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BACKGROUND: The two Canadian blood suppliers, Canadian Blood Services and Héma-Québec, removed the time-based deferral for men who have sex with men and adopted criteria assessing sexual risk behaviors. We report the impact of these changes on the safety and adequacy of the Canadian blood supply. STUDY DESIGN AND METHODS: Since 2022, all donors are asked if (1) they have had a new partner and (2) more than one sexual partner in the last 3 months. Donors answering yes to either question are asked if they had anal sex in the last 3 months; if yes, they are deferred for 3 months. We followed HIV rates for the 18 months before and 14 (Héma-Québec) or 18 months (Canadian Blood Services) post-implementation and interviewed HIV-positive whole blood donors. We assessed the number and characteristics of whole blood donors answering yes to the two first questions with or without deferral. RESULTS: There were four HIV-positive donations out of 1,492,355 donations pre-implementation and four out of 1,447,772 post-implementation (0.27/100,000 vs. 0.28/100,000, p = 1.00). Post-implementation, one HIV-positive donor was non-compliant with multiple criteria, no risk factors were identified in the others. 3.2% of donors answered yes to questions (1) and/or (2); 0.17% were deferred for a new partner and/or more than one partner and anal sex. Deferral rates were highest in first time, younger donors, and similar in males and females. CONCLUSION: Implementation of sexual risk behavior donor screening resulted in unchanged HIV rates to date and a manageable deferral rate.
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Donantes de Sangre , Selección de Donante , Conducta Sexual , Humanos , Masculino , Donantes de Sangre/estadística & datos numéricos , Canadá , Femenino , Adulto , Infecciones por VIH/epidemiología , Infecciones por VIH/diagnóstico , Asunción de Riesgos , Persona de Mediana Edad , Tamizaje Masivo , Homosexualidad MasculinaRESUMEN
BACKGROUND: Combining pathogen reduction technology (PRT) with blood screening may alleviate concerns over the risk of transfusion-transmitted infections (TTI) and support changes in blood donor selection to potentially increase blood availability. This study aimed to estimate the residual risk of human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) transfusion-transmission in Canada after implementing PRT, while eliminating deferrals for sexual risk behaviors. STUDY DESIGN AND METHODS: A probabilistic approach that combined Bayesian networks with Monte Carlo simulations was used to estimate the risk of transfusing HIV-, HBV-, or HCV-contaminated blood components. Different scenarios were considered to compare the current residual risk after PRT implementation, with and without donor deferral criteria for sexual risk behaviors. Donor profiles and blood component outcomes were simulated based on a literature review including the prevalence and incidence of HIV, HBV, and HCV in the Canadian blood donor population; the use of current blood screening assays; and HIV, HBV, and HCV blood donor viral loads. RESULTS: In the universal PRT scenario (i.e., with PRT/without deferral criteria), the estimated risks of HIV, HBV, and HCV transmission were significantly lower than those in the currently observed scenario (i.e., without PRT/with deferral criteria). CONCLUSIONS: This risk model suggests that PRT for platelets and plasma (and eventually for RBCs when available) significantly reduces the residual risks of HIV, HBV and HCV transfusion-transmission and could enable the removal of blood donor deferral criteria for sexual risk behaviors.
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Donantes de Sangre , Selección de Donante , Infecciones por VIH , Hepatitis B , Hepatitis C , Conducta Sexual , Humanos , Hepatitis B/prevención & control , Hepatitis B/transmisión , Hepatitis B/epidemiología , Hepatitis C/transmisión , Hepatitis C/prevención & control , Hepatitis C/epidemiología , Infecciones por VIH/transmisión , Infecciones por VIH/prevención & control , Selección de Donante/métodos , Canadá/epidemiología , Asunción de Riesgos , Reacción a la Transfusión/prevención & control , Simulación por Computador , Seguridad de la Sangre , Método de Montecarlo , Femenino , Teorema de Bayes , Masculino , Infecciones de Transmisión Sanguínea/prevención & control , Infecciones de Transmisión Sanguínea/transmisiónRESUMEN
BACKGROUND: In Canada, as many as 24% of mothers are deferred from cord blood (CB) donation due to risk factors for Zika virus (ZIKV). However, the ZIKV epidemic has waned considerably since 2016, and there has not been any report of ZIKV transmission by CB transplantation, which questions this policy. Thus, we performed an analysis of the risk of introducing ZIKV in the CB supply maintained by Héma-Québec (HQ) and Canadian Blood Services (CBS). STUDY DESIGN AND METHODS: This simulation considered the following parameters: the risk of travel exposure in a high-risk ZIKV country, the duration of travel, the daily risk of acquiring ZIKV in a high-risk country, the probability of materno-fetal ZIKV transmission, the probability of asymptomatic fetal viremia, and the probability of sexual transmission. A hundred million Monte Carlo simulations were run. RESULTS: In the most-likely scenario (probability of traveling to a high-risk ZIKV country while pregnant = 0.178), the risk was estimated at 0.9 ZIKV-positive donations per million donations (95% confidence interval [CI] = 0.4-1.6)-or one every 868 years at HQ and one every 453 years at CBS. In the pessimistic model (probability of traveling to a high-risk ZIKV country while pregnant = 0.240), the risk was estimated at 1.2 ZIKV-positive donations per million donations (95% CI = 0.6-2.1)-or one every 644 years at HQ and one every 340 years at CBS. DISCUSSION: We conclude that the risk of introducing ZIKV in the Canadian CB supply is too small to justify maintaining the current policy.
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BACKGROUND: Hepatitis B core antibody (anti-HBc) screening has been implemented in many blood establishments to help prevent transmission of hepatitis B virus (HBV), including from donors with occult HBV infection (OBI). We review HBV screening algorithms across blood establishments globally and their potential effectiveness in reducing transmission risk. MATERIALS AND METHODS: A questionnaire on HBV screening and follow-up strategies was distributed to members of the International Society of Blood Transfusion working party on transfusion-transmitted infectious diseases. Screening data from 2022 were assimilated and analyzed. RESULTS: A total of 30 unique responses were received from 25 countries. Sixteen respondents screened all donations for anti-HBc, with 14 also screening all donations for HBV DNA. Anti-HBc prevalence was 0.42% in all blood donors and 1.19% in new donors in low-endemic countries; however, only 44% of respondents performed additional anti-HBc testing to exclude false reactivity. 0.68% of anti-HBc positive, HBsAg-negative donors had detectable HBV DNA. Ten respondents did universal HBV DNA screening without anti-HBc, whereas four respondents did not screen for either. Deferral strategies for anti-HBc positive donors were highly variable. One transfusion-transmission from an anti-HBc negative donor was reported. DISCUSSION: Anti-HBc screening identifies donors with OBI but also results in the unnecessary deferral of a significant number of donors with resolved HBV infection and donors with false-reactive anti-HBc results. Whilst confirmation of anti-HBc results could be improved to reduce donor deferral, transmission risks associated with anti-HBc negative OBI donors must be considered. In high-endemic areas, highly sensitive HBV DNA testing is required to identify infectious donors.
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BACKGROUND AND OBJECTIVES: In Canada, plasma sent for fractionation is tested for both parvovirus B19 (B19V) and hepatitis A virus (HAV). This study compared positivity rates of B19 and HAV nucleic acid tests (NATs) in Canadian plasma samples for the pre-COVID-19 restriction era (2015 to end of February 2020 [Q1] 2020) and the post-COVID-19 restriction era. MATERIALS AND METHODS: Pooled EDTA plasma specimens were tested within 24 months of blood draw using the Procleix Panther System (Grifols Diagnostic Solutions Inc, San Diego, CA, USA) for B19V and HAV detection. Reactive pools were resolved by individual specimen testing. RESULTS: Between 1 January 2015, and 31 March 2022, 3,928,619 specimens from Canadian plasma donors were tested for B19V. For the same period, 3,922,954 specimens were tested for HAV. To account for a lag in specimen testing for up to 24 months, the data were divided into: (1) a pre-pandemic period (1 January 2015-31 March 2020; B19V tested n = 2,412,701, B19V NAT-positive n = 240 [0.01%], HAV tested n = 2,407,036, HAV NAT-positive n = 26 [0.001%]); (2) a two-year mixed-impact period (1 April 2020-31 March 2022; B19V tested n = 968,250, B19V NAT-positive n = 14 [0.001%], HAV tested n = 968,250, HAV NAT-positive n = 2 [0.0002%]); and (3) a pandemic-impact period (1 April 2022-31 March, 2023; B19V tested n = 597,668, B19V NAT-positive n = 3 [0.0005%], HAV tested n = 597,668, HAV NAT-positive n = 1 [0.0002%]). CONCLUSION: The percentage of B19V- and HAV-positive donations was significantly reduced from the pre-pandemic period to the pandemic-impact period.
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Donantes de Sangre , COVID-19 , Parvovirus B19 Humano , Humanos , COVID-19/sangre , COVID-19/epidemiología , Canadá/epidemiología , Hepatitis A/sangre , Hepatitis A/epidemiología , SARS-CoV-2 , Masculino , Femenino , Virus de la Hepatitis A , Infecciones por Parvoviridae/sangre , Infecciones por Parvoviridae/epidemiologíaRESUMEN
BACKGROUND AND OBJECTIVES: There is a growing infectious syphilis outbreak in Western Canada. Although blood donors are screened for syphilis risks, some blood donors will still be confirmed test-positive for syphilis. This study compares the characteristics of confirmed test-positive syphilis donations in both Western Canada and Eastern Canada, November 2022-August 2023. MATERIALS AND METHODS: Donors were defined as Western or Eastern Canadian. Blood donations were tested for syphilis using the PK-TP assay (Beckman Coulter PK7300 Automated Microplate System). Confirmatory Treponema pallidum particle agglutination (TPPA) and rapid plasma reagin (RPR) assays were performed by one of two reference laboratories. An RPR titre ≥1:8 was used as a proxy for possible infectious syphilis. RESULTS: Rates of laboratory-confirmed syphilis were higher in Western (n = 43, 13.4/100,000 donations) versus Eastern donors (n = 19, 4.7/100,000 donations; Fisher's exact test, two-sided, p ≤ 0.0001). Most syphilis confirmations were in first-time donors (Western Canada n = 31/43, 72.1%, Eastern Canada 12/19, 63.2%). CONCLUSION: Although rates of laboratory-confirmed syphilis were higher in Western versus Eastern donors, Western donors did not have higher rates of infectious syphilis. Further studies might assess whether donors with laboratory-confirmed syphilis understood pre-donation screening questions or were completely unaware of a past infection.
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Donantes de Sangre , Sífilis , Humanos , Sífilis/epidemiología , Sífilis/sangre , Canadá/epidemiología , Masculino , Femenino , Adulto , Treponema pallidum , Persona de Mediana Edad , Serodiagnóstico de la Sífilis/métodosRESUMEN
BACKGROUND AND OBJECTIVES: Trypanosoma cruzi is the etiologic agent of Chagas disease (CD), an anthropozoonosis from the American continent that progresses from an acute phase to an indeterminate phase, followed by a chronic symptomatic phase in around 30% of patients. In countries where T. cruzi is not endemic, many blood transfusion services test blood donors who have stayed in an endemic country ('at-risk stay')-even if they do not present with other risk factors. However, the efficiency of this approach has been questioned. MATERIALS AND METHODS: On 18 September 2023, a worldwide survey was distributed among employees of blood transfusion services. The questions mainly pertained to CD's endemicity in the blood services' region, the current testing policy for T. cruzi and the number of confirmed positive results among donors with a prior at-risk stay alone (i.e., without other risk factors for T. cruzi infection). RESULTS: Twenty-six recipients completed the survey. Of the 22 (84.6%) blood services that operated in a non-endemic region, 9 (42.9%) tested donors for T. cruzi, including 8 (88.9%) that considered the travel history or the duration of the stay (alone) in their testing algorithm ('study blood services'). Over 93 years of observation among all study blood services, 2 donations from donors with an at-risk stay alone and 299 from those with other risk factors were confirmed positive for T. cruzi. CONCLUSION: The study findings question the utility of testing blood donors who have stayed in an endemic country without other risk factors.
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Donantes de Sangre , Enfermedad de Chagas , Enfermedades Endémicas , Trypanosoma cruzi , Humanos , Enfermedad de Chagas/epidemiología , Encuestas y Cuestionarios , Masculino , Selección de Donante/métodos , Femenino , Factores de Riesgo , ViajeRESUMEN
BACKGROUND AND OBJECTIVES: Hepatitis B virus (HBV) genotypes (A-H) have a distinct geographic distribution and are highly associated with the country of birth. Canada has experienced increased immigration over the past decade, primarily from regions where HBV is endemic. This study investigated the proportions and trends of HBV genotypes within blood donor and clinical populations of Canada over the period 2016-2021. MATERIALS AND METHODS: Study samples involved two cohorts: (1) Canadian blood donors (n = 246) deferred from donation due to HBV test positivity and (2) chronic HBV patients from across Canada (clinically referred population, n = 3539). Plasma or serum was extracted, and the surface antigen and/or polymerase-coding region was amplified and sequenced to determine genotype by phylogenetic analysis. RESULTS: Six (A-E, G) and eight (A-H) HBV genotypes were detected among deferred blood donors and the clinically referred population, respectively. Differences in HBV genotype proportions between the two cohorts were observed across Canada. Males comprised most of the referred population among genotypes A-E (p < 0.0001), except for genotypes B and C. The median age was younger among blood donors (36 years [range 17-72]) compared with the referred population (41 years [range 0-99]). Distinct trends of increasing (E, referred; B, blood donor) and decreasing genotype prevalence were observed over the study period. CONCLUSION: HBV genotypes in Canada are highly diverse, suggesting a large immigrant population. Observed trends in genotype prevalence and proportional differences among cohorts imply shifts among the HBV-infected population of Canada, which warrants continued surveillance.
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Virus de la Hepatitis B , Hepatitis B , Masculino , Humanos , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad , Anciano , Femenino , Virus de la Hepatitis B/genética , Donantes de Sangre , Hepatitis B/epidemiología , Filogenia , Canadá , Genotipo , Antígenos de Superficie de la Hepatitis B , ADN ViralRESUMEN
BACKGROUND AND OBJECTIVES: Data provided from blood donors have contributed to the understanding of public health epidemiology and policy decisions. A recent example was during the severe acute respiratory syndrome-related coronavirus (SARS-CoV-2) pandemic when blood services monitored the seroprevalence in blood donors. Based on this experience, blood services have the opportunity to expand their role and participate in public health surveillance and research. The aim of this report is to share available resources to assist blood services in this area. MATERIALS AND METHODS: The Surveillance, Risk Assessment and Policy (SRAP) Sub-group of the International Society of Blood Transfusion (ISBT) Transfusion Transmitted Infectious Diseases (TTID) Working Party developed a Public Health Research Toolkit to assist blood services and researchers interested in expanding their role in public health research. RESULTS: The ISBT Public Health Research Toolkit provides resources for what blood services can offer to public health, examples of donor research studies, the utility of donor data and website links to public health agencies. The toolkit includes a customizable template for those interested in establishing and managing a biobank. CONCLUSION: The ISBT Public Health Research Toolkit includes resources to increase the recognition of the role blood donors can play in public health and to help blood services gain commitment and funding from various agencies for new research and surveillance.
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Donantes de Sangre , Transfusión Sanguínea , COVID-19 , Salud Pública , Humanos , COVID-19/epidemiología , Medición de Riesgo , Transfusión Sanguínea/métodos , SARS-CoV-2 , Pandemias , Reacción a la Transfusión/epidemiología , Reacción a la Transfusión/prevención & control , Infecciones de Transmisión Sanguínea/prevención & control , Infecciones de Transmisión Sanguínea/epidemiologíaRESUMEN
BACKGROUND AND OBJECTIVES: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serosurveys are typically analysed by applying a fixed threshold for seropositivity ('conventional approach'). However, this approach underestimates the seroprevalence of anti-nucleocapsid (N) in vaccinated individuals-who often exhibit a difficult-to-detect anti-N response. This limitation is compounded by delays between the onset of infection and sample collection. To address this issue, we compared the performance of four immunoassays using a new analytical approach ('ratio-based approach'), which determines seropositivity based on an increase in anti-N levels. MATERIALS AND METHODS: Two groups of plasma donors and four immunoassays (Elecsys total anti-N, VITROS total anti-N, Architect anti-N Immunoglobulin G (IgG) and in-house total anti-N) were evaluated. First-group donors (N = 145) had one positive SARS-CoV-2 polymerase chain reaction (PCR) test result and had made two plasma donations, including one before and one after the PCR test (median = 27 days post-PCR). Second-group donors (N = 100) had made two plasma donations early in the Omicron wave. RESULTS: Among first-group donors (97.9% vaccinated), sensitivity estimates ranged from 60.0% to 89.0% with the conventional approach, compared with 94.5% to 98.6% with the ratio-based approach. Among second-group donors, Fleiss's κ ranged from 0.56 to 0.83 with the conventional approach, compared with 0.90 to 1.00 with the ratio-based approach. CONCLUSION: With the conventional approach, the sensitivity of four immunoassays-measured in a predominantly vaccinated population based on samples collected ~1 month after a positive test result-fell below regulatory agencies requirement of ≥95%. The ratio-based approach significantly improved the sensitivities and qualitative agreement among immunoassays, to the point where all would meet this requirement.
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Anticuerpos Antivirales , Vacunas contra la COVID-19 , COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/inmunología , COVID-19/prevención & control , COVID-19/sangre , COVID-19/inmunología , COVID-19/epidemiología , Inmunoensayo/métodos , Anticuerpos Antivirales/sangre , Vacunas contra la COVID-19/inmunología , Femenino , Masculino , Adulto , Prueba Serológica para COVID-19/métodos , Persona de Mediana Edad , Inmunoglobulina G/sangre , Estudios Seroepidemiológicos , Vacunación , Donantes de SangreRESUMEN
BACKGROUND AND OBJECTIVES: Until recently, gay, bisexual and other men who have sex with men (MSM) were deferred from donating blood for 3-12 months since the last male-to-male sexual contact. This MSM deferral has been discontinued by several high-income countries (HIC) that now perform gender-neutral donor selection. MATERIALS AND METHODS: An international symposium (held on 20-04-2023) gathered experts from seven HICs to (1) discuss how this paradigm shift might affect the mitigation strategies for transfusion-transmitted infections and (2) address the challenges related to gender-neutral donor selection. RESULTS: Most countries employed a similar approach for implementing a gender-neutral donor selection policy: key stakeholders were consulted; the transition was bridged by time-limited deferrals; donor compliance was monitored; and questions or remarks on anal sex and the number and/or type of sexual partners were often added. Many countries have now adopted a gender-neutral approach in which questions on pre- and post-exposure prophylaxis for human immunodeficiency virus (HIV) have been added (or retained, when already in place). Other countries used mitigation strategies, such as plasma quarantine or pathogen reduction technologies for plasma and/or platelets. CONCLUSION: The experience with gender-neutral donor selection has been largely positive among the countries covered herein and seems to be acceptable to stakeholders, donors and staff. The post-implementation surveillance data collected so far appear reassuring with regards to safety, although longer observation periods are necessary. The putative risks associated with HIV antiretrovirals should be further investigated.
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Infecciones por VIH , Minorías Sexuales y de Género , Humanos , Masculino , Femenino , Homosexualidad Masculina , Selección de Paciente , Infecciones por VIH/epidemiología , Donantes de Sangre , Conducta Sexual , Selección de DonanteRESUMEN
BACKGROUND AND OBJECTIVES: Nucleic acid-amplification testing (NAT) is used for screening blood donations/donors for blood-borne viruses. We reviewed global viral NAT characteristics and NAT-yield confirmatory testing used by blood operators. MATERIALS AND METHODS: NAT characteristics and NAT-yield confirmatory testing used during 2019 was surveyed internationally by the International Society of Blood Transfusion Working Party Transfusion-Transmitted Infectious Diseases. Reported characteristics are presented herein. RESULTS: NAT was mainly performed under government mandate. Human immunodeficiency virus (HIV), hepatitis C virus (HCV) and hepatitis B virus (HBV) NAT was performed on all donors and donation types, while selective testing was reported for West Nile virus, hepatitis E virus (HEV), and Zika virus. Individual donation NAT was used for HIV, HCV and HBV by ~50% of responders, while HEV was screened in mini-pools by 83% of responders performing HEV NAT. Confirmatory testing for NAT-yield samples was generally performed by NAT on a sample from the same donation or by NAT and serology on samples from the same donation and a follow-up sample. CONCLUSION: In the last decade, there has been a trend towards use of smaller pool sizes or individual donation NAT. We captured characteristics of NAT internationally in 2019 and provide insights into confirmatory testing approaches used for NAT-yields, potentially benefitting blood operators seeking to implement NAT.
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Donantes de Sangre , Técnicas de Amplificación de Ácido Nucleico , Humanos , Técnicas de Amplificación de Ácido Nucleico/métodos , Infecciones de Transmisión Sanguínea , Selección de Donante/métodosRESUMEN
BACKGROUND AND OBJECTIVES: Nucleic acid amplification testing (NAT), in blood services context, is used for the detection of viral and parasite nucleic acids to reduce transfusion-transmitted infections. This project reviewed NAT for screening blood donations globally. MATERIALS AND METHODS: A survey on NAT usage, developed by the International Society of Blood Transfusion Working Party on Transfusion-transmitted Infectious Diseases (ISBT WP-TTID), was distributed through ISBT WP-TTID members. Data were analysed using descriptive statistics. RESULTS: Forty-three responses were received from 32 countries. Increased adoption of blood donation viral screening by NAT was observed over the past decade. NAT-positive donations were detected for all viruses tested in 2019 (proportion of donations positive by NAT were 0.0099% for human immunodeficiency virus [HIV], 0.0063% for hepatitis C virus [HCV], 0.0247% for hepatitis B virus [HBV], 0.0323% for hepatitis E virus [HEV], 0.0014% for West Nile virus [WNV] and 0.00005% for Zika virus [ZIKV]). Globally, over 3100 NAT-positive donations were identified as NAT yield or solely by NAT in 2019 and over 22,000 since the introduction of NAT, with HBV accounting for over half. NAT-positivity rate was higher in first-time donors for all viruses tested except WNV. During 2019, a small number of participants performed NAT for parasites (Trypanosoma cruzi, Babesia spp., Plasmodium spp.). CONCLUSION: This survey captures current use of blood donation NAT globally. There has been increased NAT usage over the last decade. It is clear that NAT contributes to improving blood transfusion safety globally; however, there is a need to overcome economic barriers for regions/countries not performing NAT.
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Hepatitis B , Ácidos Nucleicos , Reacción a la Transfusión , Infección por el Virus Zika , Virus Zika , Humanos , Donación de Sangre , Donantes de Sangre , Hepatitis B/diagnóstico , Virus de la Hepatitis B/genética , Técnicas de Amplificación de Ácido NucleicoRESUMEN
BACKGROUND: The construct of "moral injury" is used widely in the research literature and media to broadly describe the impact of events involving perceived violations of one's sense of right and wrong (herein referred to as "potentially morally injurious events" [PMIEs]). SUMMARY: In this theoretical review, we provided a brief overview of the "moral injury" construct and its limitations including the lack of consensus-drawn boundaries and operational definitions to guide hypothesis-driven research. We discussed whether this construct can be reliably distinguished from established psychiatric diagnoses and psychological constructs and the inherent challenges in separating or classifying the impact of high-magnitude stressful life events that likely form the majority of PMIEs. Assessments that purportedly measure "moral injury" are reviewed and limitations are discussed such as shared measurement variance with established psychological instruments. KEY MESSAGES: We identified conceptual strategies for investigating behavioral and neurobiological features of PMIEs that could be used to inform the field of traumatic stress. We concluded that the construct of "moral injury" may provide an interpretive framework for positing why someone may be beset by guilt, shame, and/or rage whereas existing psychiatric diagnoses such as post-traumatic stress disorder and depression provide comprehensive descriptions regarding what someone might experience following extremely stressful events. We proposed directions to better clarify the boundaries of "moral injury" versus established psychiatric categories that could be used to enhance the conceptualization and assessment of this construct.
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BACKGROUND: Hepatitis C is a blood-borne infection with the hepatitis C virus (HCV) that can progress to cirrhosis and liver cancer. About 70% (50-80%) of infections become chronic and exhibit anti-HCV and HCV nucleic acid (NAT) positivity. Direct acting oral pan genotypic antiviral treatment became available in 2014 and was free for most Canadians in 2018. Clinical screening for HCV infection is risk-based. About 1% of Canadians have been infected with HCV, with 0.5% chronically infected (about 25% unaware) disproportionately impacting marginalized groups. Blood donors are in good health, are deferred for risks such as injection drug use and can provide insight into the low-risk undiagnosed population. Here we describe HCV epidemiology in first-time blood donors over 28 years of monitoring. METHODS: All first-time blood donors in all Canadian provinces except Quebec (1993 to 2021) were analyzed. All blood donations were tested for HCV antibodies (anti-HCV) and since late 1999 also HCV NAT. A case-control study was also included. All HCV positive donors (cases) since 2005 and HCV negative donors (1:4 ratio controls) matched for age, sex and location were invited to complete a risk factor interview. Separate logistic regression models for anti-HCV positivity and chronic HCV assessed the association between age cohort, sex, region and neighbourhood material deprivation and ethnocultural concentration. CASE: control data were analysed by logistic regression. RESULTS: There were 2,334,238 donors from 1993 to 2021 included. Prevalence for anti-HCV was 0.33% (0.30,0.37) in 1993 and 0.07% (0.05,0.09) in 2021 (p < 0.0001). In 2021 0.03% (0.01,0.04) had chronic HCV. Predictors for both anti-HCV positivity and chronic HCV were similar, for chronic HCV were male sex (OR 1.8, 1.6,2.1), birth between 1945 and 1975 (OR 7.1, 5.9,8.5), living in the western provinces (OR 1.4, 1.2,1.7) and living in material deprived (OR 2.7, 2.1,3.5) and more ethnocultural concentrated neighbourhoods (OR 1.8, 1.3,2.5). There were 318 (35.4%) of chronic HCV positive and 1272 (39.6%) of controls who participated in case control interviews. The strongest risks for acquisition were injection drug use (OR 96.9, 22.3,420.3) and birth in a high prevalence country (OR 24.5, 11.2,53.6). CONCLUSIONS: Blood donors have 16 times lower HCV prevalence then the general population. Donors largely mirror population trends and highlight the ongoing prevalence of untreated infections in groups without obvious risks for acquisition missed by risk-based patient screening.
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Donantes de Sangre , Hepatitis C , Humanos , Donantes de Sangre/estadística & datos numéricos , Masculino , Femenino , Canadá/epidemiología , Adulto , Hepatitis C/epidemiología , Hepatitis C/diagnóstico , Persona de Mediana Edad , Estudios de Casos y Controles , Adulto Joven , Factores de Riesgo , Hepacivirus/aislamiento & purificación , Prevalencia , AdolescenteRESUMEN
Babesia spp. are tick-borne parasites with a global distribution and diversity of vertebrate hosts. Over the next several decades, climate change is expected to impact humans, vectors, and vertebrate hosts and change the epidemiology of Babesia. Although humans are dead-end hosts for tick-transmitted Babesia, human-to-human transmission of Babesia spp. from transfusion of red blood cells and whole blood-derived platelet concentrates has been reported. In most patients, transfusion-transmitted Babesia (TTB) results in a moderate-to-severe illness. Currently, in North America, most cases of TTB have been described in the United States. TTB cases outside North America are rare, but case numbers may change over time with increased recognition of babesiosis and as the epidemiology of Babesia is impacted by climate change. Therefore, TTB is a concern of microbiologists working in blood operator settings, as well as in clinical settings where transfusion occurs. Microbiologists play an important role in deploying blood donor screening assays in Babesia endemic regions, identifying changing risks for Babesia in non-endemic areas, investigating recipients of blood products for TTB, and drafting TTB policies and guidelines. In this review, we provide an overview of the clinical presentation and epidemiology of TTB. We identify approaches and technologies to reduce the risk of collecting blood products from Babesia-infected donors and describe how investigations of TTB are undertaken. We also describe how microbiologists in Babesia non-endemic regions can assess for changing risks of TTB and decide when to focus on laboratory-test-based approaches or pathogen reduction to reduce TTB risk.
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Babesia microti , Babesia , Babesiosis , Humanos , Estados Unidos , Transfusión Sanguínea , Babesiosis/epidemiología , Donantes de SangreRESUMEN
BACKGROUND: In Canada the time deferral for gay, bisexual, and other men who have sex with men (gbMSM) was progressively shortened (lifetime, 5 years, 1 year, 3 months). Here we describe trends in syphilis rates (a potential sexual risk marker) and risk behaviors from blood donors in the past 12 years. STUDY DESIGN AND METHODS: Syphilis positivity in 10,288,322 whole blood donations (January 1, 2010-September 10, 2022) and gbMSM deferral time periods, donation status, age, and sex were analyzed with logistic regression. Overall, 26.9% syphilis positive and 42.2% controls (matched 1:4) participated in risk factor interviews analyzed by logistic regression. RESULTS: Syphilis rates were higher in first-time donors (OR 27.0, 95% CI 22.1-33.0), in males (OR 2.3, 1.9-2.8) and with the 3-month deferral (OR 3.4, 2.6-4.3) during which the increase was greater for first-time males (p < .001) but similar for male and female repeat donors (p > .05). Among first-time donors, histories of intravenous drug use (OR 11.7, 2.0-69.5), male-to-male sex 7.8 (2.0-30.2) and birth in a high prevalence country (OR 7.6, 4.4-13.0) predicted syphilis positivity; among repeat donors, history of male-to-male sex (OR 33.5, CI 3.5-317.0). All but 1 gbMSM syphilis-positive donors were noncompliant with the gbMSM deferral. About a quarter of first-time interviewed case donors had history of syphilis; 44% were born in a high-prevalence country. CONCLUSION: Rising syphilis rates in donors correlates with the general population epidemic. Recent infection rates rose similarly in males and females. GbMSM history may contribute to donor syphilis rates but shortening time deferrals appears unrelated.
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Infecciones por VIH , Minorías Sexuales y de Género , Sífilis , Humanos , Masculino , Femenino , Sífilis/epidemiología , Homosexualidad Masculina , Donantes de Sangre , BiomarcadoresRESUMEN
BACKGROUND: In 2021, Canada implemented a pilot plasma program allowing some sexually active men who have sex with men (including but not limited to gay and bisexual men; gbMSM) to donate plasma. Changes to plasma donation policy could help address inequities in access to plasma donation and increase Canada's domestically collected plasma supply if more gbMSM donate as a result. We aimed to (1) examine views regarding plasma donation and the pilot program prior to implementation and (2) identify modifiable theory-informed predictors of gbMSM's intention to donate plasma. METHODS: We developed, piloted, and disseminated a questionnaire informed by the Theoretical Domains Framework (TDF). We recruited gbMSM in London (ON) and Calgary (AB) to an anonymous, online cross-sectional survey. RESULTS: A total of 246 gbMSM completed the survey. On scales from 1 (strongly disagree) to 5 (strongly agree), general intention to donate was high (mean = 4.24; SD = 0.94). The pilot program itself was mostly acceptable (mean = 3.71, SD = 1.16), but the intention to donate under the unique requirements of the pilot program was lower than general intention (mean = 3.58; SD = 1.26). Two domains from the theoretical domains framework (TDF) (beliefs about consequences of donating plasma and social influences) were independently associated with general intention to donate. DISCUSSION: The pilot plasma program as an incremental step toward more inclusive policies was mostly viewed as acceptable by the impacted communities. Historical and ongoing exclusions create unique barriers to donation. There are clear opportunities for developing theory-informed interventions to support gbMSM to donate plasma as policies continue to become more inclusive and more become eligible to donate.
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Homosexualidad Masculina , Minorías Sexuales y de Género , Masculino , Humanos , Donación de Sangre , Estudios Transversales , Encuestas y Cuestionarios , PolíticasRESUMEN
BACKGROUND AND OBJECTIVES: Policies regarding medication use vary between blood centres. We evaluated medication use in eligible Canadian Blood Services whole blood donors to inform possible process improvements and allow comparisons between donors and the general population. MATERIALS AND METHODS: All donors are asked about medication use in the last 3 days, and medications and their reason for use are documented in our donor computer system. Donor computer records were reviewed from January 1, 2020, to March 31, 2022 to extract information on medications by donor age and sex; medications were grouped into therapeutic classes. Stability of medication use over time was determined in a random sample of 100 donors who made at least two donations in the study period. RESULTS: One-third of successful (eligible) donors were taking medications; of these, 80% were on one or two medications. Five classes of medication accounted for 72% of medication use, and 13 classes account for 93% of use. Use remains relatively stable over time. CONCLUSION: Medication use is common, with a few classes accounting for most use. Drop-down lists and storage of information from one donation to the next may enhance efficiency.
Asunto(s)
Donantes de Sangre , Humanos , CanadáRESUMEN
BACKGROUND AND OBJECTIVES: The distribution of rare and specific red cell phenotypes varies between races and ethnicities. Therefore, the most compatible red cell units for patients with haemoglobinopathies and other rare blood requirements are most likely to be found in donors from similar genetic backgrounds. Our blood service introduced a voluntary question asking donors to provide their racial background/ethnicity. Results triggered additional phenotyping and/or genotyping. MATERIALS AND METHODS: We analysed the results of additional testing performed between January 2021 and June 2022, and rare donors were added to the Rare Blood Donor database. We determined the incidence of various rare phenotypes and blood group alleles based on donor race/ethnicity. RESULTS: Over 95% of donors answered the voluntary question; 715 samples were tested, and 25 donors were added to the Rare Blood Donor database, including five k-, four U-, two Jk(a-b-) and two D- - phenotypes. CONCLUSION: Asking donors about their race/ethnicity was well received by donors, and the resulting selective testing enabled us to identify individuals with a higher likelihood of being rare blood donors, support patients with rare blood requirements and better understand the incidence of common and rare alleles and red blood cell phenotypes in the Canadian donor population.