We have reached single-visit testing, diagnosis, and treatment for hepatitis C infection, now what?

INTRODUCTION: Progress toward hepatitis C virus (HCV) elimination is impeded by low testing and treatment due to the current diagnostic pathway requiring multiple visits leading to loss to follow-up. Point-of-care testing technologies capable of detecting current HCV infection in one hour are a 'game-changer.' These tests enable diagnosis and treatment in a single visit, overcoming the barrier of multiple visits that frequently leads to loss to follow-up. Combining point-of-care HCV antibody and RNA tests should improve cost-effectiveness, patient/provider acceptability, and testing efficiency. However, implementing HCV point-of-care testing programs at scale requires multiple considerations. AREAS COVERED: This commentary explores the need for point-of-care HCV tests, diagnostic strategies to improve HCV testing, key considerations for implementing point-of-care HCV testing programs, and remaining challenges for point-of-care testing (including operator training, quality management, connectivity and reporting systems, regulatory approval processes, and the need for more efficient tests). EXPERT OPINION: It is exciting that single-visit testing, diagnosis, and treatment for HCV infection have been achieved. Innovations afforded through COVID-19 should facilitate the accelerated development of low-cost, rapid, and accurate tests to improve HCV testing. The next challenge will be to address barriers and facilitators for implementing point-of-care testing to deliver them at scale.

Testing, diagnosis, and treatment following the implementation of a program to provide dried blood spot testing for HIV and hepatitis C infections: the NSW DBS Pilot.

BACKGROUND: Dried blood spot (DBS) testing provides an alternative to phlebotomy and addresses barriers to accessing healthcare experienced by some key populations. Large-scale evaluations of DBS testing programs are needed to understand their feasibility. This study evaluated the implementation of a state-wide DBS HIV and hepatitis C virus (HCV) testing pilot. METHODS: The New South Wales (NSW) DBS Pilot is an interventional cohort study of people testing for HIV antibody and/or HCV RNA from DBS samples in NSW, Australia. Participants at risk of HIV/HCV participated in testing via: 1) self-registration online with a DBS collection kit delivered and returned by conventional postal service; or 2) assisted DBS sample collection at 36 community health sites (including drug treatment and harm-minimisation services) and prisons. Participants received results by text (HIV antibody/ HCV RNA not detected) or a healthcare provider (HIV antibody/ HCV RNA detected). The RE-AIM framework was used to evaluate reach, effectiveness, adoption, and implementation. RESULTS: Reach: Between November 2016 and December 2020, 7,392 individuals were tested for HIV and/or HCV (21% self-registration, 34% assisted in community, and 45% assisted in prison). EFFECTIVENESS: Of 6,922 people tested for HIV (19% men who have sex with men, 13% living outside major cities, 21% born outside Australia), 51% (3,521/6,922) had no HIV test in the past two years, 0.1% (10/6,922) were newly diagnosed with HIV, and 80% (8/10) initiated HIV treatment within six months. Of 5,960 people tested for HCV (24% women, 35% Aboriginal and/or Torres Strait Islander, 55% recently injected drugs), 15% had detectable HCV RNA (878/5,960), and 45% (393/878) initiated treatment within six months. Adoption: By the end of 2020, DBS via assisted registration was available at 36 community sites and 21 prisons. IMPLEMENTATION: 90% of DBS cards arriving at the laboratory had the three full spots required for testing; the proportion was higher in assisted (94%) compared to online (76%) registration. CONCLUSIONS: This study demonstrated the feasibility of DBS testing for HIV and HCV in key populations including Aboriginal and Torres Strait Islander peoples, men who have sex with men, people who inject drugs, and demonstrated the utility of DBS in the prison setting.

Hepatitis C Treatment Uptake Following Dried Blood Spot Testing for Hepatitis C RNA in New South Wales, Australia: The NSW DBS Pilot Study.

Background: Dried blood spot (DBS) testing for hepatitis C virus (HCV) RNA provides a sampling option that avoids venepuncture and can be carried out in a nonclinical setting. Large-scale evaluations are needed to understand how DBS testing can reduce HCV burden. This study estimated prevalence of, and factors associated with, HCV RNA and treatment initiation among people enrolled in a state-wide pilot of people testing in the NSW DBS Pilot in New South Wales, Australia. Methods: People at risk of HIV/HCV could participate via (1) self-registration online with a DBS collection kit delivered and returned by conventional postal service; or (2) assisted DBS sample collection at a community site or prison. Logistic regression was used to identify factors associated with detectable HCV RNA and treatment initiation within 6 months of testing. Results: Between September 2017 and December 2020, 5960 people were tested for HCV (76% men, 35% Aboriginal and/or Torres Strait Islander, 55% recently injected drugs): 21% online self-registration, 34% assisted registration in the community, 45% assisted registration in prison. Fifteen percent had detectable HCV RNA (878/5960). Overall, 44% (n = 386/878) of people with current HCV initiated treatment within 6 months (13% online self-registration, 27% assisted registration in the community, 61% assisted registration in prison). Testing in prison compared with the community (adjusted odds ratio [aOR], 4.28; 95% CI, 3.04-6.03) was associated with increased odds of treatment initiation. Being a woman compared with a man (aOR, 0.68; 95% CI, 0.47-0.97) was associated with reduced treatment initiation. Conclusions: The NSW DBS Pilot demonstrates the feasibility of using DBS to promote HCV testing and treatment in community and prison settings.

High titre neutralizing antibodies in response to SARS-CoV-2 infection require RBD-specific CD4 T cells that include proliferative memory cells.

Background: Long-term immunity to SARS-CoV-2 infection, including neutralizing antibodies and T cell-mediated immunity, is required in a very large majority of the population in order to reduce ongoing disease burden. Methods: We have investigated the association between memory CD4 and CD8 T cells and levels of neutralizing antibodies in convalescent COVID-19 subjects. Findings: Higher titres of convalescent neutralizing antibodies were associated with significantly higher levels of RBD-specific CD4 T cells, including specific memory cells that proliferated vigorously in vitro. Conversely, up to half of convalescent individuals had low neutralizing antibody titres together with a lack of receptor binding domain (RBD)-specific memory CD4 T cells. These low antibody subjects had other, non-RBD, spike-specific CD4 T cells, but with more of an inhibitory Foxp3+ and CTLA-4+ cell phenotype, in contrast to the effector T-bet+, cytotoxic granzymes+ and perforin+ cells seen in RBD-specific memory CD4 T cells from high antibody subjects. Single cell transcriptomics of antigen-specific CD4+ T cells from high antibody subjects similarly revealed heterogenous RBD-specific CD4+ T cells that comprised central memory, transitional memory and Tregs, as well as cytotoxic clusters containing diverse TCR repertoires, in individuals with high antibody levels. However, vaccination of low antibody convalescent individuals led to a slight but significant improvement in RBD-specific memory CD4 T cells and increased neutralizing antibody titres. Interpretation: Our results suggest that targeting CD4 T cell epitopes proximal to and within the RBD-region should be prioritized in booster vaccines.

Evaluation of serological assays for SARS-CoV-2 antibody testing from dried blood spots collected from cohorts with prior SARS-CoV-2 infection.

Background: Dried blood spot (DBS) specimens are a useful serosurveillance tool particularly in hard-to-reach populations but their application for detecting SARS-CoV-2 infection is poorly characterised. Objectives: To compare detection of naturally acquired SARS-CoV-2 antibodies in paired DBS and serum specimens using commercially available serological immunoassays. Study Design: Specimens were collected through St Vincent's Hospital observational post COVID-19 cohort study (ADAPT). Laboratory spotted DBS from venepuncture were initially tested on seven assays, a DBS validation completed on three with clinically collected fingerstick DBSs tested on one. Results: Sensitivity for Euroimmun nucleocapsid (NCP) IgG ELISA from laboratory spotted DBS (n=145), Euroimmun spike, IgG ELISA from laboratory spotted DBS (n=161), and Binding Site total antibody ELISA from clinically collected fingerstick DBS (n=391) was 100% (95% CI: 95.8-100%), 100% (95% CI: 95.8-100%) and 92.9% (95% CI: 89.5-95.5%), respectively. Specificity was 66.2% (95% CI: 53.6-77.0%), 96% (95% CI: 88.7-99.1%) and 98.8% (95% CI: 93.3-99.9%), respectively. All three assays' results displayed a strong positive correlation between DBS compared to paired serum. Conclusions: The Binding Site™ spike total antibody and Euroimmun™ spike IgG ELISAs provided good analytical performance, demonstrating that DBS specimens could facilitate specimen collection in the epidemiological surveillance of SARS-CoV-2 infection. This is highly applicable in populations and settings where venepuncture is problematic (including community based regional/remote settings, nursing homes, prisons, and schools).

A national survey integrating clinical, laboratory, and WASH data to determine the typology of trachoma in Nauru.

BACKGROUND: The epidemiology of trachoma in several Pacific Islands differs from other endemic settings, in that there is a high prevalence of clinical signs of trachoma, particularly trachomatous inflammation-follicular (TF), but few cases of trichiasis and limited evidence of ocular chlamydial infection. This so-called "Pacific enigma" has led to uncertainty regarding the appropriate public health response. In 2019 alongside Nauru's national trachoma population survey, we performed bacteriological and serological assessments of children to better understand the typology of trachoma and to determine whether there is a need for trachoma interventions. METHODS: We used two-stage cluster sampling, examining residents aged ≥1 year and collecting household-level water, sanitation, and hygiene (WASH) variables. Children aged 1-9 years provided conjunctival swabs and finger-prick dried blood spots to investigate the presence of Chlamydia trachomatis nucleic acid and anti-Pgp3 antibodies, respectively. PRINCIPAL FINDINGS: In 818 participants aged 1-9 years, the age-adjusted TF prevalence was 21.8% (95% CI 15.2-26.2%); ocular C. trachomatis prevalence was 34.5% (95% CI 30.6-38.9), and anti-Pgp3 antibody prevalence was 32.1% (95% CI 28.4%-36.3%). The age- and gender-adjusted prevalence of trichiasis in ≥15-year-olds was 0.3% (95% CI 0.00-0.85), but no individual with trichiasis had trachomatous scarring (TS). Multivariable analysis showed an association between age and both TF (OR per year of age 1.3 [95% CI 1.2-1.4]) and anti-Pgp3 positivity (OR 1.2 [95% CI 1.2-1.3]). There were high rates of access to water and sanitation and no WASH variable was associated with the presence of TF. CONCLUSIONS: TF, nucleic acid, and age-specific antibody prevalence collectively indicate that high levels of C. trachomatis transmission among children present a high risk of ocular damage due to trachoma. The absence of trichiasis with trachomatous scarring suggest a relatively recent increase in transmission intensity.

Diagnostic Accuracy of Assays Using Point-of-Care Testing or Dried Blood Spot Samples for the Determination of Hepatitis C Virus RNA: A Systematic Review.

BACKGROUND: Finger-stick point-of-care and dried blood spot (DBS) hepatitis C virus (HCV) RNA testing increases testing uptake and linkage to care. This systematic review evaluated the diagnostic accuracy of point-of-care testing and DBS to detect HCV RNA. METHODS: Bibliographic databases and conference presentations were searched for eligible studies. Meta-analysis was used to pool estimates. RESULTS: Of 359 articles identified, 43 studies were eligible and included. When comparing the Xpert HCV Viral Load Fingerstick assay to venous blood samples (7 studies with 987 samples), the sensitivity and specificity for HCV RNA detection was 99% (95% confidence interval [CI], 97%-99%) and 99% (95% CI, 94%-100%) and for HCV RNA quantification was 100% (95% CI, 93%-100%) and 100% (95% CI, 94%-100%). The proportion of invalid results following Xpert HCV Viral Load Fingerstick testing was 6% (95% CI, 3%-11%). When comparing DBS to venous blood samples (28 studies with 3988 samples) the sensitivity and specificity for HCV RNA detection was 97% (95% CI, 95%-98%) and 100% (95% CI, 98%-100%) and for HCV RNA quantification was 98% (95% CI, 96%-99%) and 100% (95% CI, 95%-100%). CONCLUSIONS: Excellent diagnostic accuracy was observed across assays for detection of HCV RNA from finger-stick and DBS samples. The proportion of invalid results following Xpert HCV Viral Load Fingerstick testing highlights the importance of operator training and quality assurance programs.

A multi-center study comparing the analytical sensitivity and clinical concordance of three HIV-1 viral load assays.

BACKGROUND: HIV-1 viral load assays are essential tools for clinical management of people living with HIV-1. OBJECTIVES AND STUDY DESIGN: We evaluated concordance between three assays: the cobas® HIV-1 test for use on the cobas® 6800 and cobas® 8800 systems (cobas HIV-1); the COBAS® TaqMan® HIV-1 Test, v2.0 for use with the High Pure System and the COBAS® AmpliPrep/COBAS® TaqMan® HIV-1 test, v2.0. Analytical sensitivity, precision and accuracy of all three methods were assessed using the WHO 2nd International Standard for HIV-1, with concentrations from 5 to 1000 copies/mL. Accuracy and concordance were evaluated using 212 clinical specimens. Overall percent agreement (OPA) was determined using three different thresholds used as medical decision points. RESULTS: The limit of detection was below 20 copies/mL for each assay. The hit rate for each assay was 100 % for concentrations ≥ 50 copies/mL. Only the cobas HIV-1 test generated quantifiable data for all replicates at 50 copies/mL. Between 50 and 400 copies/mL, results for all assays were accurate within 0.09 log10 copies/mL, with standard deviation less than 0.14 log10 copies/mL. The mean difference between paired results in clinical specimens ranged from -0.050 to 0.107 log10 copies/mL across all assay comparisons. The OPA between pairs of assays ranged from 94.8 to 98.1% at the 50 copies/mL cutoff, and improved to a range of 97.6-99.0% at the 200 copies/mL cutoff. At the 1000 copies/mL cutoff, OPA between assays was 98.5-99.0%. CONCLUSIONS: The cobas HIV-1 assay is highly sensitive, accurate and suitable for use in clinical practice.

SARS-CoV-2 neutralizing antibodies: Longevity, breadth, and evasion by emerging viral variants.

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) antibody neutralization response and its evasion by emerging viral variants and variant of concern (VOC) are unknown, but critical to understand reinfection risk and breakthrough infection following vaccination. Antibody immunoreactivity against SARS-CoV-2 antigens and Spike variants, inhibition of Spike-driven virus-cell fusion, and infectious SARS-CoV-2 neutralization were characterized in 807 serial samples from 233 reverse transcription polymerase chain reaction (RT-PCR)-confirmed Coronavirus Disease 2019 (COVID-19) individuals with detailed demographics and followed up to 7 months. A broad and sustained polyantigenic immunoreactivity against SARS-CoV-2 Spike, Membrane, and Nucleocapsid proteins, along with high viral neutralization, was associated with COVID-19 severity. A subgroup of "high responders" maintained high neutralizing responses over time, representing ideal convalescent plasma donors. Antibodies generated against SARS-CoV-2 during the first COVID-19 wave had reduced immunoreactivity and neutralization potency to emerging Spike variants and VOC. Accurate monitoring of SARS-CoV-2 antibody responses would be essential for selection of optimal responders and vaccine monitoring and design.

HIV-1 viral blips are associated with repeated and increasingly high levels of cell-associated HIV-1 RNA transcriptional activity.

OBJECTIVE: Some HIV+ patients, virally suppressed on ART, show occasional 'blips' of detectable HIV-1 plasma RNA. We used a new highly sensitive assay of cell-associated HIV-1 RNA to measure transcriptional activity in PBMCs and production of infectious virus from the viral reservoir, in patients with and without 'blips'. DESIGN/METHODS: RNA and DNA extracted from cells in 6 ml of peripheral blood, from suppressed patients with one to two 'blip' episodes over the past 2 years of ART (n = 55), or no 'blips' (n = 52), were assayed for HIV-1 RNA transcripts and proviral DNA targeting the highly conserved 'R' region of the LTR. Follow-up samples were also collected. Purified CD4+ T cells were cultured with anti-CD3/CD28/CD2 T-cell activator to amplify transcription and measure replication competent virus. RESULTS: HIV-1 RNA transcripts ranged from 1.3 to 5415 copies/106 white blood cells. 'Blip' patients had significantly higher levels vs. without blips (median 192 vs. 49; P = 0.0007), which correlated with: higher levels of inducible transcripts after activation in vitro, sustained higher HIV-1 transcription levels in follow-up samples along with increasing HIV-1 DNA in some, and production of replication-competent HIV-1. CONCLUSION: Viral 'blips' are significant reflecting higher transcriptional activity from the reservoir and contribute to the reservoir over time. This sensitive assay can be used in monitoring the size and activity of the HIV-1 reservoir and will be useful in HIV-1 cure strategies.

Evolution of HIV-1 Surveillance Drug Resistance Mutations Over 10 Years in New South Wales, Australia.

New South Wales has the greatest burden of HIV in Australia, with 2012 and 2013 recording the highest rates of new diagnoses in 20 years. Concurrently, there has been significant changes in antiretroviral treatments and testing paradigms. We compiled a statewide resistance database to characterize changes in HIV-1 resistance mutations over time. Genotypic antiretroviral resistance testing (GART) was performed on request at three reference laboratories using commercial and in-house methods. In total, 7629 HIV-1 polymerase sequences obtained from GART from 2004 to 2013 were retrospectively collated, reformatted, de-identified, and analyzed using Stanford HIVdb program 7.0 and the 2009 World Health Organization (WHO) surveillance drug resistance mutations (SDRMs). Analyses were performed on subgroups of known treatment naives, treatment experienced, and seroconverters. There has been a decrease in overall rates of prevalent drug resistance mutations from 57.8% in 2004 to 21% in 2013. Dual and triple class resistance mutations have decreased from 32.7% in 2004 to 5.8% in 2013 and 16.4% to 1.2%, respectively. In treatment-naive individuals (n = 450), the frequency of protease inhibitor (PI) mutations remains low at 2.7%. In seroconverters, rates of transmitted drug resistance (TDR) are 6.6%, 3%, 3%, and 1.5% for overall, PI, non-nucleoside reverse transcription inhibitor (NNRTI), and NRTI, respectively. In treatment experienced, rates remain stable with 36.0%, 18.9%, 29.1%, and 6.4% for overall, NNRTI, NRTI, and PI mutations. The most common mutations in treatment experienced occurred at position M184, T215 (NRTI); K103 (NNRTI); I54 (PI). Apparent decreases in prevalent SDRMs can be attributed to changes in GART testing indications over time. In treatment-naive and -experienced subgroups, rates have been stable with low rates of TDR in seroconverters.

Evaluation of the Aptima HCV Quant Dx Assay for Hepatitis C Virus RNA Detection from Fingerstick Capillary Dried Blood Spot and Venepuncture-Collected Samples.

BACKGROUND: Simplified diagnostic strategies are needed increase hepatitis C virus (HCV) testing to determine active infection and link people into treatment. Collection methods such as dried blood spots (DBS) have advantages over standard phlebotomy, especially within marginalized populations. METHODS: We evaluated the diagnostic performance of the Aptima HCV Quant assay for the quantification and detection of HCV RNA from paired DBS and venepuncture samples. Specimens were collected from participants enrolled in an Australian observational study. We compared HCV RNA detection from DBS against venepuncture samples (gold standard). RESULTS: One hundred sixty-four participants had paired samples and HCV RNA was detected in 45 (27% [95% confidence interval, 21%-35%]) by the Aptima assay in venepuncture samples. Sensitivity of the Aptima assay for HCV RNA quantification from DBS (≥10 IU/mL in plasma) was 100% and specificity was 100%. Sensitivity for HCV RNA detection from DBS was 95.6% and specificity was 94.1%. A small bias in plasma over DBS was observed with good agreement (R2 = 0.96). CONCLUSIONS: The Aptima HCV Quant assay detects active infection from DBS samples with acceptable diagnostic performance and is clinically comparable to plasma. These data will strengthen the case for the registration of a DBS kit insert claim, enabling future clinical utility.

Expression and In Vivo Characterization of the Antimicrobial Peptide Oncocin and Variants Binding to Ribosomes.

Peptides have important biomedical applications, but poor correlation between in vitro and in vivo activities can limit their development for clinical use. The ability to generate peptides and monitor their expression with new mass spectrometric methods and biological activities in vivo would be an advantage for the discovery and improvement of peptide-based drugs. In this study, a plasmid-based system was used to express the ribosome-targeting peptide oncocin (19 amino acids, VDKPPYLPRPRPPRRIYNR) and to determine its direct antibacterial effects on Escherichia coli. Previous biochemical and structure studies showed that oncocin targets the bacterial ribosome. The oncocin peptide generated in vivo strongly inhibits bacterial growth. In vivo dimethyl sulfate footprinting of oncocin on the rRNA gives results that are consistent with those of in vitro studies but reveals additional binding interactions with E. coli ribosomes. Furthermore, expression of truncated or mutated peptides reveals which amino acids are important for antimicrobial activity. Overall, the in vivo peptide expression system can be used to investigate biological activities and interactions of peptides with their targets within the cellular environment and to separate contributions of the sequence to cellular transport. This strategy has future applications for improving the effectiveness of existing peptides and developing new peptide-based drugs.

Estimating the Consensus hepatitis C Cascade of Care among people who inject drugs in Australia: Pre and post availability of direct acting antiviral therapy.

Background Monitoring the hepatitis C virus (HCV) cascade of care (CoC) among people who inject drugs (PWID) is an essential component of the response to World Health Organisation's (WHO) hepatitis elimination goals. This study aimed to estimate the Consensus hepatitis C CoC among PWID using data collected in Australia prior to and after the introduction of unrestricted direct-acting antiviral (DAA) therapy in March 2016. Methods The Australian Needle Syringe Program Survey is a cross-sectional bio-behavioural surveillance system that recruits >2000 PWID annually. Using data from 2015 and 2019, HCV antibody and ribonucleic acid (RNA) test results from dried blood spots were combined with self-reported data on HCV diagnostic testing and treatment to project HCV Consensus CoC indicators at a population-level among Australian PWID. Results Among an estimated 75,000 people who inject drugs on a regular basis in Australia, the number with active HCV infection declined from 32,619 (44%) in October 2015 to 12,679 (17%) in October 2019. The majority (78% in 2015 and 2019) of PWID reported HCV diagnosis, while the proportion of those diagnosed who were treated increased from 3% in 2015 to 47% in 2019. Among those treated, the proportion who were HCV RNA negative and assumed to have been successfully treated (cured), increased from 27% in 2015 to 88% in 2019. Conclusion This study demonstrates remarkable HCV CoC progress among PWID in Australia following availability of DAA therapy. There was a substantial increase in the proportion of HCV diagnosed PWID who initiated treatment and were cured, while the number of PWID with active HCV infection more than halved over a 3.5 year period. Estimates of the Consensus hepatitis C CoC among PWID is required to monitor progress toward WHO HCV elimination goals.

Time to Detection of Hepatitis C Virus Infection With the Xpert HCV Viral Load Fingerstick Point-of-Care Assay: Facilitating a More Rapid Time to Diagnosis.

BACKGROUND: Xpert HCV Viral Load Fingerstick assay (Xpert HCV VL FS) is a point-of-care test quantifying HCV RNA in <1 hour, enabling same-visit diagnosis and treatment. METHODS: This study evaluated time to HCV RNA detection using the Xpert HCV VL FS assay. Fingerstick whole-blood samples were collected from participants in an observational cohort in Australia. RESULTS: In May 2018-2019, 1468 participants were enrolled, 1426 had Xpert HCV VL FS testing performed, and 1386 had a valid result. HCV RNA was detected in 23% (325/1386). Among people with undetectable HCV RNA (n = 1061), median time to result was 57 minutes. Among people with detectable HCV RNA (n = 325), median time to HCV RNA detection was 32 minutes and 80% (261/325) had a detectable HCV RNA result in ≤40 minutes. Median time to HCV RNA detection was dependent on HCV RNA level. CONCLUSIONS: A quicker HCV diagnosis could be achieved by monitoring the time when HCV RNA is first detected with the Xpert HCV VL FS test, rather than HCV RNA quantification, although the current platform does not allow for this. These findings could facilitate new strategies to reduce waiting times for an HCV diagnosis and improve linkage to treatment.

Evaluation of a hepatitis C virus core antigen assay from venepuncture and dried blood spot collected samples: A cohort study.

The global scale-up of hepatitis C virus (HCV) diagnosis requires simplified and affordable HCV diagnostic pathways. This study evaluated the sensitivity and specificity of the HCV Architect core antigen (HCVcAg) assay for detection of active HCV infection in plasma and capillary whole blood dried blood spots (DBS) compared with HCV RNA testing in plasma (Abbott RealTime HCV Viral Load). Samples were collected from participants in an observational cohort enrolled at three sites in Australia (two-drug treatment and alcohol clinics and one homelessness service). Of 205 participants, 200 had results across all samples and assay types and 186 were included in this analysis (14 participants receiving HCV therapy were excluded). HCV RNA was detected in 29% of participants ([95% CI: 22.6-36.1], 54 of 186). The sensitivity of HCVcAg for detection of active HCV infection in plasma was 98.1% (95% CI: 90-100) and 100% (95% CI: 93-100) when compared to HCV RNA thresholds of ≥12 and ≥1000 IU/mL, respectively. The sensitivity of the HCVcAg assay for detection of active HCV infection in DBS was 90.7% (95% CI: 80-97) and 92.5% (95% CI: 82-98) when compared to HCV RNA thresholds of ≥12 and ≥1000 IU/mL, respectively. The specificity of HCV core antigen for detection of active infection was 100% (95% CI: 97-100) for all samples and RNA thresholds. These data indicate that the detection of HCVcAg is a useful tool for determining active HCV infection; to facilitate enhanced testing, linkage to care and treatment particularly when testing plasma samples are collected by venepuncture.

Possible clearance of transfusion-acquired nef/LTR-deleted attenuated HIV-1 infection by an elite controller with CCR5 Δ32 heterozygous and HLA-B57 genotype.

BACKGROUND: Subject C135 is one of the members of the Sydney Blood Bank Cohort, infected in 1981 through transfusion with attenuated nef/3' long terminal repeat (LTR)-deleted HIV-1, and has maintained undetectable plasma viral load and steady CD4 cell count, in the absence of therapy. Uniquely, C135 combines five factors separately associated with control of viraemia: nef/LTR-deleted HIV-1, HLA-B57, HLA-DR13, heterozygous CCR5 Δ32 genotype and vigorous p24-stimulated peripheral blood mononuclear cell (PBMC) proliferation. Therefore, we studied in detail viral burden and immunological responses in this individual. METHODS: PBMC and gut and lymph node biopsy samples were analysed for proviral HIV-1 DNA by real-time and nested PCRs, and nef/LTR alleles by nested PCR. HIV-specific antibodies were studied by Western blotting, and CD4+ and CD8+ T lymphocyte responses were measured by proliferation and cytokine production in vitro. RESULTS: PBMC samples from 1996, but not since, showed amplification of nef alleles with gross deletions. Infectious HIV-1 was never recovered. Proviral HIV-1 DNA was not detected in recent PBMC or gut or lymph node biopsy samples. C135 has a consistently weak antibody response and a substantial CD4+ T cell proliferative response to a previously described HLA-DR13-restricted epitope of HIV-1 p24 in vitro, which augmented a CD8+ T cell response to an immunodominant HLA-B57-restricted epitope of p24, while his T cells show reduced levels of CCR5. CONCLUSIONS: Subject C135's early PCR and weak antibody results are consistent with limited infection with a poorly replicating nef/LTR-deleted strain of HIV-1. With his HLA-B57-restricted gag-specific CD8 and helper HLA-DR13-restricted CD4 T cell proliferative responses, C135 appears to have cleared his HIV-1 infection 37 years after transfusion.

Rapid HIV testing increases testing frequency among gay and bisexual men: a controlled before-after study.

Background Rapid HIV testing was introduced at 12 clinics in New South Wales (NSW) for routine testing and promoted with social marketing. The effect of the availability of rapid HIV testing on testing frequency among gay and bisexual men (GBM) was evaluated. METHODS: An observational design using patient data from 12 clinics was used. The primary outcome was the mean number of HIV tests in 12 months. The intervention group comprised GBM who had one or more rapid tests from October 2013 to September 2014 and this was compared with two control groups; a concurrent group (no rapid test in the same period) and a historical group (attended between July 2011 and June 2012). Independent sample t-tests were conducted to compare mean number of tests among men in the intervention, concurrent and historical groups. Multivariate logistic regression was used to assess the association between rapid HIV testing and testing frequency. RESULTS: Men in the intervention group (n = 3934) had a mean of 1.8 HIV tests in 12 months, compared with 1.4 in the concurrent group (n = 5063; P < 0.001) and 1.4 in the historical group (n = 5904; P < 0.001); testing frequency was higher among men at increased risk of HIV in the intervention group compared with the other two groups (mean 2.2, 1.6 and 1.5 respectively; P < 0.001). Membership of the intervention group was associated with increased odds of having two or more HIV tests in 12 months (AOR = 2.5, 95%CI 2.2-2.8; P < 0.001) compared with the concurrent group, after controlling for demographic and behavioural factors. CONCLUSION: Introducing and promoting rapid HIV testing in clinics in NSW was associated with increased HIV testing frequency among GBM.