OBJECTIVE To describe the demographics, clinical presentation, proportion of co-infection with hu... more OBJECTIVE To describe the demographics, clinical presentation, proportion of co-infection with human immunodeficiency virus (HIV), and treatment of patients with ocular syphilis seen at the ophthalmology department of 2 tertiary centres in Montreal, Canada. DESIGN Retrospective case series. PARTICIPANTS AND METHODS A total of 169 eyes of 115 patients, seen between 2000 and 2015, with a positive syphilis treponemal serology and a likely syphilis-related ophthalmologic diagnosis. Subgroup analysis was performed between HIV-infected and HIV-uninfected patients. RESULTS Mean age of onset was 55 years, and 79% were male. Mean presenting logMAR visual acuity was 0.7. HIV status was available for 66%, of whom 49% were HIV-infected. The anatomical ocular diagnoses included isolated anterior uveitis (18%) and posterior segment involvement (42%). Both eyes were affected in 47%. Lumbar puncture (LP) was performed in 55%, of whom 22% had a positive cerebrospinal fluid (CSF) Venereal Disease Research Laboratory (VDRL) test. Antibiotherapy, consisting of intravenous penicillin alone or in addition to intramuscular benzathine penicillin, was administered in 65 patients (69%). Treatment allowed a visual improvement of -0.23 logMAR. HIV-infected patients were younger men (p < 0.01) and had more abnormal CSF analysis (p = 0.02), but there were no statistically significant differences in the anatomical location of ocular inflammation or visual function improvement. CONCLUSIONS Given its varied presentations, syphilis must always be part of the differential diagnosis of intraocular inflammation. HIV testing and an LP are required in the evaluation of ocular syphilis, which should be treated as neurosyphilis with the appropriate regimen.
The rapid confirmatory Bio-Rad Geenius HIV 1/2 assay was evaluated as an alternative to the HIV-1... more The rapid confirmatory Bio-Rad Geenius HIV 1/2 assay was evaluated as an alternative to the HIV-1 Western blot (WB) confirmatory assay. A total of 370 retrospective samples collected from 356 patients were tested. Sensitivity of the Geenius assay to detect HIV-1 and HIV-2 infections was 100% and 97%, respectively, and that of the WB assay was 86% and 39%, respectively. Geenius reduced the number of indeterminate results by 85% and exhibited a differentiation capacity for HIV-1 and HIV-2 of 100% and 89%, respectively. Three of 10 patients presenting with an early HIV infection (1 to 2 weeks before seroconversion by WB) were positive using Geenius. None of the HIV-negative samples were positive using Geenius or WB. However, 7% and 10% of them were indeterminate with Geenius and WB, respectively, leading to a specificity rate of 93% for Geenius and 90% for WB. Ninety cadaveric samples (54 negative, 23 HIV-1 positive, and 3 HIV-1 indeterminate) were tested with Geenius, leading to a sen...
Objectives To compare the prevalence of HIV, hepatitis C virus (HCV) infections, and related risk... more Objectives To compare the prevalence of HIV, hepatitis C virus (HCV) infections, and related risky behaviours among inmates in Quebec's provincial prisons between 2003 and 2014-2015. Methods Cross-sectional data were anonymously collected from May 2014 to March 2015 for men (n = 1315) and women (n = 250) and combined with data collected in 2003 to evaluate trends in the last decade. Participants completed a questionnaire and provided saliva samples. The data from the 2003 and 2014-2015 surveys were merged for statistical analysis. Results HIV prevalence was stable between 2003 and 2014-2015 for men (2.4% vs. 1.8%, p = 0.4), whereas it decreased for women (8.8% vs. 0.8%, p < 0.001). HCV prevalence decreased between 2003 and 2014-2015 for both men (16.6% vs. 11.9%, p < 0.001) and women (29.2% vs. 19.2%, p = 0.02). HIV and HCV prevalence were higher among people who inject drugs (PWID), for both sexes and both studies. PWID-specific prevalence did not change between 2003 and 2014-2015, except for a decrease in HIV prevalence in PWID women. However, the proportion of prisoners reporting a history of injection drug use outside prison was lower in 2014-2015 than in 2003 for men (19.8% vs. 27.7%, p < 0.0001) and women (28.6% vs. 42.6%, p = 0.002). The lower proportion of PWID inmates in 2014-2015 compared to 2003 explained in large part the decrease in HIV and HCV prevalence. Despite the decrease in prevalence, HIV and HCV infections among incarcerated individuals still represent a major public health problem due to the sizable increase of individuals in Quebec's correctional system over the same period. Objectif Comparer la prévalence des infections au VIH, l'hépatite C (VHC) et les comportements à risque chez les individus incarcérés dans les prisons provinciales du Québec en 2003 et 2014-2015. Méthodes Les données transversales ont été collectées entre mai 2014 et mars 2015 chez les hommes (n = 1315) et les femmes (n = 250). Un questionnaire a été administré et un échantillon de salive recueilli. Les données recueillies ont ensuite été combinées aux données de 2003 pour les analyses statistiques.
ObjectivesThe objectives of this study were: (1) to examine the correlates of HIV positivity amon... more ObjectivesThe objectives of this study were: (1) to examine the correlates of HIV positivity among participants who injected drugs and engaged in sex work (PWID-SWs) in the SurvUDI network between 2004 and 2016, after stratification by sex, and (2) to compare these correlates with those of sexually active participants who did not engage in sex work (PWID non-SWs).Design and settingThis biobehavioural survey is an open cohort of services where participants who had injected in the past 6 months were recruited mainly through harm reduction programmes in Eastern Central Canada.ParticipantsData from 5476 participants (9223 visits in total; 785 not included in multivariate analyses due to missing values) were included.MethodsParticipants completed an interviewer-administered questionnaire and provided saliva samples for anti-HIV antibody testing. Generalised estimating equations taking into account multiple participations were used.ResultsBaseline HIV prevalence was higher among SWs compa...
Although reverse sequence algorithms (RSA) for syphilis screening are performing well, they still... more Although reverse sequence algorithms (RSA) for syphilis screening are performing well, they still have to rely on treponemal confirmatory tests at least for sera reactive by enzyme immunoassay/chemiluminescence immunoassay (EIA/CIA) and unreactive by rapid plasma reagin (RPR). Quebec's laboratory network previously showed that 3.3% of EIA/CIA reactive and weakly-reactive RPR samples (RPR titer of 1 to 4) would have been misclassified as syphilis cases if a treponemal confirmatory test had not been performed. To correlate the magnitude of signal-to-cutoff (S/CO) ratios of the 4 most used commercial first-line EIA/CIA kits in Quebec with syphilis confirmation results and establish a S/CO value above which treponemal confirmation would not be required. Serum samples from previously undiagnosed individuals (n = 7 404) obtained between January 2014 and February 2017 that were reactive by EIA/CIA and either negative by RPR or reactive with a low titer (1 to 4) were included in the stu...
Identifying recent HIV-1 infections is crucial for monitoring HIV-1 incidence and optimizing publ... more Identifying recent HIV-1 infections is crucial for monitoring HIV-1 incidence and optimizing public health prevention efforts. To identify recent HIV-1 infections, we evaluated and compared the performance of 4 sequence-based diversity measures including percent diversity, percent complexity, Shannon entropy and number of haplotypes targeting 13 genetic segments within the env gene of HIV-1. A total of 597 diagnostic samples obtained in 2013 and 2015 from recently and chronically HIV-1 infected individuals were selected. From the selected samples, 249 (134 from recent versus 115 from chronic infections) env coding regions, including V1-C5 of gp120 and the gp41 ectodomain of HIV-1, were successfully amplified and sequenced by next generation sequencing (NGS) using the Illumina MiSeq platform. The ability of the four sequence-based diversity measures to correctly identify recent HIV infections was evaluated using the frequency distribution curves, median and interquartile range and ar...
Diagnostic Microbiology and Infectious Disease, 2011
We evaluated the seroprevalence of 10 zoonotic agents among the general population (15 years old ... more We evaluated the seroprevalence of 10 zoonotic agents among the general population (15 years old and over) of Eastmain and Wemindji, James Bay, Quebec, in 2007. Overall seroprevalence rates were similar between the 2 communities. Nearly half the individuals tested (n = 251; 146 women, 105 men) were seropositive (n = 115) for at least one zoonosis. The highest seroprevalence rates were for Leptospira sp. (23%), Francisella tularensis (17%), and the California serogroup viruses (JC and SSH viruses) (10%). The other zoonoses (Toxoplasma gondii, Coxiella burnetii, Echinococcus granulosus, Toxocara canis, and Trichinella sp.) had seroprevalence rates ≤5%; no exposures were identified to hantaviruses (Sin Nombre virus). Overall, seropositivity was related to age, gender, hunting, and owning a dog. There was no medical history suggestive of overt diseases. Nonetheless, physicians should consider these agents when confronted with difficult or confusing diagnoses. In particular, the bacterial zoonoses should be ruled out in individuals with high or prolonged fever.
PROCESS STATEMENT The development of these recommendations arose in the spring of 2009 under the ... more PROCESS STATEMENT The development of these recommendations arose in the spring of 2009 under the support and recommendation of the Canadian Public Health Laboratory Network (CPHLN). The initial group was formed of a federal co-chair (RT), a provincial co-chair (MM) and a CPHLN secretariat lead (SR). An initial environmental scan was performed in 2009, which was published in August 2011 (R Tsang, SM Radons, M Morshed. Laboratory diagnosis of syphilis: A survey to examine the range of tests used in Canada. Can J Infect Dis Med Microbiol 2011;22[3]:83-87). National representation was added to the working group in 2010, including laboratory scientists from the provincial pub-lic health laboratories, STI clinicians, epidemiologists and researchers. The group divided into smaller groups for the drafting of each chapter, which was written and presented back to the larger group. Once the document was finalized by the Syphilis Working Group, it was
The SARS-CoV-2 virus is responsible for the coronavirus disease 2019 (COVID-19) pandemic, infecti... more The SARS-CoV-2 virus is responsible for the coronavirus disease 2019 (COVID-19) pandemic, infecting millions of people and causing hundreds of thousands of deaths. The Spike glycoproteins of SARS-CoV-2 mediates viral entry and is the main target for neutralizing antibodies. Understanding the antibody response directed against SARS-CoV-2 is crucial for the development of vaccine, therapeutic and public health interventions. Here we perform a cross-sectional study on 106 different SARS-CoV-2-infected individuals to evaluate humoral responses against SARS-CoV-2 Spike. The vast majority of infected individuals elicits anti-Spike antibodies within 2 weeks after the onset of symptoms. The levels of receptor-binding domain (RBD)-specific IgG persist overtime, while the levels of anti-RBD IgM decrease after symptoms resolution. While most of individuals develop neutralizing antibodies within two weeks of infection, the level of neutralizing activity is significantly decreased over time. Our results highlight the importance of studying the persistence of neutralizing activity upon natural SARS-CoV-2 infection.
Background Laboratory diagnostic of syphilis is based on both treponemal and non-treponemal assay... more Background Laboratory diagnostic of syphilis is based on both treponemal and non-treponemal assays. While automated treponemal assays are available, non-treponemal antibody testing continue to require extensive hands on time. The BioPlex 2200 Syphilis Total & RPR assay by Bio-Rad Laboratories is a fully automated assay that detects both treponemal and non-treponemal antibodies with on board RPR titer capability. Methods We compared the BioPlex Total & RPR assay with the BiopPex IgG assay and with the Wampole Impact RPR card test for the treponemal and non-treponemal antibodies detection respectively. A total of 504 prospective sera sent to our laboratory for syphilis testing were tested with both BioPlex assays to establish agreement of treponemal results. Also, a panel of 52 sera with known titer values was provided by our reference laboratory. These sera were tested with the BioPlex Total & RPR assay and the manual Wampole RPR card to compare titer results, using essential agreement within 1 dilution range and correlation of log2 transformed titer values with Spearman coefficient. Results Of the 504 sera tested, 112 were positive for treponemal antibodies with BioPlex Total & RPR and 109 with BioPlex IgG. Positive, negative and overall agreements were 95% (104/109)(95% CI [89%, 98%]), 98% (387/395)(95% CI [96%, 99%]) and 97% (491/504)(95% CI [95%, 99%]) respectively for these sera. Essential agreement within 1 dilution of quantitative RPR titer results for the 52 sera panel was 90% and the Spearman correlation coefficient of titers obtained with the two assays was 0.926 with a p <0.001. Conclusion The BioPlex 2200 Syphilis Total & RPR assay is a fully automated assay that compares favorably with the BioPlex 2200 Syphilis IgG assay and that yields non treponemal titers that correlates favorably with a traditional manual RPR card test. Reliable automated non treponemal assays are needed. Disclosure No significant relationships.
Background. Current guidelines only recommend screening for gonorrhea (GC) and chlamydia (CT) at ... more Background. Current guidelines only recommend screening for gonorrhea (GC) and chlamydia (CT) at extragenital sites of exposure in men who have sex with men (MSM). With Medicaid reimbursement for GC/CT nucleic acid amplification testing (NAAT) at approximately $48/test, expanding testing to women requires a value assessment. We report the prevalence of extragenital GC/CT in women with extragenital exposure, determine the proportion of disease missed by urogenital NAAT, and estimate additional cost per infection identified by extragenital testing in women vs MSM. Methods. We conducted a retrospective analysis of women undergoing extragenital NAAT for GC and CT at Denver Metro Health Clinic. Data were analyzed for all women with extragenital testing from 9/11
Background: HIV-1 transmitted/founder viruses (TF) are selected during the acute phase of infecti... more Background: HIV-1 transmitted/founder viruses (TF) are selected during the acute phase of infection from a multitude of virions present during transmission. They possess the capacity to establish infection and viral dissemination in a new host. Deciphering the discrete genetic determinant of infectivity in their envelope may provide clues for vaccine design. Methods: One hundred twenty-six clade B HIV-1 consensus envelope sequences from untreated acute and early infected individuals were compared to 105 sequences obtained from chronically infected individuals using next generation sequencing and molecular analyses. Results: We identified an envelope amino acid signature associated with TF viruses. They are more likely to have an isoleucine (I) in position 841 instead of an arginine (R). This mutation of R to I (R841I) in the gp41 cytoplasmic tail (gp41CT), specifically in lentivirus lytic peptides segment 1 (LLP-1), is significantly enriched compared to chronic viruses (OR = 0.2, 95...
The identification of transmission clusters (TCs) of HIV-1 using phylogenetic analyses can provid... more The identification of transmission clusters (TCs) of HIV-1 using phylogenetic analyses can provide insights into viral transmission network and help improve prevention strategies. We compared the use of partial HIV-1 envelope fragment of 1,070 bp with its loop 3 (108 bp) to determine its utility in inferring HIV-1 transmission clustering. Serum samples of recently (n = 106) and chronically (n = 156) HIV-1-infected patients with status confirmed were sequenced. HIV-1 envelope nucleotide-based phylogenetic analyses were used to infer HIV-1 TCs. Those were constructed using ClusterPickerGUI_1.2.3 considering a pairwise genetic distance of £10% threshold. Logistic regression analyses were used to examine the relationship between the demographic factors that were likely associated with HIV-1 clustering. Ninety-eight distinct consensus envelope sequences were subjected to phylogenetic analyses. Using a partial envelope fragment sequence, 42 sequences were grouped into 15 distinct small TCs while the V3 loop reproduces 10 clusters. The agreement between the partial envelope and the V3 loop fragments was significantly moderate with a Cohen's kappa (j) coefficient of 0.59, p < .00001. The mean age (<38.8 years) and HIV-1 B subtype are two factors identified that were significantly associated with HIV-1 transmission clustering in the cohort, odds ratio (OR) = 0.25, 95% confidence interval (CI, 0.04-0.66), p = .002 and OR: 0.17, 95% CI (0.10-0.61), p = .011, respectively. The present study confirms that a partial fragment of the HIV-1 envelope sequence is a better predictor of transmission clustering. However, the loop 3 segment may be useful in screening purposes and may be more amenable to integration in surveillance programs.
Canada eliminated measles in 1998. We conducted a sero-epidemiology study to estimate population ... more Canada eliminated measles in 1998. We conducted a sero-epidemiology study to estimate population immunity to measles in the province of Ontario, Canada and to identify groups at higher risk of outbreaks. We used a previously developed modified enzyme immunoassay to test 1,199 residual sera from patients aged 1-39 years. We re-tested negative and equivocal sera using a plaque reduction neutralization assay. We interpreted our results in the context of Ontario's immunization program and vaccine coverage data. Of 1,199 sera, 1035 (86.3%, 95% confidence interval (CI) 84.4, 88.2) were above the measles threshold for protection, 70 (5.8%, 95% CI 4.5, 7.2) were equivocal and 94 (7.8%, 95% CI 6.3, 9.4) were negative. The proportion of positive sera was highest for those 1-5 years, with 180/199 (90.5%, 95% CI 86.4, 94.5) positive sera, and lowest for those age 12-19 years, at 158/199 (79.4%, 95% CI 73.8, 85.0). Adjusted for age, females were more likely than males to have antibody titers above the threshold of protection (odds ratio = 1.60, 95% CI 1.14, 2.24). Most of the study cohort were eligible for two measles vaccine doses, and vaccine uptake in Ontario is >90% for school-aged cohorts. We observed a higher than expected proportion of sera with antibody levels below the threshold of protection, suggesting that immunity in some Ontario age-groups may be waning, despite high vaccine coverage. Alternatively, the traditional measles correlates of protection may not be an appropriate measure of population protection in measles-eliminated settings.
Poster presentations their frequent high risk exposures. HIV transmission among PWID appears to b... more Poster presentations their frequent high risk exposures. HIV transmission among PWID appears to be occurring at a rapid pace. Essential interventions are needed to slow transmission. Tuberculosis Among HiV PosiTiVe cAses in umn HosPiTAl TAnsen-WesTern nePAl
Accurate and practical biologic tools to estimate HIV incidence is crucial to better monitor the ... more Accurate and practical biologic tools to estimate HIV incidence is crucial to better monitor the epidemic and evaluate the effectiveness of HIV prevention and treatment programs. We evaluated two avidity assays to measure recent HIV infection: the Sedia HIV-1 LAg-Avidity EIA (Sedia Biosciences, Portland) and the Centers for Disease Control and Prevention (CDC)-modified Bio-Rad-Avidity assay (Bio-Rad Laboratories, Mississauga, ON). Longitudinal specimens (n = 473) obtained from 123 treatment-naive seroconverted individuals enrolled in the Primary HIV-1 Infection (PHI) cohort of Quebec were used to determine the average time an individual is considered to be recently infected (mean duration of recent infection; MDRI), for the two avidity assays alone and in combination using a nonparametric survival method analysis. A total of 420 specimens from individuals with established HIV infection (90 individuals from the PHI cohort of Quebec and 330 individuals from the Laboratoire de santé publique du Quebec (LSPQ) serobank) were also tested to investigate false recency rate (FRR). The CDC-modified Bio-Rad-Avidity gave an estimated MDRI of 234 days (95% CI 220-249) at the avidity index cutoff of 30% while the Sedia-LAg-Avidity assay gave an estimated MDRI of 120 days (95% CI 109-132) at the normalized optical density (ODn) cutoff of 1.5. The FRR among individuals with established HIV infection was 10.2% (7.5%-13.5%) with the CDC-modified Bio-Rad-Avidity assay as compared to 6.0% (3.9%-8.7%) with the Sedia-LAg-Avidity assay. When optimizing a multiassay algorithm (MAA) that includes sequentially the CDC-modified Bio-Rad-Avidity assay then the Sedia-LAg-Avidity assay EIA (avidity index/ODn: 30%/1.7), the MDRI was 136 days (95% CI 123-148) and the FRR, 3.3% (95% CI 1.8-5.6). Multiassay algorithms that include the CDC-modified Bio-Rad-Avidity assay and the Sedia-LAg-Avidity assay performed better than each avidity assay alone. Such 2-assay algorithm that starts with the CDC-modified Bio-Rad-Avidity assay followed by the Sedia-LAg-Avidity assay allowed a better classification of HIV-1 infections.
This study was undertaken to search for the presence of immunoglobulin G (IgG)-binding proteins i... more This study was undertaken to search for the presence of immunoglobulin G (IgG)-binding proteins in Streptococcus suis, an important swine pathogen. Whole bacterial cells were incubated with human or pig IgG conjugated to gold particles and examined by transmission electron microscopy. Cells of some S. suis strains were labelled as were cells of the positive control strain, Staphylococcus aureus Cowan I. Binding of pig and human IgG to five different bacterial species of group D streptococci, to reference strains representing the 29 capsular types of S. suis, and to 12 S. suis capsular type 2 strains was then examined using Western blotting. All strains interacted with pig and human IgG, although the binding profiles were slightly different. A 52 kDa protein was observed in all capsular types of S. suis. This protein, absent in other group D streptococcal species, was observed in all capsular type 2 isolates originating from diseased or clinically healthy pigs, and was shown to bind ...
OBJECTIVE To describe the demographics, clinical presentation, proportion of co-infection with hu... more OBJECTIVE To describe the demographics, clinical presentation, proportion of co-infection with human immunodeficiency virus (HIV), and treatment of patients with ocular syphilis seen at the ophthalmology department of 2 tertiary centres in Montreal, Canada. DESIGN Retrospective case series. PARTICIPANTS AND METHODS A total of 169 eyes of 115 patients, seen between 2000 and 2015, with a positive syphilis treponemal serology and a likely syphilis-related ophthalmologic diagnosis. Subgroup analysis was performed between HIV-infected and HIV-uninfected patients. RESULTS Mean age of onset was 55 years, and 79% were male. Mean presenting logMAR visual acuity was 0.7. HIV status was available for 66%, of whom 49% were HIV-infected. The anatomical ocular diagnoses included isolated anterior uveitis (18%) and posterior segment involvement (42%). Both eyes were affected in 47%. Lumbar puncture (LP) was performed in 55%, of whom 22% had a positive cerebrospinal fluid (CSF) Venereal Disease Research Laboratory (VDRL) test. Antibiotherapy, consisting of intravenous penicillin alone or in addition to intramuscular benzathine penicillin, was administered in 65 patients (69%). Treatment allowed a visual improvement of -0.23 logMAR. HIV-infected patients were younger men (p < 0.01) and had more abnormal CSF analysis (p = 0.02), but there were no statistically significant differences in the anatomical location of ocular inflammation or visual function improvement. CONCLUSIONS Given its varied presentations, syphilis must always be part of the differential diagnosis of intraocular inflammation. HIV testing and an LP are required in the evaluation of ocular syphilis, which should be treated as neurosyphilis with the appropriate regimen.
The rapid confirmatory Bio-Rad Geenius HIV 1/2 assay was evaluated as an alternative to the HIV-1... more The rapid confirmatory Bio-Rad Geenius HIV 1/2 assay was evaluated as an alternative to the HIV-1 Western blot (WB) confirmatory assay. A total of 370 retrospective samples collected from 356 patients were tested. Sensitivity of the Geenius assay to detect HIV-1 and HIV-2 infections was 100% and 97%, respectively, and that of the WB assay was 86% and 39%, respectively. Geenius reduced the number of indeterminate results by 85% and exhibited a differentiation capacity for HIV-1 and HIV-2 of 100% and 89%, respectively. Three of 10 patients presenting with an early HIV infection (1 to 2 weeks before seroconversion by WB) were positive using Geenius. None of the HIV-negative samples were positive using Geenius or WB. However, 7% and 10% of them were indeterminate with Geenius and WB, respectively, leading to a specificity rate of 93% for Geenius and 90% for WB. Ninety cadaveric samples (54 negative, 23 HIV-1 positive, and 3 HIV-1 indeterminate) were tested with Geenius, leading to a sen...
Objectives To compare the prevalence of HIV, hepatitis C virus (HCV) infections, and related risk... more Objectives To compare the prevalence of HIV, hepatitis C virus (HCV) infections, and related risky behaviours among inmates in Quebec's provincial prisons between 2003 and 2014-2015. Methods Cross-sectional data were anonymously collected from May 2014 to March 2015 for men (n = 1315) and women (n = 250) and combined with data collected in 2003 to evaluate trends in the last decade. Participants completed a questionnaire and provided saliva samples. The data from the 2003 and 2014-2015 surveys were merged for statistical analysis. Results HIV prevalence was stable between 2003 and 2014-2015 for men (2.4% vs. 1.8%, p = 0.4), whereas it decreased for women (8.8% vs. 0.8%, p < 0.001). HCV prevalence decreased between 2003 and 2014-2015 for both men (16.6% vs. 11.9%, p < 0.001) and women (29.2% vs. 19.2%, p = 0.02). HIV and HCV prevalence were higher among people who inject drugs (PWID), for both sexes and both studies. PWID-specific prevalence did not change between 2003 and 2014-2015, except for a decrease in HIV prevalence in PWID women. However, the proportion of prisoners reporting a history of injection drug use outside prison was lower in 2014-2015 than in 2003 for men (19.8% vs. 27.7%, p < 0.0001) and women (28.6% vs. 42.6%, p = 0.002). The lower proportion of PWID inmates in 2014-2015 compared to 2003 explained in large part the decrease in HIV and HCV prevalence. Despite the decrease in prevalence, HIV and HCV infections among incarcerated individuals still represent a major public health problem due to the sizable increase of individuals in Quebec's correctional system over the same period. Objectif Comparer la prévalence des infections au VIH, l'hépatite C (VHC) et les comportements à risque chez les individus incarcérés dans les prisons provinciales du Québec en 2003 et 2014-2015. Méthodes Les données transversales ont été collectées entre mai 2014 et mars 2015 chez les hommes (n = 1315) et les femmes (n = 250). Un questionnaire a été administré et un échantillon de salive recueilli. Les données recueillies ont ensuite été combinées aux données de 2003 pour les analyses statistiques.
ObjectivesThe objectives of this study were: (1) to examine the correlates of HIV positivity amon... more ObjectivesThe objectives of this study were: (1) to examine the correlates of HIV positivity among participants who injected drugs and engaged in sex work (PWID-SWs) in the SurvUDI network between 2004 and 2016, after stratification by sex, and (2) to compare these correlates with those of sexually active participants who did not engage in sex work (PWID non-SWs).Design and settingThis biobehavioural survey is an open cohort of services where participants who had injected in the past 6 months were recruited mainly through harm reduction programmes in Eastern Central Canada.ParticipantsData from 5476 participants (9223 visits in total; 785 not included in multivariate analyses due to missing values) were included.MethodsParticipants completed an interviewer-administered questionnaire and provided saliva samples for anti-HIV antibody testing. Generalised estimating equations taking into account multiple participations were used.ResultsBaseline HIV prevalence was higher among SWs compa...
Although reverse sequence algorithms (RSA) for syphilis screening are performing well, they still... more Although reverse sequence algorithms (RSA) for syphilis screening are performing well, they still have to rely on treponemal confirmatory tests at least for sera reactive by enzyme immunoassay/chemiluminescence immunoassay (EIA/CIA) and unreactive by rapid plasma reagin (RPR). Quebec's laboratory network previously showed that 3.3% of EIA/CIA reactive and weakly-reactive RPR samples (RPR titer of 1 to 4) would have been misclassified as syphilis cases if a treponemal confirmatory test had not been performed. To correlate the magnitude of signal-to-cutoff (S/CO) ratios of the 4 most used commercial first-line EIA/CIA kits in Quebec with syphilis confirmation results and establish a S/CO value above which treponemal confirmation would not be required. Serum samples from previously undiagnosed individuals (n = 7 404) obtained between January 2014 and February 2017 that were reactive by EIA/CIA and either negative by RPR or reactive with a low titer (1 to 4) were included in the stu...
Identifying recent HIV-1 infections is crucial for monitoring HIV-1 incidence and optimizing publ... more Identifying recent HIV-1 infections is crucial for monitoring HIV-1 incidence and optimizing public health prevention efforts. To identify recent HIV-1 infections, we evaluated and compared the performance of 4 sequence-based diversity measures including percent diversity, percent complexity, Shannon entropy and number of haplotypes targeting 13 genetic segments within the env gene of HIV-1. A total of 597 diagnostic samples obtained in 2013 and 2015 from recently and chronically HIV-1 infected individuals were selected. From the selected samples, 249 (134 from recent versus 115 from chronic infections) env coding regions, including V1-C5 of gp120 and the gp41 ectodomain of HIV-1, were successfully amplified and sequenced by next generation sequencing (NGS) using the Illumina MiSeq platform. The ability of the four sequence-based diversity measures to correctly identify recent HIV infections was evaluated using the frequency distribution curves, median and interquartile range and ar...
Diagnostic Microbiology and Infectious Disease, 2011
We evaluated the seroprevalence of 10 zoonotic agents among the general population (15 years old ... more We evaluated the seroprevalence of 10 zoonotic agents among the general population (15 years old and over) of Eastmain and Wemindji, James Bay, Quebec, in 2007. Overall seroprevalence rates were similar between the 2 communities. Nearly half the individuals tested (n = 251; 146 women, 105 men) were seropositive (n = 115) for at least one zoonosis. The highest seroprevalence rates were for Leptospira sp. (23%), Francisella tularensis (17%), and the California serogroup viruses (JC and SSH viruses) (10%). The other zoonoses (Toxoplasma gondii, Coxiella burnetii, Echinococcus granulosus, Toxocara canis, and Trichinella sp.) had seroprevalence rates ≤5%; no exposures were identified to hantaviruses (Sin Nombre virus). Overall, seropositivity was related to age, gender, hunting, and owning a dog. There was no medical history suggestive of overt diseases. Nonetheless, physicians should consider these agents when confronted with difficult or confusing diagnoses. In particular, the bacterial zoonoses should be ruled out in individuals with high or prolonged fever.
PROCESS STATEMENT The development of these recommendations arose in the spring of 2009 under the ... more PROCESS STATEMENT The development of these recommendations arose in the spring of 2009 under the support and recommendation of the Canadian Public Health Laboratory Network (CPHLN). The initial group was formed of a federal co-chair (RT), a provincial co-chair (MM) and a CPHLN secretariat lead (SR). An initial environmental scan was performed in 2009, which was published in August 2011 (R Tsang, SM Radons, M Morshed. Laboratory diagnosis of syphilis: A survey to examine the range of tests used in Canada. Can J Infect Dis Med Microbiol 2011;22[3]:83-87). National representation was added to the working group in 2010, including laboratory scientists from the provincial pub-lic health laboratories, STI clinicians, epidemiologists and researchers. The group divided into smaller groups for the drafting of each chapter, which was written and presented back to the larger group. Once the document was finalized by the Syphilis Working Group, it was
The SARS-CoV-2 virus is responsible for the coronavirus disease 2019 (COVID-19) pandemic, infecti... more The SARS-CoV-2 virus is responsible for the coronavirus disease 2019 (COVID-19) pandemic, infecting millions of people and causing hundreds of thousands of deaths. The Spike glycoproteins of SARS-CoV-2 mediates viral entry and is the main target for neutralizing antibodies. Understanding the antibody response directed against SARS-CoV-2 is crucial for the development of vaccine, therapeutic and public health interventions. Here we perform a cross-sectional study on 106 different SARS-CoV-2-infected individuals to evaluate humoral responses against SARS-CoV-2 Spike. The vast majority of infected individuals elicits anti-Spike antibodies within 2 weeks after the onset of symptoms. The levels of receptor-binding domain (RBD)-specific IgG persist overtime, while the levels of anti-RBD IgM decrease after symptoms resolution. While most of individuals develop neutralizing antibodies within two weeks of infection, the level of neutralizing activity is significantly decreased over time. Our results highlight the importance of studying the persistence of neutralizing activity upon natural SARS-CoV-2 infection.
Background Laboratory diagnostic of syphilis is based on both treponemal and non-treponemal assay... more Background Laboratory diagnostic of syphilis is based on both treponemal and non-treponemal assays. While automated treponemal assays are available, non-treponemal antibody testing continue to require extensive hands on time. The BioPlex 2200 Syphilis Total & RPR assay by Bio-Rad Laboratories is a fully automated assay that detects both treponemal and non-treponemal antibodies with on board RPR titer capability. Methods We compared the BioPlex Total & RPR assay with the BiopPex IgG assay and with the Wampole Impact RPR card test for the treponemal and non-treponemal antibodies detection respectively. A total of 504 prospective sera sent to our laboratory for syphilis testing were tested with both BioPlex assays to establish agreement of treponemal results. Also, a panel of 52 sera with known titer values was provided by our reference laboratory. These sera were tested with the BioPlex Total & RPR assay and the manual Wampole RPR card to compare titer results, using essential agreement within 1 dilution range and correlation of log2 transformed titer values with Spearman coefficient. Results Of the 504 sera tested, 112 were positive for treponemal antibodies with BioPlex Total & RPR and 109 with BioPlex IgG. Positive, negative and overall agreements were 95% (104/109)(95% CI [89%, 98%]), 98% (387/395)(95% CI [96%, 99%]) and 97% (491/504)(95% CI [95%, 99%]) respectively for these sera. Essential agreement within 1 dilution of quantitative RPR titer results for the 52 sera panel was 90% and the Spearman correlation coefficient of titers obtained with the two assays was 0.926 with a p <0.001. Conclusion The BioPlex 2200 Syphilis Total & RPR assay is a fully automated assay that compares favorably with the BioPlex 2200 Syphilis IgG assay and that yields non treponemal titers that correlates favorably with a traditional manual RPR card test. Reliable automated non treponemal assays are needed. Disclosure No significant relationships.
Background. Current guidelines only recommend screening for gonorrhea (GC) and chlamydia (CT) at ... more Background. Current guidelines only recommend screening for gonorrhea (GC) and chlamydia (CT) at extragenital sites of exposure in men who have sex with men (MSM). With Medicaid reimbursement for GC/CT nucleic acid amplification testing (NAAT) at approximately $48/test, expanding testing to women requires a value assessment. We report the prevalence of extragenital GC/CT in women with extragenital exposure, determine the proportion of disease missed by urogenital NAAT, and estimate additional cost per infection identified by extragenital testing in women vs MSM. Methods. We conducted a retrospective analysis of women undergoing extragenital NAAT for GC and CT at Denver Metro Health Clinic. Data were analyzed for all women with extragenital testing from 9/11
Background: HIV-1 transmitted/founder viruses (TF) are selected during the acute phase of infecti... more Background: HIV-1 transmitted/founder viruses (TF) are selected during the acute phase of infection from a multitude of virions present during transmission. They possess the capacity to establish infection and viral dissemination in a new host. Deciphering the discrete genetic determinant of infectivity in their envelope may provide clues for vaccine design. Methods: One hundred twenty-six clade B HIV-1 consensus envelope sequences from untreated acute and early infected individuals were compared to 105 sequences obtained from chronically infected individuals using next generation sequencing and molecular analyses. Results: We identified an envelope amino acid signature associated with TF viruses. They are more likely to have an isoleucine (I) in position 841 instead of an arginine (R). This mutation of R to I (R841I) in the gp41 cytoplasmic tail (gp41CT), specifically in lentivirus lytic peptides segment 1 (LLP-1), is significantly enriched compared to chronic viruses (OR = 0.2, 95...
The identification of transmission clusters (TCs) of HIV-1 using phylogenetic analyses can provid... more The identification of transmission clusters (TCs) of HIV-1 using phylogenetic analyses can provide insights into viral transmission network and help improve prevention strategies. We compared the use of partial HIV-1 envelope fragment of 1,070 bp with its loop 3 (108 bp) to determine its utility in inferring HIV-1 transmission clustering. Serum samples of recently (n = 106) and chronically (n = 156) HIV-1-infected patients with status confirmed were sequenced. HIV-1 envelope nucleotide-based phylogenetic analyses were used to infer HIV-1 TCs. Those were constructed using ClusterPickerGUI_1.2.3 considering a pairwise genetic distance of £10% threshold. Logistic regression analyses were used to examine the relationship between the demographic factors that were likely associated with HIV-1 clustering. Ninety-eight distinct consensus envelope sequences were subjected to phylogenetic analyses. Using a partial envelope fragment sequence, 42 sequences were grouped into 15 distinct small TCs while the V3 loop reproduces 10 clusters. The agreement between the partial envelope and the V3 loop fragments was significantly moderate with a Cohen's kappa (j) coefficient of 0.59, p < .00001. The mean age (<38.8 years) and HIV-1 B subtype are two factors identified that were significantly associated with HIV-1 transmission clustering in the cohort, odds ratio (OR) = 0.25, 95% confidence interval (CI, 0.04-0.66), p = .002 and OR: 0.17, 95% CI (0.10-0.61), p = .011, respectively. The present study confirms that a partial fragment of the HIV-1 envelope sequence is a better predictor of transmission clustering. However, the loop 3 segment may be useful in screening purposes and may be more amenable to integration in surveillance programs.
Canada eliminated measles in 1998. We conducted a sero-epidemiology study to estimate population ... more Canada eliminated measles in 1998. We conducted a sero-epidemiology study to estimate population immunity to measles in the province of Ontario, Canada and to identify groups at higher risk of outbreaks. We used a previously developed modified enzyme immunoassay to test 1,199 residual sera from patients aged 1-39 years. We re-tested negative and equivocal sera using a plaque reduction neutralization assay. We interpreted our results in the context of Ontario's immunization program and vaccine coverage data. Of 1,199 sera, 1035 (86.3%, 95% confidence interval (CI) 84.4, 88.2) were above the measles threshold for protection, 70 (5.8%, 95% CI 4.5, 7.2) were equivocal and 94 (7.8%, 95% CI 6.3, 9.4) were negative. The proportion of positive sera was highest for those 1-5 years, with 180/199 (90.5%, 95% CI 86.4, 94.5) positive sera, and lowest for those age 12-19 years, at 158/199 (79.4%, 95% CI 73.8, 85.0). Adjusted for age, females were more likely than males to have antibody titers above the threshold of protection (odds ratio = 1.60, 95% CI 1.14, 2.24). Most of the study cohort were eligible for two measles vaccine doses, and vaccine uptake in Ontario is >90% for school-aged cohorts. We observed a higher than expected proportion of sera with antibody levels below the threshold of protection, suggesting that immunity in some Ontario age-groups may be waning, despite high vaccine coverage. Alternatively, the traditional measles correlates of protection may not be an appropriate measure of population protection in measles-eliminated settings.
Poster presentations their frequent high risk exposures. HIV transmission among PWID appears to b... more Poster presentations their frequent high risk exposures. HIV transmission among PWID appears to be occurring at a rapid pace. Essential interventions are needed to slow transmission. Tuberculosis Among HiV PosiTiVe cAses in umn HosPiTAl TAnsen-WesTern nePAl
Accurate and practical biologic tools to estimate HIV incidence is crucial to better monitor the ... more Accurate and practical biologic tools to estimate HIV incidence is crucial to better monitor the epidemic and evaluate the effectiveness of HIV prevention and treatment programs. We evaluated two avidity assays to measure recent HIV infection: the Sedia HIV-1 LAg-Avidity EIA (Sedia Biosciences, Portland) and the Centers for Disease Control and Prevention (CDC)-modified Bio-Rad-Avidity assay (Bio-Rad Laboratories, Mississauga, ON). Longitudinal specimens (n = 473) obtained from 123 treatment-naive seroconverted individuals enrolled in the Primary HIV-1 Infection (PHI) cohort of Quebec were used to determine the average time an individual is considered to be recently infected (mean duration of recent infection; MDRI), for the two avidity assays alone and in combination using a nonparametric survival method analysis. A total of 420 specimens from individuals with established HIV infection (90 individuals from the PHI cohort of Quebec and 330 individuals from the Laboratoire de santé publique du Quebec (LSPQ) serobank) were also tested to investigate false recency rate (FRR). The CDC-modified Bio-Rad-Avidity gave an estimated MDRI of 234 days (95% CI 220-249) at the avidity index cutoff of 30% while the Sedia-LAg-Avidity assay gave an estimated MDRI of 120 days (95% CI 109-132) at the normalized optical density (ODn) cutoff of 1.5. The FRR among individuals with established HIV infection was 10.2% (7.5%-13.5%) with the CDC-modified Bio-Rad-Avidity assay as compared to 6.0% (3.9%-8.7%) with the Sedia-LAg-Avidity assay. When optimizing a multiassay algorithm (MAA) that includes sequentially the CDC-modified Bio-Rad-Avidity assay then the Sedia-LAg-Avidity assay EIA (avidity index/ODn: 30%/1.7), the MDRI was 136 days (95% CI 123-148) and the FRR, 3.3% (95% CI 1.8-5.6). Multiassay algorithms that include the CDC-modified Bio-Rad-Avidity assay and the Sedia-LAg-Avidity assay performed better than each avidity assay alone. Such 2-assay algorithm that starts with the CDC-modified Bio-Rad-Avidity assay followed by the Sedia-LAg-Avidity assay allowed a better classification of HIV-1 infections.
This study was undertaken to search for the presence of immunoglobulin G (IgG)-binding proteins i... more This study was undertaken to search for the presence of immunoglobulin G (IgG)-binding proteins in Streptococcus suis, an important swine pathogen. Whole bacterial cells were incubated with human or pig IgG conjugated to gold particles and examined by transmission electron microscopy. Cells of some S. suis strains were labelled as were cells of the positive control strain, Staphylococcus aureus Cowan I. Binding of pig and human IgG to five different bacterial species of group D streptococci, to reference strains representing the 29 capsular types of S. suis, and to 12 S. suis capsular type 2 strains was then examined using Western blotting. All strains interacted with pig and human IgG, although the binding profiles were slightly different. A 52 kDa protein was observed in all capsular types of S. suis. This protein, absent in other group D streptococcal species, was observed in all capsular type 2 isolates originating from diseased or clinically healthy pigs, and was shown to bind ...
Uploads
Papers by Bouchra Serhir