very high. The very low rates of infections post-change demonstrated the effectiveness of the policy. These data were an important part of the 2017 review of all sexual behaviour deferrals.

The genotype distribution, infection stage and drug resistance mutation profile of human immunodeficiency virus-1 among the infected blood donors from five Chinese blood centers, 2014-2017

Human immunodeficiency virus-1 (HIV-1) exhibits high diversity and complexity in China, challenging the disease surveillance and antiretroviral therapy. Between July 1, 2014 and January 30, 2017, we investigated the profiles of HIV-1 infection stages, genotype distribution and drug resistance mutations (DRMs) using plasma samples from HIV Western blot (WB) confirmed blood donors from five Chinese blood centers (Chongqing, Guangxi, Luoyang, Mianyang, and Urumqi). HIV pol regions consisted of whole protease and partial reverse transcriptase were genotyped and analyzed for DRMs. Lag-Avidity testing was performed to identify the infection stages. Of the 356 HIV-1 WB positive samples tested by Lag-avidity assay, 19.1% (68/356) were recent infections. Genotyping on 356 amplified sequences presented the subtype distributions as following: CRF07_BC (65.7%), CRF08_BC (7.3%), CRF01_AE (19.1%), B (4.2%), CRF55_01B (3.1%), CRF59_01B (0.3%) and CRF68_01B (0.3%). No significant difference in genotype distribution was observed between recent and long-term infections. 48 DRMs were identified from 43 samples, indicating a drug resistance prevalence of 12.1% (43/356), which include seven protease inhibitors (PIs) accessory DRMs (Q58E, L23I and I84M), two PIs major DRMs (M46I, M46L), seven nucleoside RT inhibitors DRMs (D67N, K70Q, K219R and M184L), and 32 non-nucleoside RT inhibitors DRMs (K103N, V179E, K238N, V179D, E138G, G190E, A98G, Y188D and E138A). In addition, we had also identified CRFs from the 01B subtype including CRF55_01B (3.1%), CRF59_01B (0.3%) and CRF68_01B (0.3%). As an important part of the continuous monitoring of HIV-1 circulating strains among blood donors, our findings were expected to contribute to the comprehensive AIDS control and development of proper diagnostics for HIV-1 in China.

Effect of HIV pre-exposure prophylaxis (PrEP) on detection of early infection and its impact on the appropriate post-PrEP deferral period

INTRODUCTION

HIV antivirals for pre-exposure prophylaxis (PrEP) are known to affect detection of early HIV infection through suppression of viral load and delayed seroconversion. To cover potential delay in HIV detection associated with PrEP use by blood donors in the context of international reductions in sexual activity-based deferral periods, we analysed the available data to determine the appropriate minimum post-PrEP deferral period for blood donation.

MATERIALS AND METHODS

Published cases of incident HIV infection when PrEP use was objectively demonstrable were identified, consisting principally of seroconverters from the Partners PrEP study (a clinical trial of PrEP efficacy). Data were reviewed to determine the impact of PrEP on the detection of HIV RNA, p24 Ag and seroconversion delay.

RESULTS

Nucleic acid testing (NAT) detected early HIV infection in the presence of PrEP prior to or in concordance with serological testing in approximately 90% of cases. Undetectable HIV RNA would rebound to detectable levels within two months of PrEP cessation. PrEP delayed p24 antigen detection and antibody seroconversion by about 7 days.

CONCLUSION

Even when daily PrEP is continued, it is likely that the majority of early HIV infections are detectable by individual donation (ID)-NAT, with p24 Ag or antibody seroconversion occurring conservatively within four weeks of exposure. HIV RNA levels also rebound rapidly in the absence of PrEP. In Australia, a three-month deferral period for blood donation after the last dose of PrEP provides an appropriate safety margin to mitigate the residual risk of transfusion-transmitted HIV.

Attitudes and willingness to donate blood among gay and bisexual men in Australia

BACKGROUND

Men who have sex with men in Australia are currently ineligible to donate blood (are "deferred") for 12 months since last oral or anal sexual contact with another man. In Australia and overseas, there has been limited research on attitudes and perceptions related to blood donation in this population.

STUDY DESIGN AND METHODS

Questions on blood donation histories and attitudes toward the deferral policy were included in the questionnaire of an online prospective cohort of gay and bisexual men (GBM) living in Australia.

RESULTS

In 2018, 1595 GBM responded to the survey. In this sample, 28.7% reported previously donating blood. Among the remaining men who had never donated blood, 64.5% expressed an interest in doing so. Nearly all men indicated they were not willing to abstain from sex with another man for 12 months in order to donate, and the vast majority believed the rule was unfair, too strict, and homophobic. Three-quarters (77.7%) said that if the policy changed, they would likely donate blood. Age and openness about one's sexuality were independently associated with one's willingness to donate blood in the absence of the deferral.

CONCLUSION

There was a high level of willingness and desire to donate blood among GBM. However, rather than abstaining from sex in order to donate, many men comply with the deferral policy and do not donate. A less conservative deferral policy may increase donations from GBM.