33 research outputs found
Factors associated with knowledge and awareness of Hepatitis B in individuals of Chinese descent:Results from a mass point of care testing and outreach campaign in Toronto, Canada
BACKGROUND: Migrants from hepatitis B virus (HBV) endemic regions are at high risk of having chronic infection. Despite this, HBV knowledge and awareness programming, and low-barrier screening methods such as point of care (POC) testing, among this group have yet to become routine. METHODS: We conducted a mass HBV POC screening and knowledge and awareness campaign for individuals of Chinese descent in Toronto, Canada. POC screening was administered, then participants completed a knowledge questionnaire. Logistic regression identified associations between demographic factors and participants’ level of HBV knowledge. RESULTS: From 2015 to 2018, 33 outreach events resulted in 891 individuals completing testing and the knowledge questionnaire. Individuals averaged 64.4 years old. Most, 62% (N = 552), were female, and 73.6% (N = 656) have been in Canada for <30 years. The average questionnaire score was 70.7% correct, with 65.2% (N = 581) demonstrating a high level of HBV knowledge. Post-secondary education (OR: 2.19, 95% CI: 1.41, 3.39), income of 50,000 to <75,000 (OR: 2.74, 95% CI: 1.39, 5.43), and having familial history of HBV (OR: 1.72, 95% CI: 1.06, 2.78) were associated with high knowledge. The observed prevalence of HBV was 1.5%, with 13 individuals testing positive on the POC test and confirmatory laboratory testing. CONCLUSIONS: Improving knowledge and awareness of HBV is critical to empowering people, especially migrants who experience barriers to care, to pursue vaccination, testing, and treatment. Combining knowledge outreach and POC test campaigns, enabled discussion and screening for HBV with large numbers of people, and can be tailored for optimal effectiveness for specific groups.</p
Factors associated with knowledge and awareness of Hepatitis B in individuals of Chinese descent:Results from a mass point of care testing and outreach campaign in Toronto, Canada
BACKGROUND: Migrants from hepatitis B virus (HBV) endemic regions are at high risk of having chronic infection. Despite this, HBV knowledge and awareness programming, and low-barrier screening methods such as point of care (POC) testing, among this group have yet to become routine. METHODS: We conducted a mass HBV POC screening and knowledge and awareness campaign for individuals of Chinese descent in Toronto, Canada. POC screening was administered, then participants completed a knowledge questionnaire. Logistic regression identified associations between demographic factors and participants’ level of HBV knowledge. RESULTS: From 2015 to 2018, 33 outreach events resulted in 891 individuals completing testing and the knowledge questionnaire. Individuals averaged 64.4 years old. Most, 62% (N = 552), were female, and 73.6% (N = 656) have been in Canada for <30 years. The average questionnaire score was 70.7% correct, with 65.2% (N = 581) demonstrating a high level of HBV knowledge. Post-secondary education (OR: 2.19, 95% CI: 1.41, 3.39), income of 50,000 to <75,000 (OR: 2.74, 95% CI: 1.39, 5.43), and having familial history of HBV (OR: 1.72, 95% CI: 1.06, 2.78) were associated with high knowledge. The observed prevalence of HBV was 1.5%, with 13 individuals testing positive on the POC test and confirmatory laboratory testing. CONCLUSIONS: Improving knowledge and awareness of HBV is critical to empowering people, especially migrants who experience barriers to care, to pursue vaccination, testing, and treatment. Combining knowledge outreach and POC test campaigns, enabled discussion and screening for HBV with large numbers of people, and can be tailored for optimal effectiveness for specific groups.</p
Hepatitis D double reflex testing of all hepatitis B carriers in low-HBV- and high-HBV/HDV-prevalence countries
Hepatitis D virus (HDV) infection occurs as a coinfection with hepatitis B and increases the risk of hepatocellular carcinoma, decompensated cirrhosis, and mortality compared to hepatitis B virus (HBV) monoinfection. Reliable estimates of the prevalence of HDV infection and disease burden are essential to formulate strategies to find coinfected individuals more effectively and efficiently. The global prevalence of HBV infections was estimated to be 262,240,000 in 2021. Only 1,994,000 of the HBV infections were newly diagnosed in 2021, with more than half of the new diagnoses made in China. Our initial estimates indicated a much lower prevalence of HDV antibody (anti-HDV) and HDV RNA positivity than previously reported in published studies. Accurate estimates of HDV prevalence are needed. The most effective method to generate estimates of the prevalence of anti-HDV and HDV RNA positivity and to find undiagnosed individuals at the national level is to implement double reflex testing. This requires anti-HDV testing of all hepatitis B surface antigen-positive individuals and HDV RNA testing of all anti-HDV-positive individuals. This strategy is manageable for healthcare systems since the number of newly diagnosed HBV cases is low. At the global level, a comprehensive HDV screening strategy would require only 1,994,000 HDV antibody tests and less than 89,000 HDV PCR tests. Double reflex testing is the preferred strategy in countries with a low prevalence of HBV and those with a high prevalence of both HBV and HDV. For example, in the European Union and North America only 35,000 and 22,000 cases, respectively, will require anti-HDV testing annually
From the notorious to the novel: identifying and characterizing mutations in HIV-1 reverse transcriptase and integrase
34 million individuals worldwide are currently infected with the human immunodeficiency virus (HIV). Following the isolation of HIV, the first direct acting antiviral was approved. This particular compound targeted the reverse transcriptase (RT) enzyme, and resulted in a decrease in viral load in patients receiving therapy. Shortly after, it was demonstrated that the use of a single inhibitor quickly leads to the selection of drug resistance mutations, and subsequently to viral rebound. To combat this, combination therapy was introduced which targets multiple proteins, including RT and other enzymes, such as HIV integrase (IN). RT reverse transcribes the single-stranded RNA genome into double-stranded DNA, followed by the insertion of this product into the host genome by IN. A detailed understanding of the mechanism of action of the drug target, the inhibitor itself, as well as how resistance-associated mutations act, is necessary to improve current therapies. Typically, drug resistance mutations occur near the binding site of the inhibitor. However, the first part of this thesis examines a mutation in HIV-1 RT, N348I, which confers, and is distant from the binding site of, both nucleoside reverse transcriptase inhibitors, and non-nucleoside reverse transcriptase inhibitors (NNRTIs). We describe the specific stage during HIV-1 reverse transcription where N348I exerts its effect on the first-generation NNRTI, neverapine, but not efavirenz. RT is targeted by multiple classes of drugs, while only one inhibitor, raltegravir (RAL), is currently approved to target HIV-1 IN. The development of IN inhibitors has been hindered by the lack of structural information with respect to the enzyme, IN-DNA interactions, as well as the mechanism of action of RAL. We pinpoint several interactions between HIV-1 IN and its DNA substrate, which are important for enzymatic activity. We also elucidate the contributions of these interactions in the context of inhibition by RAL, with respect to the wild-type enzyme, as well as the IN drug resistance mutation N155H. Following the acquisition of primary resistance mutations in HIV-1 IN, such as N155H, secondary mutations often appear. These mutations compensate for decreased viral fitness, and can potentially amplify resistance. The final study presented herein, examines whether one such mutation recently identified in RAL-experienced patients at position N117, confers resistance to RAL.34 millions de personnes dans le monde sont infectées par le virus de l'immunodéficience humaine (VIH). Après l'isolement du VIH, le premier antiviral d'action directe a été approuvé. Cet antirétroviral ciblait l'enzyme de la transcriptase inverse (RT), et entrainait une diminution de la réplication virale chez les patients. Peu de temps après, il a été démontré que l'utilisation d'un seul inhibiteur conduit rapidement à la sélection de mutations de résistance contre le médicament, et par conséquent un rebond de la réplication virale. Pour résoudre ce problème, la thérapie combinée a été introduite. Celle-ci repose sur le principe où plusieurs protéines virales sont ciblé simultanément comme par exemple RT et l'intégrase du VIH (IN). RT permet de transcrire en direction inverse (rétrotranscription) l'ARN génomiques virale en ADN, suivie par l'insertion de cet ADN dans l'ADN génomique de l'hôte par IN. Une compréhension du mécanisme d'action de la cible du médicament, de l'inhibiteur lui-même, ainsi que du mécansime conférant les mutations de résistance aux inhibiteurs viraux est nécessaire pour améliorer les traitements courants. En règle générale, les mutations qui confèrent une résistance aux médicaments ce produisent a proximité du site de liaison de l'inhibiteur. Toutefois, la première partie de cette thèse examine une mutation du VIH-1 RT, N348I, qui confère la résistance malgré le fait que la mutation soit éloigné du site de liaison des inhibiteurs nucléosidique (NRTIs) et non nucléosidique de la transcriptase inverse (NNRTIs). Notre étude nous permet de décrire l'étape spécifique lors de la transcription inverse du VIH-1 où N348I exerce son effet sur un NNRTI de première génération, la névirapine, mais pas sur l'éfavirenz. Alors qu'une multitude de médicaments appartenant soit aux NRTIs ou aux NNRTIs cible la RT, un seul inhibiteur, le raltégravir (RAL), est actuellement approuvé pour cibler l'IN du VIH-1. Le développement d'inhibiteurs de l'IN a été entravée par le manque d'information structurelle à l'égard de l'enzyme, les interactions entre l'IN et l'ADN, ainsi que le mécanisme d'action du RAL. Notre étude a permis de characteriser plusieurs interactions entre le VIH-1 IN et son substrat d'ADN qui sont importantes pour l'activité enzymatique. Également, nous avons élucidé les contributions de ces interactions dans le contexte de l'inhibition par le RAL à l'égard de l'enzyme de type sauvage, ainsi qu'en présence de la mutation de résistance au médicament N155H . Suite à l'acquisition de mutations de résistance primaires du VIH-1 IN, tels que N155H, des mutations secondaires apparaissent souvent. Ces mutations compensent pour la diminution de l'efficacité virale tout en amplifiant significativement la résistance au médicament. Finalement, la dernière étude présentée ici examine si une telle mutation qui a été récemment identifié en position N117 chez les patients traités avec le RAL confère une résistance au médicament
Hepatitis B and C in Pregnancy and Children: A Canadian Perspective
In 2016, the World Health Organization released a plan to eliminate viral hepatitis as a public health threat by 2030. For Canada to achieve the recommended decreases in HBV- and HCV-related new diagnoses and deaths, an increase in services is urgently required. Identifying those at risk of, or who have acquired HBV and HCV, remains a challenge, especially with the emergence of new priority populations such as pregnant persons and children. Importantly, prenatal, and pediatric care are times when individuals are often already engaged with the healthcare system, leading to the potential for opportunistic or co-localized care and interventions. At present, Canada may not be maximizing all available virologic tools that could lead to increases in prevention, identification, improved management, or even cure. Here, we describe the continuum of care that includes preconception, prenatal, postpartum, and pediatric stages; and identify current global and Canadian recommendations, findings, and opportunities for improvement
Recognition of Long-COVID-19 Patients in a Canadian Tertiary Hospital Setting: A Retrospective Analysis of Their Clinical and Laboratory Characteristics
A proportion of patients with COVID-19 have symptoms past the acute disease phase, which may affect quality of life. It is important for clinicians to be aware of this “long-COVID-19” syndrome to better diagnose, treat, and prevent it. We reviewed clinical and laboratory characteristics of a COVID-19 cohort in a Toronto, Ontario tertiary care center. Demographic, clinical, and laboratory data were collected, and patients were classified as “long-COVID-19” or “non-long-COVID-19” using consensus criteria. Of 397 patients who tested positive for COVID-19, 223 met inclusion criteria, and 62 (27%) had long-COVID-19. These patients had a similar age distribution compared to non-long-COVID-19 patients overall but were younger in the admitted long COVID-19 group. The long-COVID-19 group had more inpatients compared to the non-long-COVID-19 group (39% vs. 25%) and more frequent supplemental oxygen or mechanical ventilation use. However, long-COVID-19 patients did not differ by duration of mechanical ventilation, length of stay, comorbidities, or values of common laboratory tests ordered. The most frequent symptoms associated with long-COVID-19 were fatigue and weakness, as reported most commonly by the infectious disease, respirology and cardiology disciplines. In conclusion, by retrospective chart review, 27% of COVID-19 patients presenting to a tertiary care center in Toronto, Canada, were found to meet criteria for long-COVID-19. Past medical history and routine laboratory testing at presentation did not predict for long-COVID-19 development
Clinical Validation of Quantum Dot Barcode Diagnostic Technology
There
has been a major focus on the clinical translation of emerging
technologies for diagnosing patients with infectious diseases, cancer,
heart disease, and diabetes. However, most developments still remain
at the academic stage where researchers use spiked target molecules
to demonstrate the utility of a technology and assess the analytical
performance. This approach does not account for the biological complexities
and variabilities of human patient samples. As a technology matures
and potentially becomes clinically viable, one important intermediate
step in the translation process is to conduct a full clinical validation
of the technology using a large number of patient samples. Here, we
present a full detailed clinical validation of Quantum Dot (QD) barcode
technology for diagnosing patients infected with Hepatitis B Virus
(HBV). We further demonstrate that the detection of multiple regions
of the viral genome using multiplexed QD barcodes improved clinical
sensitivity from 54.9–66.7% to 80.4–90.5%, and describe
how to use QD barcodes for optimal clinical diagnosis of patients.
The use of QDs in biology and medicine was first introduced in 1998
but has not reached clinical care. This study describes our long-term
systematic development strategy to advance QD technology to a clinically
feasible product for diagnosing patients. Our “blueprint”
for translating the QD barcode research concept could be adapted for
other nanotechnologies, to efficiently advance diagnostic techniques
discovered in the academic laboratory to patient care
Best practices for hepatitis C linkage to care in pregnant and postpartum women: Perspectives from the TiP-HepC Community of Practice
There is an increasing burden of hepatitis C virus (HCV) among persons of reproductive age, including pregnant and breastfeeding women, in many regions worldwide. Routine health services during pregnancy present a critical window of opportunity to diagnose and link women with HCV infection for care and treatment to decrease HCV-related morbidity and early mortality. Effective treatment of HCV infection in women diagnosed during pregnancy also prevents HCV-related adverse events in pregnancy and HCV vertical transmission in future pregnancies. However, linkage to care and treatment for women diagnosed in pregnancy remains insufficient. Currently, there are no best practice recommendations from professional societies to ensure appropriate peripartum linkage to HCV care and treatment. We convened a virtual Community of Practice (CoP) to understand key challenges to the HCV care cascade for women diagnosed with HCV in pregnancy, highlight published models of integrated HCV services for pregnant and postpartum women, and preview upcoming research and programmatic initiatives to improve linkage to HCV care for this population. Four-hundred seventy-three participants from 43 countries participated in the CoP, including a diverse range of practitioners from public health, primary care, and clinical specialties. The CoP included panel sessions with representatives from major professional societies in obstetrics/gynecology, maternal fetal medicine, addiction medicine, hepatology, and infectious diseases. From this CoP, we provide a series of best practices to improve linkage to HCV treatment for pregnant and postpartum women, including specific interventions to enhance co-location of services, treatment by non-specialist providers, active engagement and patient navigation, and decreasing time to HCV treatment initiation. The CoP aims to further support antenatal providers in improving linkage to care by producing and disseminating detailed operational guidance and recommendations and supporting operational research on models for linkage and treatment. Additionally, the CoP may be leveraged to build training materials and toolkits for antenatal providers, convene experts to formalize operational recommendations, and conduct surveys to understand needs of antenatal providers. Such actions are required to ensure equitable access to HCV treatment for women diagnosed with HCV in pregnancy and urgently needed to achieve the ambitious targets for HCV elimination by 2030
Evaluation of Dried Blood Spot Testing for SARS-CoV-2 Serology Using a Quantitative Commercial Assay
Dried blood spots (DBS) are commonly used for serologic testing for viruses and provide an alternative collection method when phlebotomy and/or conventional laboratory testing are not readily available. DBS collection could be used to facilitate widespread testing for SARS-CoV-2 antibodies to document past infection, vaccination, and potentially immunity. We investigated the characteristics of Roche’s Anti-SARS-CoV-2 (S) assay, a quantitative commercial assay for antibodies against the spike glycoprotein. Antibody levels were reduced relative to plasma following elution from DBS. Quantitative results from DBS samples were highly correlated with values from plasma (r2 = 0.98), allowing for extrapolation using DBS results to accurately estimate plasma antibody levels. High concordance between plasma and fingerpick DBS was observed in PCR-confirmed COVID-19 patients tested 90 days or more after the diagnosis (45/46 matched; 1/46 mismatched plasma vs. DBS). The assessment of antibody responses to SARS-CoV-2 using DBS may be feasible using a quantitative anti-S assay, although false negatives may rarely occur in those with very low antibody levels