Publications by authors named "Sheila O'Brien"
Background And Objectives: Despite screening procedures, a few blood donors confirm positive for transfusion-transmissible infections and are deferred. Effective notification of laboratory results is essential to ensure that donors are advised of confirmed results and to seek medical care. Here we report results from post-notification interviews of Canadian Blood Services donors.
View Article and Find Full Text PDFWest Nile virus (WNV) is a mosquito-borne zoonotic flavivirus which often causes asymptomatic infection in humans but may develop into a deadly neuroinvasive disease. In this study, we aimed to investigate variables potentially associated with human WNV infection using human and mosquito WNV surveillance and monitoring datasets, established over 20 years, from 2003 to 2022, across the province of Ontario, Canada. We combined climatic and geographic data, mosquito surveillance data (n = 3010 sites), blood donation arboviral detection testing data in the human population, and demographic and socio-economic data from Canadian population censuses.
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- Canadian Blood Services changed their deferral policy for HIV prevention treatments (PrEP/PEP) from a time-based approach to focusing on sexual risk behaviors, causing changes in donor deferrals.
- Data analysis over 22 months showed a stable rate of PEP deferrals while PrEP deferrals significantly increased from 5.9 to 12.4 per 100,000 donations. Many donors deferred were younger males or first-time users.
- The conclusion indicates that the new criteria slightly raised PrEP deferrals, but the full impact might not be captured as potential donors could be self-deferring due to increased awareness and usage of PrEP.
Objective: Military experiences that violate one's sense of right and wrong (i.e., potentially morally injurious events [PMIEs]) may result in moral injury, characterized by shame, guilt, demoralization, self-condemnation, and social withdrawal.
View Article and Find Full Text PDFBackground: 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).
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- Hepatitis B core antibody (anti-HBc) screening is used in blood establishments worldwide to help prevent the transmission of hepatitis B virus (HBV), especially from donors with occult HBV infection (OBI).
- A survey conducted revealed varied practices in HBV screening across 30 responses from 25 countries, with some establishments screening all donations for anti-HBc and HBV DNA, while others had different approaches, leading to inconsistencies in donor deferral strategies.
- The findings highlight the need for improved confirmation of anti-HBc results to minimize unnecessary donor deferrals while balancing the risk of transmission from anti-HBc negative OBI donors, particularly in high-endemic regions where sensitive HBV DNA testing is crucial.
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.
View Article and Find Full Text PDFBackground: 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.
Article Synopsis
- Blood donations have played a critical role in advancing public health understanding, especially highlighted during the SARS-CoV-2 pandemic, which showed the potential for blood services to contribute to public health surveillance and research.
- The International Society of Blood Transfusion (ISBT) created a Public Health Research Toolkit to support blood services and researchers in expanding their involvement in public health initiatives.
- This toolkit offers resources and templates for blood services to leverage donor data, engage in research studies, and establish biobanks, ultimately aiming to enhance recognition and funding for public health contributions.
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.
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- In Canada, each province and territory handles their own health data, which made it tricky to share information during the COVID-19 pandemic.
- There were 11 different surveys done to test how many people had antibodies from the virus, but they each used different methods, making it hard to compare results across regions.
- To do better in the future, Canada needs a strong and flexible system for tracking health data that can quickly adjust to new situations and work together across different areas.
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.
View Article and Find Full Text PDFBackground: In Canada's largest COVID-19 serological study, SARS-CoV-2 antibodies in blood donors have been monitored since 2020. No study has analysed changes in the association between anti-N seropositivity (a marker of recent infection) and geographic and sociodemographic characteristics over the pandemic.
Methods: Using Bayesian multi-level models with spatial effects at the census division level, we analysed changes in correlates of SARS-CoV-2 anti-N seropositivity across three periods in which different variants predominated (pre-Delta, Delta and Omicron).
Article Synopsis
- Canadian blood donors played a critical role in tracking anti-SARS-CoV-2 antibodies during the pandemic, allowing researchers to compare vaccination rates between donors and the general population.
- A study involving 165,240 blood donors in Canada showed that while the general population initially vaccinated at a higher rate, by mid-2021, blood donors had a higher percentage of vaccination antibodies.
- Survey results indicated that a significant portion of blood donors believed in the importance of vaccination, with 83.5% recognizing the seriousness of COVID-19 and 77.8% believing even those previously infected should get vaccinated.
Article Synopsis
- - The Canadian blood suppliers, Canadian Blood Services and Héma-Québec, shifted from a time-based deferral for men who have sex with men to a risk-based assessment focusing on sexual behaviors starting in 2022.
- - A study assessed the impact of these changes by monitoring HIV rates before and after implementation and found no significant difference in HIV-positive donations (0.27/100,000 pre-implementation vs. 0.28/100,000 post).
- - The deferral rate for donors due to new or multiple sexual partners was low (0.17%) and primarily affected first-time and younger donors, indicating the new screening process maintained safety while allowing more inclusive donor participation.
Article Synopsis
- The study aimed to estimate the prevalence of HTLV-1/2 viruses in Canadian blood donors and identify demographic risk factors associated with infection from 1990 to 2022.
- Analysis involved testing blood samples from first-time donors across Canada (except Quebec) and conducting risk factor interviews with identified cases and matched controls.
- Results showed a low prevalence of HTLV-1/2 (12 per 100,000), higher odds in females, older age groups, and those from certain regions, while highlighting that infection likely occurs both overseas and within Canada.
Background And Objectives: The process of selecting blood donors is crucial for keeping the health of donors and ensuring the safety of the blood supply. However, it may create unpleasant feeling in those who are deferred. In this study, we aim to explore the return rates of Iranian deferred donors in comparison with eligible donors.
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- Traditional methods for analyzing SARS-CoV-2 seroprevalence often underestimate antibody presence in vaccinated individuals, particularly in detecting anti-nucleocapsid responses.
- A study compared four different immunoassays using a new method that focuses on increases in anti-N antibody levels, revealing significantly better sensitivity than conventional approaches.
- Results showed that while the conventional approach fell short of regulatory standards for sensitivity, the new ratio-based method allowed all tested immunoassays to meet the necessary criteria, enhancing reliability in assessing seroprevalence.
SARS-CoV-2 seroprevalence in Nova Scotia blood donors.
J Assoc Med Microbiol Infect Dis Can
March 2024
Background: SARS-CoV-2 seroprevalence monitors cumulative infection rates irrespective of case testing protocols. We aimed to describe Nova Scotia blood donor seroprevalence in relation to public health policy and reported data over the course of the COVID-19 pandemic (May 2020 to August 2022).
Methods: Monthly random Nova Scotia blood donation samples (24,258 in total) were tested for SARS-CoV-2 infection antibodies (anti-nucleocapsid) from May 2020 to August 2022, and vaccination antibodies (anti-spike) from January 2021 to August 2022.
Article Synopsis
- Nucleic acid-amplification testing (NAT) is a method used to check blood donations for harmful viruses to keep people safe.
- In 2019, a global survey showed that countries mostly followed government rules for testing blood for viruses like HIV and hepatitis.
- The results indicated a trend towards using individual samples for testing instead of larger pools to improve safety in blood donations.
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.
Article Synopsis
- The project reviewed the global use of nucleic acid amplification testing (NAT) in blood services to detect viral and parasite nucleic acids and reduce transfusion-related infections.
- A survey conducted among members of the International Society of Blood Transfusion revealed a significant increase in NAT adoption over the past decade, with data showing low but notable positivity rates for various viruses in blood donations.
- While NAT has enhanced blood transfusion safety worldwide, there is a call to address economic barriers that prevent some regions from implementing these important testing methods.
Article Synopsis
- Several high-income countries have ended the practice of deferring gay, bisexual, and other men who have sex with men (MSM) from donating blood, moving towards a gender-neutral donor selection approach.
- An international symposium held in April 2023 brought together experts to discuss the impacts of this shift on transfusion safety and the challenges of implementing such policies.
- Findings indicate that most countries adopted similar strategies for this transition, which were positively received by stakeholders and showed reassuring safety data, although further research on HIV risks is needed.
Article Synopsis
- Hepatitis B is transmitted through sexual contact, blood exposure, and from mother to child, with higher chronic infection rates found in immigrants and their Canadian-born children.
- A study analyzing data from over 1.5 million Canadian blood donors identified a chronic hepatitis B prevalence of 47.5 cases per 100,000, particularly among males, older individuals, and those from lower-income and ethnically diverse neighborhoods.
- The research underscores the need for better diagnosis and treatment of chronic hepatitis B, especially in low-risk populations who may not be aware of their infection status.
Article Synopsis
- This study examined the distribution and trends of Hepatitis B virus (HBV) genotypes in Canada from 2016 to 2021, focusing on blood donors and chronic HBV patients due to increased immigration from endemic regions.
- Six HBV genotypes were found in blood donors, while eight were identified in chronic patients, with significant demographic differences, particularly concerning gender and age.
- The findings indicate a diverse HBV population in Canada and suggest that ongoing monitoring is necessary due to changes in genotype prevalence among the affected groups.