Prevalence and Phenotypic Susceptibility to Doravirine of the HIV-1 Reverse Transcriptase V106I Polymorphism in B and Non-B Subtypes.

BACKGROUND: Limited data are available regarding the susceptibility of the reverse transcriptase V106 polymorphism to doravirine. METHODS: Doravirine susceptibility was measured in site-directed mutants (SDMs) containing V106I, V106A, V106M, and Y188L mutations in subtype B (NL4-3, HXB2) and CRF02_AG background and in recombinant viruses with RT harboring V106I alone derived from 50 people with HIV. RESULTS: HIV-1 B subtype was detected in 1523 of 2705 cases. Prevalence of V106I was 3.2% in B and 2.5% in non-B subtypes, and was higher in subtype F (8.1%) and D (14.3%). Fold-changes (FC) in susceptibility for SDMs were below doravirine biological cutoff (3.0) for V106I, but not for V106A, V106M, and Y188L. Clinically derived viruses tested included 22 B (median FC, 1.2; interquartile range [IQR], 0.9-1.6) and 28 non-B subtypes (median FC, 1.8; IQR, 0.9-3.0). Nine (18%) viruses showed FC values equal or higher than the doravirine biological FC cutoff. CONCLUSIONS: The prevalence of the HIV-1 RT V106I polymorphism in MeditRes HIV consortium remains low, but significantly more prevalent in subtypes D and F. V106I minimally decreased the susceptibility to doravirine in SDMs and most clinical isolates. Reduced susceptibility seems to occur at increased frequency in subtype F1; however, the clinical impact remains to be investigated. CLINICAL TRIALS REGISTRATION: NCT04894357.

Detailed stratified GWAS analysis for severe COVID-19 in four European populations.

Given the highly variable clinical phenotype of Coronavirus disease 2019 (COVID-19), a deeper analysis of the host genetic contribution to severe COVID-19 is important to improve our understanding of underlying disease mechanisms. Here, we describe an extended genome-wide association meta-analysis of a well-characterized cohort of 3255 COVID-19 patients with respiratory failure and 12 488 population controls from Italy, Spain, Norway and Germany/Austria, including stratified analyses based on age, sex and disease severity, as well as targeted analyses of chromosome Y haplotypes, the human leukocyte antigen region and the SARS-CoV-2 peptidome. By inversion imputation, we traced a reported association at 17q21.31 to a ~0.9-Mb inversion polymorphism that creates two highly differentiated haplotypes and characterized the potential effects of the inversion in detail. Our data, together with the 5th release of summary statistics from the COVID-19 Host Genetics Initiative including non-Caucasian individuals, also identified a new locus at 19q13.33, including NAPSA, a gene which is expressed primarily in alveolar cells responsible for gas exchange in the lung.

Multi-center evaluation of the Research Use Only NeuMoDx monkeypox virus (MPXV) fully automated real-time PCR assay.

The mpox outbreak, caused by monkeypox virus (MPXV), accelerated the development of molecular diagnostics. In this study, we detail the evaluation of the Research Use Only (RUO) NeuMoDx MPXV assay by multiple European and US sites. The assay was designed and developed by Qiagen for the NeuMoDx Molecular Systems. Primers and probes were tested for specificity and inclusivity in silico. The analytical sensitivity of the assay was determined by testing dilutions of synthetic and genomic MPXV DNA. A total of 296 clinical samples were tested by three sites; the Johns Hopkins University (US), UZ Gent (Belgium, Europe), and Hospital Universitario San Cecilio (Spain, Europe). The analytical sensitivity of the assay was 50 copies/mL for both clades I and II. The assay showed 100% in silico identity for 80 clade I and 99.98% in silico identity for 5,162 clade II genomes. Clade II primers and probes showed 100% in silico specificity; however, identity of at least one of the two sets of clade I primers and probes with variola, cowpox, camelpox, and vaccinia viruses was noticed. The clinical validation showed sensitivity of 99.21% [95% confidence interval (CI): 95.66-99.98%] and specificity of 96.64% (95% CI: 91.62-99.08%) for lesion swab samples. The NeuMoDx MPXV Test shows acceptable analytical and clinical performance. The assay improves the laboratory's workflow as it consolidates nucleic acid extraction, PCR, data analysis, and interpretation and can be interfaced. The Test Strip can differentiate clades I and II, which has important laboratory safety implications. IMPORTANCE: In this manuscript, we provide detailed in silico analysis and clinical evaluation of the assay using a large cohort of clinical samples across three academic centers in Europe and the United States. Because the assay differentiates MPXV clades I and II, this manuscript is timely due to the current need to rule out the regulated clade I by diagnostic clinical laboratories. In December 2023, and due to first report of cases of sexually transmitted clade I infections in the Democratic Republic of the Congo, when generic assays that do not differentiate the clades are used, samples are considered regulated. The assay meets the need of full automation and has a marked positive impact on the laboratory workflow.

Transmitted Drug Resistance to Integrase-Based First-Line Human Immunodeficiency Virus Antiretroviral Regimens in Mediterranean Europe.

BACKGROUND: We evaluated the prevalence of transmitted drug resistance (TDR) to integrase strand-transfer inhibitors (INSTIs) and nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) and of clinically relevant resistance (CRR) in newly diagnosed people with human immunodeficiency virus (HIV; PWH) naive to antiretroviral therapy (ART) in Europe. METHODS: MeditRes is a consortium that includes ART-naive PWH newly diagnosed in France, Greece, Italy, Portugal, and Spain during 2018-2021. Reverse transcriptase and INSTI sequences were provided by participating centers. To evaluate the prevalence of surveillance drug resistance mutations (SDRM), we used the calibrated population resistance tools from the Stanford HIV website. To evaluate CRR, defined as any resistance level ≥3, we used the Stanford HIV Drug Resistance Database v.9.1 algorithm. RESULTS: We included 2705 PWH, 72% men, median age of 37 years (interquartile range, 30-48); 43.7% were infected by non-B subtypes. The prevalence of INSTI-SDRMs was 0.30% (T66I, T66A, E92Q, E138T, E138K, Y143R, S147G, R263K; all n=1) and the prevalence of NRTI-SDRMs was 5.77% (M184V: 0.85%; M184I: 0.18%; K65R/N: 0.11%; K70E: 0.07%; L74V/I: 0.18%; any thymidine analog mutations: 4.36%). INSTI-CRR was 2.33% (0.15% dolutegravir/bictegravir, 2.29% raltegravir/elvitegravir) and 1.74% to first-line NRTIs (0.89% tenofovir/tenofovir alafenamide, 1.74% abacavir, 1.07% lamivudine/emtricitabine). CONCLUSIONS: We present the most recent data on TDR to integrase-based first-line regimens in Europe. Given the low prevalence of CRR to second-generation integrase inhibitors and to first-line NRTIs during 2018-2021, it is unlikely that newly diagnosed PWH in MeditRes countries would present with baseline resistance to a first-line regimen based on second-generation integrase inhibitors.

Transmitted drug resistance to antiretroviral drugs in Spain during the period 2019-2021.

To evaluate the prevalence of transmitted drug resistance (TDR) to nucleoside and nonnucleoside reverse transcriptase inhibitors (NRTI, NNRTI), protease inhibitors (PI), and integrase strand transfer inhibitors (INSTI) in Spain during the period 2019-2021, as well as to evaluate transmitted clinically relevant resistance (TCRR) to antiretroviral drugs. Reverse transcriptase (RT), protease (Pro), and Integrase (IN) sequences from 1824 PLWH (people living with HIV) were studied. To evaluate TDR we investigated the prevalence of surveillance drug resistance mutations (SDRM). To evaluate TCRR (any resistance level ≥ 3), and for HIV subtyping we used the Stanford v.9.4.1 HIVDB Algorithm and an in-depth phylogenetic analysis. The prevalence of NRTI SDRMs was 3.8% (95% CI, 2.8%-4.6%), 6.1% (95% CI, 5.0%-7.3%) for NNRTI, 0.9% (95% CI, 0.5%-1.4%) for PI, and 0.2% (95% CI, 0.0%-0.9%) for INSTI. The prevalence of TCRR to NRTI was 2.1% (95% CI, 1.5%-2.9%), 11.8% for NNRTI, (95% CI, 10.3%-13.5%), 0.2% (95% CI, 0.1%-0.6%) for PI, and 2.5% (95% CI, 1.5%-4.1%) for INSTI. Most of the patients were infected by subtype B (79.8%), while the majority of non-Bs were CRF02_AG (n = 109, 6%). The prevalence of INSTI and PI resistance in Spain during the period 2019-2021 is low, while NRTI resistance is moderate, and NNRTI resistance is the highest. Our results support the use of integrase inhibitors as first-line treatment in Spain. Our findings highlight the importance of ongoing surveillance of TDR to antiretroviral drugs in PLWH particularly with regard to first-line antiretroviral therapy.

The imperative for quality control programs in Monkeypox virus DNA testing by PCR: CIBERINFEC quality control.

To evaluate molecular assays for Mpox diagnosis available in various clinical microbiology services in Spain through a quality control (QC) approach. A total of 14 centers from across Spain participated in the study. The Reference Laboratory dispatched eight serum samples and eight nucleic acid extracts to each participating center. Some samples were spiked with Mpox or Vaccinia virus to mimic positive samples for Mpox or other orthopox viruses. Participating centers provided information on the results obtained, as well as the laboratory methods used. Among the 14 participating centers seven different commercial assays were employed, with the most commonly used kit being LightMix Modular Orthopox/Monkeypox (Mpox) Virus (Roche®). Of the 12 centers conducting Mpox determinations, concordance ranged from 62.5% (n = 1) to 100% (n = 11) for eluates and from 75.0% (n = 1) to 100% (n = 10) for serum. Among the 10 centers performing Orthopoxvirus determinations, a 100% concordance was observed for eluates, while for serum, concordance ranged from 87.5% (n = 6) to 100% (n = 4). Repeatedly, 6 different centers reported a false negative in serum samples for Orthopoxvirus diagnosis, particularly in a sample with borderline Ct = 39. Conversely, one center, using the TaqMan™ Mpox Virus Microbe Detection Assay (Thermo Fisher), reported false positives in Mpox diagnosis for samples spiked with vaccinia virus due to cross-reactions. We observed a positive correlation of various diagnostic assays for Mpox used by the participating centers with the reference values. Our results highlight the significance of standardization, validation, and ongoing QC in the microbiological diagnosis of infectious diseases, which might be particularly relevant for emerging viruses.

The prevalence of Mycoplasma genitalium (MG) and Trichomonas vaginalis (TV) at testing centers in Belgium, Germany, Spain, and the UK using the cobas TV/MG molecular assay.

Mycoplasma genitalium (MG) and Trichomonas vaginalis (TV) can lead to long-term sequelae in males and females; however, global prevalence data vary between geographical regions, as these sexually transmitted infections are not included in routine screening. The objective of this study was to use the cobas® TV/MG assay to assess the point prevalence of TV and MG in specimens from men and women over a broad European geographical area. Urine, vaginal, endocervical, and rectal samples were collected from patients aged ≥ 18 years receiving Chlamydia trachomatis (CT) and/or Neisseria gonorrhoeae (NG) screening as per local standard of care at sites in Belgium, Germany, Spain, and the UK (Wales). Remnant samples were assessed using the cobas TV/MG assay. Analysis of 2795 samples showed that MG prevalence varied slightly across female sample types (range: 1.7-5.8%; p = 0.0042). MG prevalence was higher in male rectal samples (12.5%) than in male urine samples (3.9%; p < 0.0001). TV prevalence was low in male (0.8%; 12/1535) and female (1.3%; 16/1260) samples across all sites. Co-infection of TV/MG with CT or NG was 10.0% (19/190) and 9.6% (7/73), respectively, in both male and female samples. MG and TV prevalence rates were comparable to the published literature in Europe. MG prevalence was highest in male rectal samples; as rectal testing is an off-label use of the cobas TV/MG assay, the clinical utility of this assay for rectal testing should be further investigated.

Evaluation of a combined detection of SARS-CoV-2 and its variants using real-time allele-specific PCR strategy: an advantage for clinical practice.

This study aimed to assess the ability of a real-time reverse transcription polymerase chain reaction (RT-PCR) with multiple targets to detect SARS-CoV-2 and its variants in a single test. Nasopharyngeal specimens were collected from patients in Granada, Spain, between January 2021 and December 2022. Five allele-specific RT-PCR kits were used sequentially, with each kit designed to detect a predominant variant at the time. When the Alpha variant was dominant, the kit included the HV69/70 deletion, E and N genes. When Delta replaced Alpha, the kit incorporated the L452R mutation in addition to E and N genes. When Omicron became dominant, L452R was replaced with the N679K mutation. Before incorporating each variant kit, a comparative analysis was carried out with SARS-CoV-2 whole genome sequencing (WGS). The results demonstrated that RT-PCR with multiple targets can provide rapid and effective detection of SARS-CoV-2 and its variants in a single test. A very high degree of agreement (96.2%) was obtained between the comparison of RT-PCR and WGS. Allele-specific RT-PCR assays make it easier to implement epidemiological surveillance systems for effective public health decision making.

Detection of High Level of Co-Infection and the Emergence of Novel SARS CoV-2 Delta-Omicron and Omicron-Omicron Recombinants in the Epidemiological Surveillance of Andalusia.

Recombination is an evolutionary strategy to quickly acquire new viral properties inherited from the parental lineages. The systematic survey of the SARS-CoV-2 genome sequences of the Andalusian genomic surveillance strategy has allowed the detection of an unexpectedly high number of co-infections, which constitute the ideal scenario for the emergence of new recombinants. Whole genome sequence of SARS-CoV-2 has been carried out as part of the genomic surveillance programme. Sample sources included the main hospitals in the Andalusia region. In addition to the increase of co-infections and known recombinants, three novel SARS-CoV-2 delta-omicron and omicron-omicron recombinant variants with two break points have been detected. Our observations document an epidemiological scenario in which co-infection and recombination are detected more frequently. Finally, we describe a family case in which co-infection is followed by the detection of a recombinant made from the two co-infecting variants. This increased number of recombinants raises the risk of emergence of recombinant variants with increased transmissibility and pathogenicity.

Failure on voxilaprevir, velpatasvir, sofosbuvir and efficacy of rescue therapy.

BACKGROUND & AIMS: There are limited data on patients with chronic HCV infection in whom combination voxilaprevir (VOX), velpatasvir (VEL), sofosbuvir (SOF) retreatment fails. Thus, we aimed to assess treatment failure and rescue treatment options in these patients. METHODS: Samples from 40 patients with HCV genotypes (GT) 1-4 in whom VOX/VEL/SOF retreatment failed were collected within the European Resistance Study Group. Population-based resistance analyses were conducted and clinical parameters and retreatment efficacies were evaluated retrospectively in 22 patients. RESULTS: Most VOX/VEL/SOF failure patients were infected with HCV GT3a (n = 18, 45%) or GT1a (n = 11, 28%) and had cirrhosis (n = 28, 70%). Previous treatments included an NS3-inhibitor (30%), an NS5A-inhibitor (100%) and SOF (85%). Baseline RAS data from a subgroup of patients before VOX/VEL/SOF retreatment (78%) showed few NS3 RASs apart from Q80K in GT1a (40%), typical NS5A RAS patterns in most patients (74%) and no S282T in NS5B. Sequencing after VOX/VEL/SOF failure was available in 98% of patients and showed only minor changes for NS3 and NS5A RASs. In 22 patients, rescue treatment was initiated with glecaprevir, pibrentasvir alone (n = 2) or with SOF±ribavirin (n = 15), VOX/VEL/SOF±ribavirin (n = 4) or VEL/SOF and ribavirin (n = 1) for 12 to 24 weeks. Sustained virologic response was achieved in 17/21 (81%) patients with a final treatment outcome. Of these, 2 GT3a-infected patients had virologic failure after rescue treatment with VEL/SOF or glecaprevir/pibrentasvir+SOF+ribavirin, and 2 patients with cirrhosis died during treatment or before reaching SVR12. CONCLUSIONS: VOX/VEL/SOF failure was mainly observed in HCV GT3- and GT1a-infected patients with cirrhosis and was not associated with specific RAS patterns within NS3, NS5A or NS5B target regions. Rescue treatment with multiple targeted therapies was effective in most patients. LAY SUMMARY: The advent of direct-acting antivirals has enabled the effective cure of chronic hepatitis C in most patients. However, treatment failure occurs in some patients, who are often retreated with a combination regimen called VOX/VEL/SOF, which is associated with very high rates of cure. However, VOX/VEL/SOF retreatment also fails in some patients. Herein, we analysed samples from patients in whom VOX/VEL/SOF retreatment failed and we assessed the efficacy of different rescue therapies, showing that rescue treatment is effective in most patients (81%).

Macrolide and fluoroquinolone resistance of Mycoplasma genitalium in southern Spain, 2018-2019.

OBJECTIVES: In recent years, resistance in Mycoplasma genitalium (MG) to first-line (azithromycin) and second-line (moxifloxacin) treatment has been increasingly reported worldwide, however, no data regarding the south of Spain are available. METHODS: To determine resistance rates, MG-positive samples collected from June 2018 to June 2019 were analysed by sequencing the 23S rRNA and parC genes. RESULTS: A total of 77 patients (24 men having sex with men (MSM), 30 heterosexual men and 23 women) were included. Resistance-associated mutations against macrolide and fluoroquinolones were found in 36.4% (95% CI 25.7% to 48.1%) and 9.1% (95% CI 3.7% to 17.8%) of the patients, respectively. Being MSM and having had another STI in the last year were significantly associated with macrolide-resistant MG infection, while no associations were found with resistance to fluoroquinolones. CONCLUSIONS: Testing for resistance to first-line and second-line drugs against MG should be recommended for the general population and mandatory for the MSM population. We suggest that empiric azithromycin use for STI management should be avoided.

Comparison between Aptima® assays (Hologic) and the CoBAS® 6800 system (Roche) for the diagnosis of sexually transmitted infections caused by Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium.

Nowadays, it is of utmost importance to use fully validated assays for molecular-based diagnosis. In the field of sexually transmitted disease (STD), Roche and Hologic provide assays for diagnosing Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Mycoplasma genitalium (MG), and Trichomonas vaginalis (TV). A total of 212 clinical samples were tested. Aptima® Combo 2 (detecting CT and NG), Aptima® M. genitalium and the Aptima® T. vaginalis on the Panther® system were compared to CoBAS® CT/NG and CoBAS® TV/MG running on the CoBAS® 6800 system. To solve the discrepancies, Allplex™ STI Essential assay (Seegene®) and/or Sanger DNA sequencing were used. The diagnostic performance was calculated by mean of the sensitivity and specificity parameters. Aptima® (sensitivity: 98.90%, specificity: 100%), CoBAS® (sensitivity 100%, specificity: 96.67%). The CoBAS® combo (CT/NG) failed detecting NG from an anal/rectum specimen, which is not included into the validated specimens of the assay. Aptima® combo 2 produced two false positives (CT and NG), not detected by the third tests. All the assays showed an optimal diagnostic capacity, meeting the requirements for IVD DNA-based assays. All products work optimally on automatic platforms, minimizing time and risk of contamination during handling.

Prevalence of resistance-associated substitutions and retreatment of patients failing a glecaprevir/pibrentasvir regimen.

OBJECTIVES: To investigate resistance-associated substitutions (RASs) as well as retreatment efficacies in a large cohort of European patients with failure of glecaprevir/pibrentasvir. METHODS: Patients were identified from three European Resistance Reference centres in Spain, Italy and Germany. Sequencing of NS3, NS5A and NS5B was conducted and substitutions associated with resistance to direct antiviral agents were analysed. Clinical and virological parameters were documented retrospectively and retreatment efficacies were evaluated. RESULTS: We evaluated 90 glecaprevir/pibrentasvir failures [3a (n = 36), 1a (n = 23), 2a/2c (n = 20), 1b (n = 10) and 4d (n = 1)]. Ten patients were cirrhotic, two had previous exposure to PEG-interferon and seven were coinfected with HIV; 80 had been treated for 8 weeks. Overall, 31 patients (34.4%) failed glecaprevir/pibrentasvir without any NS3 or NS5A RASs, 62.4% (53/85) showed RASs in NS5A, 15.6% (13/83) in NS3 and 10% (9/90) in both NS5A and NS3. Infection with HCV genotypes 1a and 3a was associated with a higher prevalence of NS5A RASs. Patients harbouring two (n = 34) or more (n = 8) RASs in NS5A were frequent. Retreatment was initiated in 56 patients, almost all (n = 52) with sofosbuvir/velpatasvir/voxilaprevir. The overall sustained virological response rate was 97.8% in patients with end-of-follow-up data available. CONCLUSIONS: One-third of patients failed glecaprevir/pibrentasvir without resistance. RASs in NS5A were more prevalent than in NS3 and were frequently observed as dual and triple combination patterns, with a high impact on NS5A inhibitor activity, particularly in genotypes 1a and 3a. Retreatment of glecaprevir/pibrentasvir failures with sofosbuvir/velpatasvir/voxilaprevir achieved viral suppression across all genotypes.

Genetic diversity of HIV in seminal plasma remains higher than in blood after short-term antiretroviral therapy.

OBJECTIVE: To provide insight on viral kinetics and genetic diversity of HIV in seminal plasma at baseline and 1 month after initiating antiretroviral therapy (ART). PATIENTS AND METHODS: Blood and seminal samples from patients with newly diagnosed HIV were obtained before ART initiation (T0) and 1 month after ART initiation (T1). HIV env genetic diversity was studied using deep sequencing Nextera and V3 chemistry in a MiSeq Illumina platform. The number of viral quasispecies (5% cut-off) and Shannon Index were used to analyse diversity. RESULTS: Forty-seven ART-naive patients were recruited between September 2016 and November 2018. At enrolment, the number of quasispecies in blood (median 4 (IQR 2-5)) was lower than in the seminal compartment (median 6, (IQR 4-8)) (p<0.01); the Shannon Index was also higher (p<0.001) in the seminal compartment than in blood (1.77 vs 0.64). At T1, for the 13 patients with detectable HIV in both blood/seminal plasma, viral diversity remained higher (p=0.139) in seminal plasma (median 2 (IQR 1-4.5)) than in blood (median 1 (IQR 1-1.5)) Integrase inhibitors (INI)-based regimens achieved higher levels of undetectability and led more frequently to lower variability (p<0.001) than protease inhibitors (PI) or non-nucleoside reverse transcriptase inhibitors (NNRTI). CONCLUSION: We provide here further evidence of a larger genetic diversity in seminal plasma, both at diagnosis and short term after ART initiation. Our results strengthen previous findings on HIV diversity in seminal plasma. In addition, INIs decrease variability more rapidly than PI and NNRTI in both blood and seminal plasma.

Detection of sexually transmitted disease-causing pathogens from direct clinical specimens with the multiplex PCR-based STD Direct Flow Chip Kit.

Pathogens causing sexually transmitted diseases (STDs) include viruses, bacteria, and parasites. The ability to rapidly and efficiently detect these pathogens in a single reaction still remains a health challenge. The aim of this study was to evaluate the clinical reliability and accuracy of the STD Direct Flow Chip Kit (Vitro, IVD-EC approved), which can simultaneously detect up to 9 different species of STD pathogens at once. This kit enables direct analysis-direct-PCR-of clinical specimens (urine, semen, endocervical, urethral, nasopharyngeal, and perianal swabs) without DNA purification for the following pathogens: Chlamydia trachomatis (serovars A-K and L1-L3), Haemophilus ducreyi, Herpes Simplex Virus (Types I and II), Mycoplasma genitalium, Mycoplasma hominis, Neisseria gonorrhoeae, Treponema pallidum, Trichomonas vaginalis, and Ureaplasma. The Anyplex™ II STI-7 Detection Kit (Seegene, IVD-EC) was used as the reference's method. Existing discordances were resolved using either a third molecular assay or DNA sequencing. Clinical performance was evaluated at two different stages: (i) from purified DNA of three hundred and fifty-eight clinical specimens with a diagnostic sensitivity (SE) and specificity (SP) of 99.4% and 100%, respectively, and an agreement of 99% (kappa index, κ = 0.97) with the reference's method and; (ii) by direct-PCR from six hundred and thirty-three specimens rendering SE, SP, and agreement values of 98.4%, 99.9%, and 98.0% (κ = 0.95), respectively. The STD Direct Flow Chip Kit constitutes a promising alternative to routine procedures in diagnostic, allowing direct analysis of specimens and enabling the detection of a broad panel of pathogens.

Surveillance of transmitted drug resistance to integrase inhibitors in Spain: implications for clinical practice.

BACKGROUND: Integrase strand-transfer inhibitors (INSTIs) constitute at present one of the pillars of first-line ART. OBJECTIVES: To study the prevalence of and the trend in transmitted drug resistance (TDR) to INSTIs in ART-naive patients in Spain. METHODS: During the period 2012-17, 1109 patients from CoRIS were analysed. The Stanford algorithm v8.7 was used to evaluate TDR and transmission of clinically relevant resistance. To describe individual mutations/polymorphisms, the most recent IAS list (for INSTIs) and the 2009 WHO list update (for the backbone NRTIs used in combination with INSTIs in first-line treatment) were used. RESULTS: Clinically relevant resistance to the INSTI class was 0.2%: T66I, 0.1%, resistance to elvitegravir and intermediate resistance to raltegravir; and G163K, 0.1%, intermediate resistance to raltegravir and elvitegravir. No clinical resistance to dolutegravir or bictegravir was observed. The prevalence of INSTI TDR following the IAS-USA INSTI mutation list was 2.6%, with no trend towards changes in the prevalence throughout the study period. The overall prevalence of NRTI WHO mutations was 4.3%, whereas clinically relevant resistance to tenofovir, abacavir and emtricitabine/lamivudine was 1.7%, 1.9% and 0.7%, respectively. CONCLUSIONS: Given the low prevalence of clinically relevant resistance to INSTIs and first-line NRTIs in Spain, it is very unlikely that a newly diagnosed patient will present with clinical resistance to a first-line INSTI-based regimen. These patients may not benefit from INSTI and NRTI baseline resistance testing.

Detection and quantification of HBV and HCV in plasma samples by means of different molecular assays: Comparative study.

INTRODUCTION: Viral load is a very useful marker for monitoring patients infected with HBV and HCV. This work compares assays based on transcription-mediated amplification (TMA) and on real-time PCR (RT-PCR) to verify whether they can be interchangeable. MATERIAL AND METHODS: A bicentric study, in which 147 plasma samples from patients infected with HBV and 229 with HCV were analyzed, was carried out. TMA-based assays (Aptima® HBV Quant and Aptima® HCV Quant Dx, employing Panther system (Hologic®)) and RT-PCR (COBAS® AmpliPrep/COBAS® TaqMan® and COBAS® 6800) were used and the degree of concordance between them was calculated. RESULTS: Viral load was detected in both systems in 60 (40.82%) HBV samples (median log viral load: COBAS: 2.51IU/mL (IQR 2.20-3.17), Panther: 2.71IU/mL (IQR 2.21-3.22)) and in 39 (16.96%) HCV samples (median log viral load: COBAS: 3.93IU/mL (IQR 2.24-6.01), Panther: 3.80IU/mL (IQR 1.99-6.14)). The agreement between both systems was κ=0.943 for HBV and κ=0.925 for HCV. Comparison of viral load samples detected by both assays showed a hight correlation for HBV (R2=0.86) and for HCV (R2=0.97). CONCLUSIONS: Both TMA and RT-PCR based assays may be interchangeable for the management of patients infected with HBV and HCV.

Molecular and phylogenetic characterization of the monkeypox outbreak in the South of Spain.

Background and Aim: Until the May 2022 Monkeypox (MPXV) outbreak, which spread rapidly to many non-endemic countries, the virus was considered a viral zoonosis limited to some African countries. The Andalusian circuit of genomic surveillance was rapidly applied to characterize the MPXV outbreak in the South of Spain. Methods: Whole genome sequencing was used to obtain the genomic profiles of samples collected across the south of Spain, representative of all the provinces of Andalusia. Phylogenetic analysis was used to study the relationship of the isolates and the available sequences of the 2022 outbreak. Results: Whole genome sequencing of a total of 160 MPXV viruses from the different provinces that reported cases were obtained. Interestingly, we report the sequences of MPXV viruses obtained from two patients who died. While one of the isolates bore no noteworthy mutations that explain a potential heightened virulence, in another patient the second consecutive genome sequence, performed after the administration of tecovirimat, uncovered a mutation within the A0A7H0DN30 gene, known to be a prime target for tecovirimat in its Vaccinia counterpart. In general, a low number of mutations were observed in the sequences reported, which were very similar to the reference of the 2022 outbreak (OX044336), as expected from a DNA virus. The samples likely correspond to several introductions of the circulating MPXV viruses from the last outbreak. The virus sequenced from one of the two patients that died presented a mutation in a gene that bears potential connections to drug resistance. This mutation was absent in the initial sequencing before treatment.

Assessment of performance and comparison of three commercial HDV RNA detection assays: implications for diagnosis and treatment monitoring.

Objectives: Precise HDV-RNA detection and quantification are pivotal for diagnosis and monitoring of response to newly approved treatment. We evaluate the performance of three HDV RNA detection and quantification assays. Methods: Hepatitis Delta RT-PCR system kit, EurobioPlex HDV assay, and RoboGene HDV RNA Quantification kit 2.0 were used for testing 151 HBsAg-positive samples, 90 HDV-RNA negative and 61 HDV-RNA positive. We also evaluated serial dilutions of the WHO international standard for HDV, PEI 7657/12. All HDV-RNA positive samples were genotyped using a next-generation sequencing strategy. Results: Qualitative results indicated a 100% concordance between tests. Quantitative results correlated well, r2 = 0.703 (Vircell-vs-Eurobio), r2 = 0.833 (Vircell-vs-RoboGene), r2 = 0.835 (Robogene-vs-Eurobio). Bias index was 2.083 (Vircell-vs-Eurobio), -1.283 (Vircell-vs-RoboGene), and -3.36 (Robogene-vs-Eurobio). Using the WHO IS, Vircell overestimated the viral load by 0.98 log IU/mL, Eurobio by 1.46 log IU/mL, and RoboGene underestimated it by 0.98 log IU/mL. Fifty-nine samples were successfully genotyped (Genotype 1, n=52; Genotype 5, n=7; Genotype 6, n=1), with similar results for correlation and bias. Conclusion: This study underscores the necessity of using reliable HDV-RNA detection and quantification assays, as evidenced by the high concordance rates in qualitative detection and the observed variability in quantitative results. These findings highlight the importance of consistent assay use in clinical practice to ensure accurate diagnosis and effective treatment monitoring of HDV infection.

Real-life validation of a sample pooling strategy for screening of hepatitis C.

OBJECTIVES: To test a real-life sample pooling screening strategy which contributes to increasing the diagnostic capacity of clinical laboratories and expanding access to massive screening of hepatitis C. METHODS: After evaluating the sensitivity of the pooling strategy for seven different commercial assays which are used to determine the concentration of hepatitis C virus (HCV)-RNA in the plasma or serum, consecutive samples submitted for HCV diagnosis during the first 3 weeks of November 2021 were tested for HCV antibodies and, in parallel and in a blinded way, were pooled into 100 samples and tested for HCV-RNA. When the result was positive, a strategy to un-mask the positive(s) pool(s), which needed up to 15 total HCV-RNA tests, was used. RESULTS: All platforms were able to detect the presence of HCV-RNA in a single sample from a patient with viremic HCV present in pools of up to at least 10 000 HCV-RNA-free samples. A total of 1700 samples (17 pools) were analysed, with an overall prevalence of anti-HCV and HCV-RNA of 0.24%. After pooling, we could detect all samples previously detected using standard diagnosis tests (reflex testing) with a specificity and sensitivity of 100% (CI, 99.78-100%). Given the median current prices of anti-HCV and HCV-RNA on the market in Spain as well as personnel costs, testing using the pooling strategy would have resulted in a save of 3320€. CONCLUSIONS: Here, we demonstrated that by improving cost effectiveness, with no loss of sensitivity and specificity, the strategy of pooling samples may serve as an appropriate tool for use in large-scale screening of HCV.