COVID-19 vaccine uptake among people with HIV: identifying characteristics associated with vaccine hesitancy.

People with HIV (PWH) are at increased risk of COVID-19 infection. Both Canadian (NACI) and US (CDC) guidelines recommend that all PWH receive at least 2 doses of COVID-19 vaccine, and a booster. We examined vaccination uptake among PWH in Southern Alberta, Canada. Among adult PWH, we evaluated COVID-19 vaccination uptake between December 2020 and August 2022. Poisson regression models with robust variance (approximating log binomial models) estimated crude and adjusted prevalence ratios (aPR) and 95% confidence intervals (CI) for receiving (1) any vs. no vaccine, and (2) primary series with booster (≥ 3 vaccines) versus primary series without booster. Among 1885 PWH, 10% received no COVID-19 vaccinations, 37% < 3 vaccines and 54% received ≥ 3 vaccines. Females (vs. males) were less likely to receive a vaccine booster. Receiving no COVID-19 vaccines was associated with White ethnicity, unsuppressed HIV viral load (> 200 copies/mL), and using illegal substances. Factors associated with decreased booster uptake included being younger, Black (vs. White) ethnicity, substance use, lower educational attainment, and having an unsuppressed HIV viral load. COVID-19 booster uptake among PWH does not meet vaccine guidelines, and receipt of vaccines is unevenly distributed. Booster uptake is lowest among young females and marginalized individuals. Focused outreach is necessary to close this gap.

The changing use and program costs of HIV-related laboratory testing over 20 years in an HIV cohort.

PURPOSE OF REVIEW: The improved health of persons with HIV (PWH) resulting from antiretroviral therapy (ART) has led to recommendations for reduced laboratory monitoring. We studied, for all PWH in care over 20 years at the Southern Alberta Clinic (SAC), Canada, the changing use and results of HIV-specific laboratory testing [i.e., CD4+ testing, plasma HIV viral load (PVL), and genotypic antiretroviral resistance testing (GART)].In this descriptive retrospective longitudinal cohort observational study, we examined HIV-specific laboratory testing for all PWH from 2000 to 2020 within the context of HIV-related health outcomes, program costs, and mortality. RECENT FINDINGS: The number of PWH in care increased from 755 in 2000 to 2050 in 2020. Annual CD4+ testing per PWH increased from 2.7 per person in 2000 peaking to 3.5 in 2005 but decreasing to 1.4 by 2020. Annual PVL tests per PWH gradually decreased from 3.2 in 2000 to 2.0 in 2020. GART increased from 93 tests in 2000 to 315 in 2008 decreasing to 127 in 2020. Patients received GART at baseline, and after a viral breakthrough when indicated. Viral suppression rates for the population increased from 66 to 96%; median CD4+ cell count increased from 443 to 470 cells/µl, and overall morbidity decreased from 9.2 to 2.0% by 2020, respectively. Annual per patient laboratory costs decreased from a high of $302 in 2008 to $161 by 2020. SUMMARY: The reduced annual laboratory surveillance per PWH associated with modern ART resulted in modest cost savings and no apparent loss in quality of HIV care.

Seropositivity, Risks, and Morbidity From Varicella-Zoster Virus Infections in an Adult PWH Cohort From 2000-2020.

Background: Varicella-zoster virus (VZV) infection disproportionately affects people with HIV (PWH), primarily presenting as herpes zoster. However, VZV seroprevalence, its association with zoster, and clinical outcomes remain understudied in era of modern antiretroviral therapy (ART). We assessed VZV seroprevalence, rates of VZV illness, and associated health care costs in a large cohort of PWH over 20 years. Methods: We performed retrospective chart reviews of patients followed at a regional HIV clinic from January 1, 2000, to December 31, 2020. Serological, immunization, clinical, and costing data were extracted from in-house databases. VZV-related inpatient admissions, emergency department (ED), and urgent care (UC) visits were identified using relevant International Classification of Disease (ICD-10) codes and validated where possible by 2 physicians. Health care utilization costs were adjusted to 2020 Canadian dollars. Results: Of 3006 PWH, VZV serology was available for 2628; of these, 2503 (95.2%) were seropositive. Only 39% of known seronegative patients were subsequently immunized for varicella. During 29 768 years of patient follow-up, 38 hospitalizations and 138 ED/UC visits due to VZV infection were identified. Most occurred in VZV-seropositive PWH <50 years of age (82%) who were unimmunized (99.2%) and not on ART (64.8%). Nearly 25% of hospitalizations were due to laboratory-confirmed VZV meningitis/encephalitis. The average admission cost was CDN$33 001; the total measured cost of VZV illness was CDN$1 258 718. Conclusions: Despite ART and vaccines for chickenpox and shingles, VZV still caused significant costs and morbidity for PWH, occurring at younger ages and often as encephalitis/meningitis. Supporting ART adherence may reduce VZV illness and hospitalization costs in PWH, and the cost-effectiveness of expanding shingles vaccine use warrants further study.

HIV misdiagnosis: A root cause analysis leading to improvements in HIV diagnosis and patient care.

BACKGROUND: Standard diagnostic testing for HIV infection has traditionally relied on a high sensitivity HIV antibody screening test using an enzyme-linked immunosorbent assay (ELISA) followed by a high specificity antibody confirmatory test such as a Western Blot. Recently several of the screening assays have been enhanced with an ability to identify p24 antigen thereby narrowing the diagnostic window. OBJECTIVES: To explore the implications of enhanced HIV screening methods that may be leading to HIV misdiagnoses. STUDY DESIGN: A patient deemed to be an HIV infected 'elite controller' was found to be misdiagnosed when undergoing detailed investigations prior to initiating antiretroviral therapy. A root cause analysis was performed to identify the causative factors of this misdiagnosis. A retrospective review of all "elite controllers" in Alberta, Canada revealed challenges of current HIV testing algorithms. RESULTS: Technical and human factors were identified as being causative in this HIV misdiagnosis including (i) high rates of false reactive results on the Abbott ARCHITECT HIV-1&2 COMBO EIA, (ii) human error in reading the initial Western blot, (iii) HIV algorithmic directives in which confirmatory (Western blot) testing was not performed on a repeatedly reactive screen test. The outcome of this analysis identified opportunities for improvement, including implementation of a newly approved (automated) confirmatory assay and improved communication between the clinician and laboratory. CONCLUSIONS: HIV testing remains problematic despite significant advances in HIV test performance and algorithm development, presenting new and unexpected issues. Ensuring a high-quality management system including implementation of the latest HIV technologies and algorithms along with human resources and policies are required to minimize the impact of false positive diagnoses, especially in the era of universal screening and 'test and treat' recommendations.

The cost of antiretroviral drug resistance in HIV-positive patients.

INTRODUCTION: Antiretroviral (ARV) drug resistance limits treatment choices, often necessitating the selection of drugs with less desirable pill burdens, toxicity profiles, drug interactions and dosing schedules, and may increase cost. We examine the impact of resistance on the cost of HIV care. METHODS: All adult HIV-positive individuals newly referred for HIV care from 1 January 2007 to 1 January 2011 and followed until 31 December 2011 at the Southern Alberta Clinic, Calgary, AB, Canada, were included. We determined the cost of all ARV drugs, and HIV-related outpatient and inpatient care, reported as mean per patient per month (PPPM) costs in 2011 Canadian dollars (CDN). RESULTS: Overall, 78% of patients received genotypic antiretroviral resistance testing (GART); 57% among ARV-naive patients, 21% after suspected viral failure, and 20% during a treatment interruption. Resistance was detected in 6%, 49% and 21% of all tests respectively. The total mean PPPM cost for patients with GART was CDN 1,179. Patients with primary resistance had mean total PPPM costs of CDN 956. Patients with no resistance had mean PPPM costs of CDN 1,058, by contrast with the CDN 1,291 costs of patients with secondary/acquired resistance. Mean costs for one, two or three ARV class resistance was CDN 1,278, 1,337 and 1,801, respectively. Mean PPPM costs increased by 31% from CDN 1,068 to 1,396, respectively, before and after a positive resistance test. CONCLUSIONS: Transmission of resistant virus as well as emergence of resistance during ARV therapy leads to increased costs. Mean costs increased by number of resistant classes. Routine GART and optimizing ARV regimens to avoid resistance might minimize the long-term costs of HIV care.

Increasing HIV subtype diversity and its clinical implications in a sentinel North American population.

BACKGROUND: HIV-1 is a highly diverse virus; subtypes may exhibit differences in rates of transmission, disease progression, neurotoxicity, antiretroviral treatment failure profiles and accuracy of viral load measurements. To date, the HIV epidemic in Canada and the rest of the developed world has been largely due to subtype B; however, shifts in subtype epidemiology could have significant implications. OBJECTIVE: To determine whether there has been an increase in HIV subtype diversity in southern Alberta, Canada. METHODS: All 2358 patients receiving any HIV care between December 31, 2001 and December 31, 2010 were included in a retrospective analysis of subtype prevalence and incidence. In an indexed analysis, subtype trends from 1994 to 2010 were also evaluated. RESULTS: Between 2001 and 2010, the prevalence of non-B HIV subtypes in patients with a known subtype increased from 7% to 24%. In 2010, the most prevalent non-B subtypes were C (65%), A (11%), CRF02_AG (9.7%), CRF01_AE (4.9%), D (3.9%), G (2.9%) and CRF06_cpx (1.5%). In the indexed analysis, there was an overall proportional increase in non-B subtypes of 2.3% per year. The year-over-year increase in the prevalence of patients infected with a nonsubtype B virus increased from 13% from 1995 to 2002 to 27% from 2003 to 2010 (P=0.01). Incident non-B subtype cases increased from 9.6% to 32.4% over these time periods. CONCLUSIONS: This recent and dramatic shift in HIV strain diversity in Canada is unprecedented and may have important public health, research and clinical consequences.

HISTORIQUE: Le VIH-1 est un virus très hétérogène, dont les sous-types peuvent différer sur le plan du taux de transmission, de l'évolution de la maladie, de la neurotoxicité, des profils d'échec de traitement antirétroviral et de la précision des mesures de la charge virale. Jusqu'à présent, l'épidémie de VIH au Canada et dans le reste du monde industrialisé est en grande partie attribuable au sous-type B, mais des changements dans l'épidémiologie des sous-types pourraient avoir des conséquences considérables. OBJECTIF: Déterminer si la diversité des sous-types de VIH a augmenté dans le sud de l'Alberta, au Canada. MÉTHODOLOGIE: Les 2 358 patients qui avaient reçu des soins du VIH entre le 31 décembre 2001 et le 31 décembre 2010 ont participé à une étude rétrospective de la prévalence et de l'incidence des sous-types. Dans une analyse indexée, les tendances de sous-types ont également été évaluées entre 1994 et 2010. RÉSULTATS: Entre 2001 et 2010, la prévalence des sous-types de VIH non-B chez les patients dont le sous-type est connu est passée de 7 % à 24 %. En 2010, les sous-types non-B les plus prévalents étaient les sous-types C (65 %), A (11 %), CRF02_AG (9,7 %), CRF01_AE (4,9 %), D (3,9 %), G (2,9 %) et CRF06_cpx (1,5 %). Dans l'analyse indexée, on constatait une augmentation proportionnelle globale des sous-types non-B de 2,3 % par année. L'augmentation de la prévalence de patients infectés par un virus de sous-type non-B a augmenté d'une année à l'autre, passant de 13 % de 1995 à 2002 à 27 % de 2003 à 2010 (P=0,01). Les nouveaux cas de sous-types non-B sont passés de 9,6 % à 32,4 % pendant ces périodes. CONCLUSIONS: Ces changements récents et marqués de la diver-sité des souches de VIH au Canada sont sans précédent et pourraient avoir des conséquences importantes en matière de santé publique, de recherche et de clinique.

Comparison of the RealTime HIV-1, COBAS TaqMan 48 v1.0, Easy Q v1.2, and Versant v3.0 assays for determination of HIV-1 viral loads in a cohort of Canadian patients with diverse HIV subtype infections.

HIV clinics in Canada provide care to an increasing number of patients born outside of Canada with HIV-1 non-B subtype infections. Because the Easy Q HIV-1 v1.2 assay (EQ; bioMérieux) failed to detect some non-B subtype infections, a multiassay HIV-1 viral load (VL) study was conducted with patients with diverse HIV subtype infections. Patients were enrolled from the Southern Alberta HIV Clinic (SAC), Calgary, Alberta, Canada (n = 349) and the McGill HIV Clinic (MHC), Montreal, Quebec, Canada (n = 20) and had four or five tubes of blood drawn for testing by EQ and three other commercial HIV VL assays: (i) the Versant 3.0 HIV-1 test, with the Versant 440 instrument (branched DNA [bDNA]; Siemens), (ii) the RealTime HIV-1 test, with the m2000rt instrument (m2000rt; Abbott Molecular Diagnostics), and (iii) the COBAS AmpliPrep TaqMan HIV-1 48 test (CAP-CTM; Roche Molecular Diagnostics). Blood was processed according to the individual manufacturer's requirements and stored frozen at -86°C. The HIV subtype was known for patients who had undergone HIV genotypic resistance testing (Virco, Belgium). Data analyses were done using standard statistical methods within Stata 9.0 (StataCorp, College Station, TX). A total of 371 samples were tested on 369 patients, of whom 291 (81%) had a Virco genotype result of B (195; 53%) or non-B (96; 26%) subtypes A to D and F to K, as well as circulating recombinant forms (CRFs) (i.e., CRF01_AE and CRF02_AG). Most (58/78; 74%) patients of unknown subtype were recent African emigrants who likely have non-subtype B infection. Overall bias was small in pairwise Bland-Altman plots, but the limits of agreement between assays were wide. Discordant viral load results occurred for 98 samples and were due to missing values, false negatives, and significant underquantification that varied by HIV subtype. Results were obtained for all 371 samples with m2000rt, but for only 357 (97%) with CAP-CTM, 338 (92%) with EQ, and 276 (75%) with bDNA due to errors/equipment failures. False-negative results (nondetection of viral RNA versus other assay results) occurred for all platforms, as follows: for m2000rt, 8 (2%) [B(4) and non-B(4) subtypes], CAP-CTM, 9 (2.5%) [B(6) and non-B(3) subtypes]; EQ, 20 (6%) [B(7) and non-B(13) subtypes]; bDNA, 5 (2%) [B(1) and C(4)]. EQ and bDNA had the highest rates of underquantification by ≥ 1.0 log(10) copies/ml, mainly for HIV non-B subtypes. Performance significantly varied between HIV VL platforms according to subtype. HIV viral diversity in the population being tested must be considered in selection of the viral load platform.

Short communication: identification of a novel HIV type 1 subtype H/J recombinant in Canada with discordant HIV viral load (RNA) values in three different commercial assays.

The presence of HIV-1 non-B subtypes is increasing worldwide. This poses challenges to commercial diagnostic and viral load (RNA) monitoring tests that are predominantly based on HIV-1 subtype B strains. Based on phylogenetic analysis of the gag, pol, and env gene regions, we describe the first HIV-1 H/J recombinant in Canada that presented divergent viral load values. DNA sequence analysis of the gag gene region further revealed that genetic diversity between this H/J recombinant and the primers and probes used in the bio-Merieux Nuclisens HIV-1 QT (Nuclisens) and Roche Amplicor Monitor HIV-1, v1.5 (Monitor) viral RNA assays can erroneously lead to undetectable viral load values. This observation appears to be more problematic in the Nuclisens assay. In light of increasing genetic diversity in HIV worldwide we recommend that DNA sequencing of HIV, especially in the gag gene region targeted by primers and probes used in molecular diagnostic and viral load tests, be incorporated into clinical monitoring practices.

Evidence for host-driven selection of the HIV type 1 vpr gene in vivo during HIV disease progression in a transfusion-acquired cohort.

An epidemiologically linked HIV-1-infected cohort, in which a nonprogressor donor infected two recipients who progressed to AIDS, was examined. Sequence analysis, over time, of HIV-1 vpr gene quasispecies from uncultured peripheral blood cells revealed an insertion of arginine at position 90 altering a highly conserved C-terminal motif, believed to play a role in Vpr nuclear targeting. Full genome analysis from each patient showed no gene defects in other gene regions, implying that the mutational selection was unique to the vpr gene. A detailed analysis of the vpr quasispecies showed very little amino acid diversity in the nonprogressing donor, whereas, following viral transmission, the amino acid diversity increased dramatically over time in tandem with disease progression in the two recipients. Although the R insertion at position 90 was present in all three individuals, the variable degree of additional amino acid changes over time may have influenced HIV disease in the nonprogressor donor and the two progressing recipients. These data provide the first evidence in favor of vpr gene evolution over time, which was host-driven. The status of the nonprogressing donor was consistent with a highly protective B-57 HLA type, which was absent in the two progressing recipients, implying a role for host HLA type and other immunologic selective pressures in vpr gene selection in vivo.

Role of viral evolutionary rate in HIV-1 disease progression in a linked cohort.

BACKGROUND: The actual relationship between viral variability and HIV disease progression and/or non-progression can only be extrapolated through epidemiologically-linked HIV-infected cohorts. The rarity of such cohorts accents their existence as invaluable human models for a clear understanding of molecular factors that may contribute to the various rates of HIV disease. We present here a cohort of three patients with the source termed donor A--a non-progressor and two recipients called B and C. Both recipients gradually progressed to HIV disease and patient C has died of AIDS recently. By conducting 15 near full-length genome (8.7 kb) analysis from longitudinally derived patient PBMC samples enabled us to investigate the extent of molecular factors, which govern HIV disease progression. RESULTS: Four time points were successfully amplified for patient A, 4 for patient B and 7 from patient C. Using phylogenetic analysis our data confirms the epidemiological-linkage and transmission of HIV-1 from a non-progressor to two recipients. Following transmission the two recipients gradually progressed to AIDS and one died of AIDS. Viral divergence, selective pressures, recombination, and evolutionary rates of HIV-1 in each member of the cohort were investigated over time. Genetic recombination and selective pressure was evident in the entire cohort. However, there was a striking correlation between evolutionary rate and disease progression. CONCLUSION: Non-progressing individuals have the potential to transmit pathogenic variants, which in other host can lead to faster HIV disease progression. This was evident from our study and the accelerated disease progression in the recipient members of he cohort correlated with faster evolutionary rate of HIV-1, which is a unique aspect of this study.