Safe supplies: few infections in UK blood and tissue donors.

AIMS/OBJECTIVES: Here, we describe the annual review of the UK blood services' infection surveillance schemes for 2017 (www.gov.uk/government/publications/safe-supplies-annual-review). BACKGROUND: The joint NHS Blood and Transplant/Public Health England Epidemiology Unit was set up in 1995 to ensure that blood and tissue safety is maintained, inform donor selection and testing policy and add to public health knowledge. METHODS: Several surveillance schemes for blood, tissues and bacterial screening collect the numbers of donations tested, reactive and confirmed positive in order to monitor trends in infection rates in donors and calculate residual risk of infection. Investigations of potential transfusion transmissions in recipients are also monitored. RESULTS: In the UK in 2017, the risk of testing not detecting a potentially infectious hepatitis B virus or hepatitis C virus or HIV donation was estimated as less than one in two million donations. One hepatitis A virus and one hepatitis E virus transmission incidents were proven to be transfusion-transmitted by unscreened donations. CONCLUSIONS: The Safe Supplies annual review provides a clear picture of the very low risk associated with blood and tissues in the UK nowadays. In November 2017, the blood services for England, Wales and Scotland implemented recommendations to reduce the deferrals for higher risk sexual behaviour from 12 to 3 months. The surveillance schemes are adapted to remain fit for purpose as testing and donor selection change.

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.

Getting personal with blood donors - the rationale for, methodology of and an overview of participants in the UK blood donor survey.

OBJECTIVE: To design and pilot a survey of UK blood donors to assess, on a large scale, their understanding of and compliance with the donor selection guidelines (DSG). BACKGROUND: Compliance with the DSG is important for maintaining blood safety, however, little is currently known about the extent of this among UK donors. MATERIALS AND METHODS: The online, unlinked survey was based on the donor health check form with a focus on behaviours associated with blood borne infections, sexual contact, drug use and travel. The survey materials were reviewed by a donor focus group and the survey was piloted among 2982 UK donors. Percentage responses were calculated, complaints monitored and answers to questions reviewed. The survey went live in 2013; 225 091 donors were invited via email to participate followed by two reminders. RESULTS: The survey was well received by the focus group, with little concern about the sensitive and personal questions. Their feedback led to important refinement in the survey materials. In the pilots, 21·0% (627/2982) responded, a reminder was necessary to achieve this. Among responders, there was evidence of non-compliance and test seeking behaviour, and no evidence that intention to donate again was affected. In the live survey, 29% (65 439) responded; responders were generally representative of donors overall. CONCLUSION: A large scale survey of donor compliances is feasible, acceptable and effective in ascertaining appropriate information; involving donors and the blood services in the development stages through a focus group and pilots was important to achieve this.

The risk of transfusion-transmitted HIV from blood donations of men who have sex with men, 12 months after last sex with a man: 2005-2007 estimates from England and Wales.

The risk of transfusion-transmitted HIV infection under (i) permanent exclusion and (ii) 12-month deferral of MSM in England and Wales during 2005-2007 was estimated. Assuming equal compliance with both scenarios, estimated risk under a 12-month deferral (0.228/million donations [range 0·168-0·306/million donations]) was only marginally greater (0·5%) than that under lifetime exclusion (0·227/million donations [range 0·157-0.318/million donations]), with one extra-HIV infectious donation every 455 years. Poorer compliance of MSM with a 12-month deferral would be expected to increase the estimated risk, whereas improved compliance could decrease risk by up to 29·1%.

A re-evaluation of the risk of transfusion-transmitted HIV prevented by the exclusion of men who have sex with men from blood donation in England and Wales, 2005-2007.

BACKGROUND AND OBJECTIVES One component of the rationale for lifetime exclusion of men who have sex with men (MSM) from blood donation in the UK is the probable reduction in the risk of transfusion-transmitted HIV; this exclusion has recently been questioned. MATERIALS AND METHODS Data about HIV in blood donors and MSM were analysed to estimate the risk of infectious donations entering the blood supply under different scenarios of donor selection criteria (and donor compliance) for MSM and a heterosexual group with increased risk of HIV. RESULTS In 2005-2007, a change from lifetime exclusion of MSM to 5-year deferral or no deferral increased the point estimate of HIV risk by between 0·4% and 7·4% depending on compliance with the deferral (range -4% to 15%) and 26·5% (range 18% to 43%) respectively. A change from a 12-month deferral of the high-risk heterosexual group to lifetime exclusion reduced the estimated risk by about 7·2% (range 6% to 9%). Each point estimate was within the probable range of risk under the current criteria. CONCLUSION If prevalence is the only factor affected by a reduced deferral, then the increased risk of HIV is probably negligible. However, the impact of a change depends on compliance; if this stays the same or worsens, the risk is expected to increase because of more incident infections in MSM who donate blood. The risk of transfusion-transmitted HIV could probably be reduced further by improving compliance with any exclusion, particularly after recent risk behaviours.

Recruiting individuals into the HTLV cohort study in the United Kingdom: clinical findings and challenges in the first six years, 2003 to 2009.

Human T-lymphotropic virus (HTLV) infection is rare in the United Kingdom (UK) and few studies are available worldwide. Following introduction of blood donation testing in 2002, a cohort of individuals could be identified and prospectively recruited to describe progression and onset of disease. Here we describe baseline characteristics of participants, and evaluate recruitment into the UK HTLV National Register over the first six years, from July 2003 to June 2009. A multicentre cohort study recruited participants from the UK blood services (recipients and donors) and specialist HTLV clinics. Almost half of the 148 participants recruited were blood donors, nine were blood transfusion recipients, 40 contacts and 29 clinic attendees (nine asymptomatic and 20 symptomatic). Most participants were HTLV-1 positive (n=115); 11 had HTLV-2 and 22 were HTLV-negative. Baseline self-completion questionnaires were received for 83%. The most commonly reported condition was a past operation/serious illness (69%). Twenty-six participants reported four or more possible signs/symptoms of HTLV-1-associated myelopathy/tropical spastic paraparesis. Recruitment into a study of a rare, long-term infection is challenging. This cohort will enable descriptions of HTLV-associated disease progression amongst people recruited from varying sources; it is the first prospective study of its kind in Europe.

The introduction of anti-HTLV testing of blood donations and the risk of transfusion-transmitted HTLV, UK: 2002-2006.

The objectives of the study were to describe the introduction of testing blood donations for antibodies to human T-cell lymphotropic virus (anti-HTLV) and to determine the risk of HTLV potentially infectious donations entering the UK blood supply. The rationale for testing was based on (i) evidence of transmission through transfusion in the UK, (ii) the serious nature of HTLV I-associated morbidity and (iii) evidence of infection in UK blood donors. From mid-2002, all blood donations made at UK blood centres were tested in pooled samples using Abbott-Murex HTLV I/II GE 80/81 enzyme immunoassay (EIA). Surveillance data were used to calculate the incidence and prevalence of anti-HTLV and derive estimates of risk. Between August 2002 and December 2006, 106 donations were confirmed positive for anti-HTLV (95 anti-HTLV I and 11 anti-HTLV II). Prevalence was 10-fold higher among donations from new donors than repeat (4.0 and 0.42 per 100 000 donations), and only one repeat donor had evidence of seroconversion. The risk of an HTLV I potentially infectious donation entering the UK blood supply was estimated at 0.11 per million donations (95% confidence interval 0.06 to 0.18). The current very low observed incidence and prevalence among blood donors reflect the very low estimated risk of an HTLV I-positive donation entering the UK blood supply. A change in either the epidemiology of HTLV in UK blood donors or the length of the window period of the test should prompt further review of the risk and a reassessment of anti-HTLV testing in the UK.

Infections detected in English surgical bone and deceased donors (2001-2006) and estimated risk of undetected hepatitis B and hepatitis C virus.

BACKGROUND AND OBJECTIVES: Infections can be transmitted through donated tissue products, such as femoral heads. Here we describe infections detected through microbiological testing of English surgical bone and deceased donors (2001-2006) and estimate the residual risk of infection. MATERIALS AND METHODS: Data on infected tissue donors identified by NHS Blood and Transplant (NHSBT) were collected through the NBS/Health Protection Agency Infection Surveillance programme. The blood donor model for estimating risk was adapted for tissue donors. Incidence among surgical bone donors was derived from new blood donor data and estimates of residual risk presented for surgical bone donors only. RESULTS: Fifty-seven surgical bone and four deceased donors were identified with 60 and five infections, respectively, during the 6 years. Syphilis was the most common infection detected, with no human T-lymphotropic virus infections and one HIV infection in a deceased donor. Hepatitis B virus, hepatitis C virus and syphilis prevalence was higher among surgical bone and deceased donors than new blood donors for the same period. The overall estimated risk of undetected hepatitis B and hepatitis C virus among surgical bone donors (2001-2006) on initial screening was 0.426 and 0.048 per 100 000 donors, respectively. Testing a follow-up sample made these risks almost negligible. CONCLUSION: The prevalence of infections was low among English tissue donors. Risk estimates were higher for surgical bone donors on first screening than among new blood donors. However, the probability of an infectious donation entering the tissue supply became negligible after obtaining a follow-up sample 6 months post-donation and were well below that of new blood donors.

Chlorinated dibenzo-p-dioxin and dibenzofuran concentrations in beef animals from a feeding study.

Four calves were fed polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans for 120 days at levels somewhat higher than what may be found in forage near some waste incinerators and manufacturing plants. Four calves were fed identical diets but without the chemicals. Using bioelectrical impedance measurements of total body fat, 30-50% of the dosed 2,3,7,8-TCDD, 1,2,3,7,8-PeCDD, and 2,3,4,7,8-PeCDF was estimated to be retained by the animals. Although these same congeners were bioconcentrated in adipose tissue (BCF approximately 10), consumer products such as ribeye showed concentrations less than what were found in the animal feed (BCF approximately 0.1). Distribution of the dioxins and furans into various lipid compartments appeared to be rather uniform in back fat, perirenal fat, and ribeye for tetra to hexa congeners. Ribeye, serum, and liver lipids had higher concentrations of the higher chlorinated congeners, due in part to not reaching a steady state. An unexpected source of dioxin and furan contamination was discovered during the experiment, resulting in the control animals having concentrations of some congeners that were equal to or in some cases greater than those of the dosed animals. Pentachlorophenol-treated wood components in the pole barn where the feeding experiment was conducted were found to have contributed to the animals' exposure.

Propachlor-S-glutathione metabolism by kidneys and ureters of calves.

Six anesthetized 2- to 21-d-old male Guernsey calves weighing 28 to 61 kg were used in experiments in which either the left kidney was perfused, via the left renal artery, or the left ureter was perfused with metabolites of propachlor (2-chloro-N-acetylacetanilide, a herbicide). The glutathione conjugate of propachlor (2-S-glutathionyl-N-acetylacetanilide) was metabolized by both kidney and ureter to the cysteine conjugate (2-S-cysteinyl-N-isopropylacetanilide). The glutathione conjugate was not metabolized to the mercapturic acid conjugate (2-S-[N-acetyl]cysteinyl-N-isopropylacetanilide). When the mercapturic acid conjugate of propachlor was presented to the kidney, it was eliminated in urine. First-pass metabolism and elimination of the glutathione conjugate by the kidney was 16% of the dose, whereas first-pass elimination of the mercapturic acid was 33%. Absorption of the glutathione conjugate of propachlor, or its metabolites, or of glycine by the ureter was nil. The bovine species may be unable to form mercapturic acids from glutathione conjugates of some xenobiotics, which may make cattle more easily poisoned by these xenobiotics than chickens, pigs, and rats.

[14C]monensin balance in bile-fistulated ponies.

To measure absorption of monensin or its metabolites and its elimination from the body, [14C]monensin sodium was given orally (1 mg/kg body wt) to two bile-fistulated ponies and iv (8.7 mg) to one bile-fistulated pony. For one orally-dosed pony, 4.7% of the 14C was eliminated in bile, 52% in feces, .7% in urine and 33% remained in the gastrointestinal (GI) tract after 3 d. Total 14C recovery was 90%. For the other orally-dosed pony, 18.3% of the 14C was eliminated in bile, 69% in feces, 1.7% in urine and 7% remained in the GI tract after 4 d. Total 14C recovery was 98%. For the iv-dosed pony, 72% of the 14C was eliminated in bile, .5% in feces, 4.9% in urine and 15% remained in the GI tract after 23 h. Total 14C recovery was 96%. Maximum rate of 14C elimination in feces from the orally-dosed ponies occurred on the third and fourth days, and the maximum rate of biliary elimination occurred between 16 and 24 h for one pony and 48 and 56 h for the other. For the iv-dosed pony, 14C became immeasurable in plasma within 12 h after dosing and appeared in bile within 30 min, with maximum biliary concentration occurring at about 1 h. Monensin accounted for a minimum of 19% of the 14C in a 56- to 72-h sample of feces for one orally-dosed pony and a minimum of 25% of the 14C in feces from the same time period for the other.(ABSTRACT TRUNCATED AT 250 WORDS)

A comparison study of vecuronium bromide and atracurium besylate for rapid sequence induction.

Rapid sequence induction is necessary in emergency surgical operations to lessen the chance of aspiration of stomach contents. Succinylcholine usually is the relaxant of choice, because of its rapid onset. However, succinylcholine has side effects which may result in potentially life-threatening conditions. The purpose of this study was to compare two short-acting non-depolarizing muscle relaxants-vecuronium and atracurium, using the priming principle, with a depolarizing muscle relaxant, succinylcholine. The comparison may determine if a more suitable method for rapid sequence induction can be identified. Conditions at intubation and at the time to 80-90% neuromuscular blockade were evaluated. Subjects were intubated when the train of four revealed an 80-90% twitch depression. In Group I, the control group using succinylcholine, the mean time to 80-90% neuromuscular block was 74.8 seconds. In Group II subjects, who had received vecuronium, the mean time was 149.4 seconds. Subject in Group III, who received atracurium, had a mean time of 163.7 seconds. There was statistical significance within all three groups (ANOVA, p less than 0.01). Group I subjects showed a significantly faster time to 80-90% neuromuscular block when compared with subjects in Group II and III, but no difference in the time to 80-90% block was revealed between Group II and Group III subjects. Conditions for intubation at 80-90% neuromuscular blockade were the same for all three groups. It was concluded that the administration of vecuronium and atracurium using the priming principle did not allow onset times similar to succinylcholine and that the intubating conditions were similar among all three groups at 80-90% neuromuscular blockade.