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Background: Next-generation sequencing (NGS) is gradually replacing Sanger sequencing for HIV genotypic drug resistance testing (GRT). This work evaluated the concordance among different NGS-GRT interpretation tools in a real-life setting. Methods: Routine NGS-GRT data were generated from viral RNA at 11 Italian laboratories with the AD4SEQ HIV-1 Solution v2 commercial kit. NGS results were interpreted by the SmartVir system provided by the kit and by two online tools (HyDRA Web and Stanford HIVdb). NGS-GRT was considered valid when the coverage was >100 reads (100×) at each PR/RT/IN resistance-associated position listed in the HIVdb 9.5.1 algorithm. Results: Among 629 NGS-GRT, 75.2%, 74.2%, and 70.9% were valid according to SmartVir, HyDRA Web, and HIVdb. Considering at least two interpretation tools, 463 (73.6%) NGS-GRT had a valid coverage for resistance analyses. The proportion of valid samples was affected by viremia 10% showed fair concordance among different interpretation tools. Conclusion: This Italian survey on NGS resistance testing suggests that viremia levels and HIV subtype affect NGS-GRT coverage. Within the current routine method for NGS-GRT, only mutations with frequency >10% seem reliably detected across different interpretation tools.

Prolonged SARS-CoV-2 infections are widely described in immunosuppressed patients, but safe and effective treatment strategies are lacking. We aimed to outline our approach to treating persistent COVID-19 in patients with immunosuppression from different causes. In this case series, we retrospectively enrolled all immunosuppressed patients with persistent SARS-CoV-2 infections treated at our centers between March 2022 and February 2023. Patients received different sequential or combination regimens, including antivirals (remdesivir, nirmatrelvir/ritonavir, or molnupiravir) and/or monoclonal antibodies (mAbs) (tixagevimab/cilgavimab or sotrovimab). The main outcome was a complete virological response (negative SARS-CoV-2 RT-PCR on nasopharyngeal swabs) at the end of treatment. Fifteen patients were included as follows: eleven (11/15; 73%) with hematological disease and four (4/15; 27%) with recently diagnosed HIV/AIDS infection. Six patients (6/15; 40%) received a single antiviral course, four patients (4/15; 27%) received an antiviral and mAbs sequentially, and two patients (13%) received three lines of treatment (a sequence of three antivirals or two antivirals and mAbs). A combination of two antivirals or one antiviral plus mAbs was administered in three cases (3/15, 20%). One patient died while still positive for SARS-CoV-2, while fourteen (14/15; 93%) tested negative within 16 days after the end of treatment. The median time to negativization since the last treatment was 2.5 days. Both sequential and combination regimens used in this study demonstrated high efficacy and safety in the high-risk group of immunosuppressed patients.

In the context of SARS-CoV-2 pandemic, rapid and easy-to-perform diagnostic methods are essential to limit the spread of the virus and for the clinical management of COVID-19 patients. Although real-time polymerase chain reaction remains the “gold standard” to diagnose acute infections, this technique is expensive, requires trained personnel, well-equipped laboratory and is time-consuming. A prospective evaluation of the Abbott ID NOW COVID-19 point-of-care testing that uses isothermal nucleic acid amplification for the qualitative detection of SARS-CoV-2 RdRp gene was run in the Emergency Department during the third wave of COVID-19 pandemic. ID-NOW significantly simplified SARS-CoV-2 identification and COVID-19 patient triaging, being highly valuable in rapidly locating febrile patients in or out of COVID-19 areas, and can be considered as a first-line diagnostic test in the Emergency Room setting.

In high risk patients such as in eldery, newborns and immunosuppressed subjects, a timely diagnosis of influenza is required for the most appropriate antiviral strategy in order to avoid severe secondary respiratory complications and viral spreading. Influenza is preventable by vaccination and chemoprophylaxis and is treatable by specific antiviral indications. The need for a timely diagnosis has led to the introduction of numerous rapid diagnostic tests.These are mostly antigen detection test giving results within 30 minutes, a clinically relevant time-frame to complement with the use of antiviral medications or chemoprophylaxis strategy. When evaluating performances of rapid test for influenza viruses, it is important to consider the type and quality of specimen to be tested, as well as sensitivity and specificity of the assays. Nasal/nasopharyngeal swabs are the most frequently submitted specimens, but nasal/nasopharingeal aspirates and washs can improve the diagnostic sensitivity of the test. Only some rapid assays can be successful used with broncoalveolar washings. In this review,we evaluated the sensitivity, specificity, reproducibility and feasibility of the most currently licensed rapid tests for influenza virus A and B. A flow-chart for the laboratory diagnosis of influenza with rapid test in combination with confirmatory test is proposed.

Success of antiviral therapy for chronic hepatitis B is supported by highly sensitive PCR-based assays for Hepatitis B virus (HBV) DNA. Nucleic acid extraction from biologic specimens is technically demanding and reliable PCR results depend it. Performances of the fully automatic system COBAS AmpliPrep™/COBAS TaqMan™ 48 (CAP/CTM) (Roche, Branchburg, NJ) for HBV DNA extraction and real -time PCR quantification were assessed and compared with the end-point PCR COBAS AMPLICOR HBV Monitor (CAHBM, Roche). Analytical evaluation with a proficiency panel showed that CAP/CTM quantitated HBV DNA levels in one single run over a wide dynamic range (7 logs) with a close correlation between expected and observed values (r=0.976, interassay variability below 5%). Clinical evaluation as tested with samples from 92 HBsAg-positive patients, demonstrated excellent correlation with CAHBM (r=0.966, mean difference in quantitation: 0.36 log10 IU/ml). CAP/CTM detected 10% more viremic patients and longer period of residual viremia in those on therapy. In lamivudine (LAM)-resistant patients, reduction of HBV DNA after 12 months of Adefovir (ADF) was higher in the combination (LAM+ADF) schedule than in ADF monotherapy (5.1 vs. 3.5 logs) suggesting a benefit in continuing LAM. In conclusion,CAP/CTM can improve the management of HBV infection, the assessment of antiviral therapy and drug resistance, supporting further insights in the emerging area of drug resistance.

Background/Aims: Genotyping and subtyping of hepatitis C virus (HCV) is epidemiologically and clinically relevant to prognosis and therapeutical management of HCV infection.Aim was to study the feasibility of an “in house” direct sequencing method for the genotyping and subtyping of HCV strains compared with a commercially available genotyping assay (Inno-LiPA,VERSANT® HCV Genotype 2.0 Assay, Bayer). Methods: 74 clinical plasma samples cross-representing HCV genotypes 1 to 5 typed with the line probe assay Inno-LiPA (LiPA) were subjected to a laboratory-developed 5’UTR direct sequencing protocol (5’UTR Seq).A NS5B direct sequencing protocol (NS5B Seq) was apply to 23/74 samples (17 negative by the 5’UTR).Two libraries of 5’UTR and NS5B HCV prototypes were constructed; BioEdit 7.0.0 and ClustalW were used for alignments and phylogenetic analysis. Results: 5’UTR Seq typed 47/74 LiPA positive samples (64%). Concordance between the two assays was 91% (43/47) and 72% (31/43) for HCV genotyping and subtyping, respectively. LiPA and 5’UTR Seq discordant samples were typed by NS5B Seq. NS5B Seq typed 13/17 samples negative with 5’UTR Seq.All genotypes and subtypes detected with NS5B Seq were concordant with LiPA. 5’UTR and NS5B direct sequencing pointed out a wider HCV subtype distribution than LiPA for genotype 1, 2 and 4. By the combination of 5’UTR and NS5B direct sequencing, 81% (60/74) of LiPA positive samples were typed. Conclusion: HCV typing and subtyping with the line probe assay Inno-LiPA is highly recommended for clinical purposes.A more detailed HCV typing for epidemiologic purposes can by achieved by the direct sequencing of a region with a moderate degree of genetic variability such as NS5B. HCV NS5B analysis is more efficient in resolving viral strain genetic variability than direct sequencing of a highly conserved region such as 5’UTR.

Quantitave Polymerase Chain Reaction (PCR) for Cytomegalovirus (CMV) DNA provides highly sensitive and specific data for detecting CMV as well as monitoring the infection and determining the appropriate antiviral strategy.To determine the clinical application of a recently introduced real-time (RT) PCR assay for CMV DNA quantitation in peripheral blood leukocytes (PBLs) and defining its correlation with the commercial quantitative end-point (EP) PCR method COBAS AMPLICOR CMV Monitor and pp65 antigen test. Sequential PBL samples (n=158) from 32 liver transplanted patients with CMV asymptomatic infection and positive for CMV DNA by EP-PCR were retrospectively analysed with RT-PCR and studied according to pp65 antigen levels. A good correlation was found between RT-PCR and pp65 antigen test (r=0.691) and between the two PCR assays (r=0.761). RT-PCR data were significantly higher in pre-emptive treated patients (those with >20 pp65+positive cells, median value: 3.8 log10 copies/500,000 PBLs) than in not-treated ones (2.9 logs).According to pp65 levels of 0, 1-10, 11-20, 21-50, 51-100 and >100 positive cells/200,000 PBLs, median CMV DNA load by RT-PCR was 2.6, 3.0, 3.6, 4.0. 4.2 and 4.8, log10 copies/ 500,000 PBLs, respectively (EP-PCR CMV DNA levels: 2. 8, 2.9, 3.8, 3.7, 3.9 and 4.0 logs). For samples with >20 pp65+cells, that is above the level at which pre-emptive therapy was started, RT-PCR values were significantly higher than in groups with less than 20 pp65+cells, whereas EP-PCR values did not significantly differ and showed a slower progression rate. Dilutions of DNA from CMV AD169 strain were used to probe RT-PCR reproducibility (between and intra-assay variability < 2%) and sensitivity (100% detection rate at 10 copies/reaction, 28.5% with EP-PCR). A significant improvement is coming from the introduction of RT-PCR to the study of CMV DNA dynamics in differently CMV infected patients due to a more reliable quantitation of CMV DNA for moderate and high DNA level compared to EP-PCR with better sensitivity and specificity. RTPCR gives more precise informations on viral load kinetics for evaluating the infection progress and assessing antiviral response, significantly simplifying and accelerating the process of producing a reliable quantification of CMV DNA for clinical purposes.