Dissecting the decline of hepatitis C in first-time donors in England and Wales.

BACKGROUND AND OBJECTIVES: The rate of confirmed hepatitis C virus (HCV) cases, in first-time donors, is much lower in 2015 than 20 years ago. We investigate reasons for the decline. MATERIALS AND METHODS: HCV rates were analysed by gender and birth cohort for 1996 to 2015 and ethnic group for 2006 to 2015. Variables for confirmed positive cases were compared for two ten-year periods (1996 to 2005 and 2006 to 2015) including genotyping data for 2006 to 2015. RESULTS: There were 2007 confirmed HCV cases identified between 1996 and 2015. The rate per 100 000 donations fell from 78·6 in 1996 to 26·9 by 2015. By birth cohort, HCV rates were highest in donors born in the 1950s and 1960s who contributed a decreasing proportion of first-time donors. Between 2006 and 2015, there was no significant decline in HCV rate. The HCV-positive donor profile has changed in the last 10 years with increased proportions of younger donors, donors born abroad and decreased reported injecting drug use. Genotype 1a remains predominate, but genotype 1b has increased associated with this change in birth cohort and ethnicity. CONCLUSION: The decline in number and rate of confirmed HCV-positive first-time donors is mainly due to a decrease in first-time donors born before 1970, with the highest rate of HCV. However, the decline has slowed and the profile of HCV-positive first-time donors is changing. A better understanding of behaviour and sources of HCV in younger and ethnic minority donors are needed.

Targeting of blood safety measures to affected areas with ongoing local transmission of malaria.

An outbreak of locally acquired Plasmodium vivax malaria in Greece started in 2009 and peaked in 2011. Targeting of blood safety measures to affected areas with ongoing transmission of malaria raised questions of how to define spatial boundaries of such an area and when to trigger any specific blood safety measures, including whether and which blood donation screening strategy to apply. To provide scientific advice the European Centre for Disease Prevention and Control (ECDC) organised expert meetings in 2013. The outcomes of these consultations are expert opinions covering spatial targeting of blood safety measures to affected areas with ongoing local transmission of malaria and blood donation screening strategy for evidence of malaria infection in these areas. Opinions could help EU national blood safety authorities in developing a preventive strategy during malaria outbreaks.

Detection of malarial DNA in blood donors--evidence of persistent infection.

BACKGROUND AND OBJECTIVES: The English transfusion service has screened donations from malaria-risk donors for malarial antibodies for over 10 years. The donor population includes migrants from many malaria-endemic countries and, from our experiences with post-transfusion malaria, some of these may remain parasitaemic and need clinical review. MATERIALS AND METHODS: Malarial antibody screen-reactive donations with serological evidence of malaria identified by the reference laboratory were further investigated for the presence of malarial DNA. RESULTS: Malarial DNA was found in 14 of 1955 samples investigated; three P. falciparum, five P. vivax, three P. ovale, two P. malariae and one dual parasitaemia P. falciparum/P. malariae. All of these were donors whose malaria risk was residency rather than travel. CONCLUSION: Malarial parasitaemia in healthy donors occurs, and donor malaria-risk strategies must take into account the possibility of such donors presenting. Countries not utilizing malarial antibody screening should consider carefully the collection of donations from donors previously resident in endemic countries; temporary deferral is insufficient.

Effective serological and molecular screening of deceased tissue donors.

A comprehensive and effective screening programme is essential to support the banking of tissues from deceased donors. However, the overall quality of the samples obtained from deceased donors, quantity and condition, is often not ideal, and this may lead to problems in achieving accurate and reliable results. Additionally a significant percentage of referrals are still rejected upon receipt as unsuitable for screening. We are actively involved in improving the overall quality of deceased donor screening outcomes, and have specifically evaluated and validated both serological and molecular assays for this purpose, as well as developing a specific screening strategy to minimise the specificity issues associated with serological screening. Here we review the nature and effectiveness of the deceased donor screening programme implemented by National Health Service Blood and Transplant (NHSBT), the organisation with overall responsibility for the supply of tissue products within England. Deceased donor screening data, serological and molecular, from August 2007 until May 2012 have been collated and analysed. Of 10,225 samples referred for serology screening, 5.5 % were reported as reactive; of 2,862 samples referred for molecular screening, 0.1 % were reported as reactive/inhibitory. Overall 20 % of the serological and 100 % of the molecular screen reactivity was confirmed as reflecting true infection. The use of a sequential serology screening algorithm has resulted in a marked reduction of tissues lost unnecessarily due to non-specific screen reactivity. The approach taken by NHSBT has resulted in the development of an effective and specific approach to the screening of deceased tissue donors.

Qualification of serological infectious disease assays for the screening of samples from deceased tissue donors.

Whilst some of the assays used for serological screening of post-mortem blood samples from deceased tissue donors in some countries have been specifically validated by the manufacturer for this purpose, a significant number of those currently in use globally have not. Although specificity has previously been considered a problem in the screening of such samples, we believe that ensuring sensitivity is more important. The aim of this study was to validate a broader range of assays for the screening of post-mortem blood samples from deceased tissue donors. Six microplate immunoassays currently in use within National Health Service Blood and Transplant (NHSBT) for the screening of blood, tissue and stem cell donations were included. Representative samples from confirmed positive donors were titrated in screen negative post-mortem samples in parallel with normal pooled negative serum to determine if there was any inhibition with the post-mortem samples. There were no significant differences seen (P < 0.005) between the dilution curves obtained for the positive samples diluted in post-mortem samples and normal pooled sera. Although small numbers of samples were studied, it can be surmised that the post-mortem blood samples from deceased tissue donors, collected according to United Kingdom guidelines, are a suitable substrate for the assays evaluated. No diminution of reactivity was seen when dilution with sera from deceased donors was compared to dilution using pooled serum from live donors. In the absence of genuine low titre positive post-mortem samples, the use of samples spiked with various levels of target material provides a means of qualifying serological screening assays used by NHSBT for the screening of post-mortem blood samples from deceased tissue donors.

The serological screening of deceased tissue donors within the English Blood Service for infectious agents--a review of current outcomes and a more effective strategy for the future.

BACKGROUND AND OBJECTIVES: The overall effectiveness of the NHSBT screening programme for infectious agents in deceased tissue donors is examined and evaluated in terms of current outcomes and how to improve upon these outcomes. MATERIALS AND METHODS: The screening results and any subsequent confirmatory results from a total of 1659 samples from NHSBT deceased donors referred to NTMRL for screening for infectious agents were included in the analysis. RESULTS: Overall 1566/1659 (94.4%) of the samples were screen negative. A total of 93 were repeat reactive on screening for one or more of the mandatory markers screened for, of which only 12 (13%) were subsequently confirmed to be positive on confirmatory testing. The majority of the repeat reactive samples were demonstrating non-specific reactivity with the screening assays in use. CONCLUSION: Overall, the NHSBT screening programme for infectious agents in deceased tissue donors is very effective with a relatively low overall loss of donors because of non-specific reactivity. However, unnecessary loss of tissue products is not acceptable, and although this programme compares favourably with the outcomes of other such programmes, the confirmatory results obtained demonstrate both the need and the potential for improving the outcomes. This is particularly important as one donor may donate more than one product, and can be achieved very easily with a change to the screening algorithm followed, using the confirmatory data obtained to support and validate this change. CONTENTS SUMMARY: Critical analysis of the NHSBT screening programme for infectious agents in deceased tissue donors and a strategy involving the design and use of a different screening algorithm to improve these outcomes.

Lot release testing of serological infectious disease assays used for donor and donation screening.

BACKGROUND AND OBJECTIVES: Monitoring of the ongoing performance of infectious disease screening assays is a critical part of any donation screening programme. Although assay sensitivity is formally evaluated prior to implementation, it is essential that this level of performance is maintained from lot-to-lot. In 2002, National Health Service Blood and Transplant developed and implemented a formal system for the lot release testing of serology infectious disease screening assays. MATERIALS AND METHODS: Lot release panels were prepared for each of the serological screening markers. They each comprise 10-15 members and include both genuine low-titre and diluted high-titre materials. For each panel member, a minimum reactivity is expected, based upon the formal sensitivity evaluation of each assay. All new lots of the screening assays used are assessed prior to supply of the lot to the organization. RESULTS: Since 2002, a total of 887 different lots of the serology screening assays used have been supplied. Of these, 876 (98.8%) passed lot release and were authorized for supply to the organization. Eleven lots (1.2%) were failed because the lots did not meet the release criteria or were unsuitable for some other reason. CONCLUSION: The lot release system has proved to be effective in objectively assessing assay performance to ensure that there is no significant lot-to-lot variation such that the performance of the assay may fall below that originally determined at evaluation. The few assays that have failed lot release did have proven performance issues that were subsequently accepted by the manufacturers. CONTENTS SUMMARY: Description of the Lot Release Testing system for serology infectious disease screening assays in use within NHSBT with a critical analysis and review of the data generated in the 7 years that the system has been in use.

HIV screening reactivity due to donor participation in HIV vaccine trials.

We report two instances of human immunodeficiency virus (HIV) serological screening reactivity in blood donations which were subsequently determined to be due to donor participation in HIV vaccine trials. Both donations were screen reactive with atypical patterns on confirmation; no definitive conclusion could be given for either donor. Subsequent questioning identified that both donors had been involved in HIV vaccine trials. In both cases the screening and confirmation identified the presence of HIV antibodies, although vaccine induced. While clinical trials of vaccines are important, the implications of some need careful consideration if they are not to adversely impact other areas of healthcare.

Comparative analyses of whole genome sequences of Leishmania infantum isolates from humans and dogs in northeastern Brazil.

The genomic sequences of 20 Leishmania infantum isolates collected in northeastern Brazil were compared with each other and with the available genomic sequences of 29 L. infantum/donovani isolates from Nepal and Turkey. The Brazilian isolates were obtained in the early 1990s or since 2009 from patients with visceral or non-ulcerating cutaneous leishmaniasis, asymptomatic humans, or dogs with visceral leishmaniasis. Two isolates were from the blood and bone marrow of the same visceral leishmaniasis patient. All 20 genomic sequences display 99.95% identity with each other and slightly less identity with a reference L. infantum genome from a Spanish isolate. Despite the high identity, analysis of individual differences among the 32 million base pair genomes showed sufficient variation to allow the isolates to be clustered based on the primary sequence. A major source of variation detected was in chromosome somy, with only four of the 36 chromosomes being predominantly disomic in all 49 isolates examined. In contrast, chromosome 31 was predominantly tetrasomic/pentasomic, consistent with its regions of synteny on two different disomic chromosomes of Trypanosoma brucei. In the Brazilian isolates, evidence for recombination was detected in 27 of the 36 chromosomes. Clustering analyses suggested two populations, in which two of the five older isolates from the 1990s clustered with a majority of recent isolates. Overall the analyses do not suggest individual sequence variants account for differences in clinical outcome or adaptation to different hosts. For the first known time, DNA of isolates from asymptomatic subjects were sequenced. Of interest, these displayed lower diversity than isolates from symptomatic subjects, an observation that deserves further investigation with additional isolates from asymptomatic subjects.

Is there a link between breast cancer and abortion: a review of the literature.

The hormonal changes that take place in pregnancy cause breast tissue to proliferate and differentiate. Abortion interrupts this process and may leave the proliferated, undifferentiated breast tissue at higher risk of carcinogenesis. This review explains the supposed difference in effects of induced and spontaneous abortion upon the breast tissue and examines the literature for a link with breast cancer. Additional subcategories examined include parity, number of abortions, gestation, and maternal age at abortion. A comparison of retrospective and prospective studies is made and possible sources of bias are identified. There is no evidence to support a link between spontaneous abortion and breast cancer. Absence of a link with induced abortion is less clear, and further research should concentrate on investigating any relationship. We suggest that prospective research is used, with point of entry at first termination.

Clomipramine treatment of trichotillomania: a follow-up report on four cases.

Four consecutive patients treated for trichotillomania (hair pulling) with clomipramine reported initially dramatic reductions in symptoms. However, three of the four patients had relapsed completely at 3-month follow-up, although all four were still taking previously effective levels of the drug. The fourth patient relapsed for about 2 weeks but regained initial treatment benefits. Implications for the treatment of trichotillomania are discussed.

The effects of cage size and complexity on the behaviour of captive common marmosets, Callithrix jacchus jacchus.

Conditions of captivity of primates used in biomedical research may have deleterious effects on the welfare of the animals and consequently on the reliability of the research. We investigated the effects of cage size and cage complexity, two fundamental characteristics of captive conditions, on the behaviour of the common marmoset (Callithrix jacchus jacchus). We found an increase in the general level of activity and significant variation in the frequencies of specific behaviours with an increase in cage size and also with cage complexity. Stereotyped behaviours, which occurred in the small cages, were never exhibited in the large cages. The effect of the novelty of the changed conditions was also assessed and found to be significant for some behaviours. We also measured the time taken to capture an animal, a task frequently performed by the animal technician, under the various cage conditions. Capture time increased significantly in the larger cages, but the overall effect of the changes to the marmosets' housing conditions on the animal technician's work was not regarded as substantial. We conclude that the welfare of captive marmosets is enhanced by the provision of larger and more complex cages, and that such cages do not significantly affect the efficiency of the research laboratory.

Identification of the most informative regions of the mitochondrial genome for phylogenetic and coalescent analyses.

Analysis of complete mitochondrial genome sequences is becoming increasingly common in genetic studies. The availability of full genome datasets enables an analysis of the information content distributed throughout the mitochondrial genome in order to optimize the research design of future evolutionary studies. The goal of our study was to identify informative regions of the human mitochondrial genome using two criteria: (1) accurate reconstruction of a phylogeny and (2) consistent estimates of time to most recent common ancestor (TMRCA). We created two series of datasets by deleting individual genes of varied length and by deleting 10 equal-size fragments throughout the coding region. Phylogenies were statistically compared to the full-coding-region tree, while coalescent methods were used to estimate the TMRCA and associated credible intervals. Individual fragments important for maintaining a phylogeny similar to the full-coding-region tree encompassed bp 577-2122 and 11,399-16,023, including all or part of 12S rRNA, 16S rRNA, ND4, ND5, ND6, and cytb. The control region only tree was the most poorly resolved with the majority of the tree manifest as an unresolved polytomy. Coalescent estimates of TMRCA were less sensitive to removal of any particular fragment(s) than reconstruction of a consistent phylogeny. Overall, we discovered that half the genome, i.e., bp 3669-11,398, could be removed with no significant change in the phylogeny (p(AU)=0.077) while still maintaining overlap of TMRCA 95% credible intervals. Thus, sequencing a contiguous fragment from bp 11,399 through the control region to bp 3668 would create a dataset that optimizes the information necessary for phylogenetic and coalescent analyses and also takes advantage of the wealth of data already available on the control region.

The systematic monitoring of transfusion microbiology test kit performance.

The Transfusion Microbiology Test Systems Monitoring Group (TMTSMG) was established as a National Blood Service (NBS) working group to monitor the performance of the microbiology screening assays used within the NBS Testing Laboratories. The group's primary objective was to ensure that technical performance (especially sensitivity, specificity and wastage) remains consistent with that established during validation. This includes the identification and investigation of significant variation in performance and any untoward incidents. The group is also responsible for optimizing transfusion microbiology working practice across the NBS through nationally agreed standards and procedures. Over the past 9 years, a total of 44 assays from 15 suppliers have been monitored. Five assays have been withdrawn from use as a result of identified poor performance; two hepatitis B virus surface antigen assays owing to poor sensitivity, two syphilis agglutination assays with nonspecific (false) reactive rates sustained above contract limits and one human cytomegalovirus antibody assay that persistently failed the manufacturer's quality control criteria. This approach has enabled the differentiation of genuine kit performance issues from 'natural variation' in kit performance, and local instrumentation or training issues. The NBS has been able to address the issues with suppliers much earlier and resolve minor issues before they became major problems. In addition, a lot release system has been developed and implemented, comprising a formal, centralized initial scientific assessment of each new manufacturer's lot, followed by 'delivery acceptance' testing at each site. This system helps to ensure that the evaluated minimum sensitivity and specificity of the assays is maintained from 'lot to lot'.