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In 2022-23, the human monkeypox virus (MPXV) caused a global outbreak in several non-endemic countries. Here, we evaluated the diagnostic performance of four real-time qualitative PCR assays for the laboratory diagnosis of mpox (monkeypox) monkeypox disease. From July to August 2022, 27 positive and 10 negative specimens (lesion, crust and exudate swabs) were tested in the laboratory of the Hygiene Unit of the San Martino Hospital (Genoa, Italy) by using home-made real-time PCR to detect MPXV generic G2R_G DNA. According to the manufacturer's instructions, we also retrospectively analyzed these specimens using RealCycler MONK-UX/-GX (Progenie Molecular), STANDARD M10 MPX/OPX (SD Biosensor), Novaplex MPXV (Seegene Inc.) and RealStar Orthopoxvirus PCR Kit 1.0 (Altona Diagnostics) assays, recognized as research-use-only tests. The diagnostic accuracy and sensitivity of these assays ranged from 97.3% (95% CI: 86.2-99.5%) to 100% (95% CI: 90.6-100%) and 96.3% (95% CI: 81.72-99.34%) to 100% (95% CI: 72.2-100%), respectively. The RealCycler MONK-UX and STANDARD M10 MPX/OPX did not detect one positive sample with a cycle threshold of 36. The overall specificity was 100% (95% CI: 72.2-100%), and Cohen's Kappa values ranged from 1 (95% CI: 0.67-1) to 0.93 (95% CI: 0.61-1). As they are highly accurate, reliable and user-friendly, these tests should be recommended for the routine or rapid laboratory discrimination of mpox from other rash illnesses.
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Since the beginning of the pandemic, SARS-CoV-2 has shown a great genomic variability, resulting in the continuous emergence of new variants that has made their global monitoring and study a priority. This work aimed to study the genomic heterogeneity, the temporal origin, the rate of viral evolution and the population dynamics of the main circulating variants (20E.EU1, Alpha and Delta) in Italy, in August 2020-January 2022 period. For phylogenetic analyses, three datasets were set up, each for a different main lineage/variant circulating in Italy in that time including other Italian and International sequences of the same lineage/variant, available in GISAID sampled in the same times. The international dataset showed 26 (23% Italians, 23% singleton, 54% mixed), 40 (60% mixed, 37.5% Italians, 1 singleton) and 42 (85.7% mixed, 9.5% singleton, 4.8% Italians) clusters with at least one Italian sequence, in 20E.EU1 clade, Alpha and Delta variants, respectively. The estimation of tMRCAs in the Italian clusters (including >70% of genomes from Italy) showed that in all the lineage/variant, the earliest clusters were the largest in size and the most persistent in time and frequently mixed. Isolates from the major Italian Islands tended to segregate in clusters more frequently than those from other part of Italy. The study of infection dynamics showed a positive correlation between the trend in the effective number of infections estimated by BSP model and the Re curves estimated by birth-death skyline plot. The present work highlighted different evolutionary dynamics of studied lineages with high concordance between epidemiological parameters estimation and phylodynamic trends suggesting that the mechanism of replacement of the SARS-CoV-2 variants must be related to a complex of factors involving the transmissibility, as well as the implementation of control measures, and the level of cross-immunization within the population.
Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , Phylogeny , COVID-19/epidemiology , Genomics , Italy/epidemiologyABSTRACT
SARS-CoV-2 anti-spike IgG production and protection from severe respiratory illness should be explored in greater depth after COVID-19 booster vaccination. This longitudinal observational retrospective study investigated the anti-spike IgG response elicited by the first, second and booster doses of BNT162b2 mRNA vaccine in healthcare workers (HCW) at San Martino IRCCS Policlinico Hospital (Genoa) up to the 12th month. Sequential blood sampling was performed at T0 (prior to vaccination), T1 (21 days after the 1st dose of vaccine), T2, T3, T4, T5, T6 (7 days and 1, 3, 6 and 9 months after the 2nd dose, respectively), T7 and T8 (1 and 3 months after a booster dose). A SARS-CoV-2 IgG panel (Bio-Rad, Marnes-la-Coquette, France) was used to determine levels of receptor-binding domain (RBD), spike-1 (S1), spike-2 and nucleocapsid structural proteins of SARS-CoV-2. In the 51 HCWs evaluated, seroprevalence was 96% (49/51) at T1 and 100% (51/51) from T2 to T5 for RBD and S1. At T6, only one HCW was negative. T2 [RBD = 2945 (IQR:1693-5364); S1 = 1574 (IQR:833-3256) U/mL], and T7 [RBD = 8204 (IQR:4129-11,912); S1 = 4124 (IQR:2124-6326) U/mL] were characterized by the highest antibody values. Significant humoral increases in RBD and S1 were documented at T7 and T8 compared to T2 and T4, respectively (p-value < .001). Following vaccination with BNT162b2 and a booster dose in the 9th month, naïve and healthy subjects show high antibody titers up to 12 months and a protective humoral response against COVID-19 disease lasting up to 20 months after the last booster.
Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Retrospective Studies , BNT162 Vaccine , COVID-19/prevention & control , Follow-Up Studies , Seroepidemiologic Studies , Antibodies, Viral , Health Personnel , Immunoglobulin G , mRNA VaccinesABSTRACT
OBJECTIVES: Compared with reverse transcription polymerase chain reaction (RT-PCR), rapid antigen detection tests (RADTs) for SARS-CoV-2 diagnostics are faster, less expensive, but also less accurate. Performance of RADTs is context-specific and depends on disease prevalence. In this real-world study, we assessed impact of RADTs in an inpatient setting through the entire COVID-19 emergency phase. METHODS: In this matched retrospective study, data on RT-PCR and RADT laboratory diagnoses of SARS-CoV-2 made between February 2020 and May 2023 in a large hospital were analyzed. To be included in the study, samples used for both RT-PCR and RADT had to be collected on the same day. RESULTS: Of 278,867 RT-PCR tests available, 13,321 same-day RADTs could be matched to RT-PCR. Over the entire period, RADT sensitivity and specificity were 76.4% and 99.4%, respectively. With the observed positivity rate of 9.4%, positive and negative predictive values were 92.7% and 97.6%, respectively. Compared with the periods dominated by the Alpha and Delta variants of concern, RADT accuracy was slightly lower during the Omicron phase. CONCLUSION: This real-world experience demonstrates that despite suboptimal sensitivity and some variation by predominant variants of concern and positivity prevalence, the use of RADTs is useful in hospital settings. Public health implications were discussed.
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COVID-19 , Humans , COVID-19/diagnosis , COVID-19/epidemiology , SARS-CoV-2 , Pandemics , Retrospective Studies , Sensitivity and SpecificitySubject(s)
Antiviral Agents , COVID-19 , Humans , Antiviral Agents/therapeutic use , SARS-CoV-2 , Treatment Outcome , Immunocompromised HostABSTRACT
Since May 2022, multiple human Monkeypox cases were identified in nonendemic countries, mainly among men who have sex with men. We aimed to report the features, clinical course, management, and outcome of the Monkeypox cases diagnosed in the Dermatology and Infectious Disease Units of the San Martino Hospital, Genoa, Italy. We performed an observational study of the Monkeypox cases diagnosed from July 1 until August 31, 2022, collecting clinical, laboratory, and histological data. We studied 16 Monkeypox-infected men (14 homosexual, 2 bisexual) with a median age of 37 years. Three were HIV-infected. All patients reported multiple sexual partners and/or unprotected sex in the 2 weeks before the diagnosis. Most patients had prodromal signs/symptoms before the appearance of the skin/mucosal eruption, consisting of erythematous papules/vesicles/pustules in the anogenital area, which tended to erode evolving into crusts and ulcers. Lesions were often associated with local and/or systemic symptoms. Histopathology showed overlapping features in all cases: epidermal ulceration and dermal inflammatory infiltrate consisting of lymphocytes and neutrophils with an interstitial and perivascular/peri-adnexal pattern and endothelial swelling. Concomitant sexually transmitted infections (STIs) (gonococcal/nongonococcal proctitis and anal high-risk human papillomavirus [HR-HPV] infection) were frequent. Four patients were hospitalized, and one received specific treatment. The overall outcome was good. At the follow-up visit, three patients presented skin scars. Our series confirms the features of the current Monkeypox outbreak; however, different from other studies, we found a considerable rate of concomitant STIs, such as anal HR-HPV infection, that should be kept in mind because this persistent infection is the main cause of anal cancers.
Subject(s)
Anus Diseases , Mpox (monkeypox) , Sexual and Gender Minorities , Sexually Transmitted Diseases , Male , Humans , Adult , Homosexuality, Male , Mpox (monkeypox)/epidemiology , Sexually Transmitted Diseases/epidemiology , Anus Diseases/epidemiology , Disease OutbreaksABSTRACT
BACKGROUND: Influenza and respiratory syncytial (RSV) viruses are expected to co-circulate with SARS-CoV-2 in the upcoming seasons and clinical differential diagnosis between them is difficult. Laboratory-based RT-PCR is a gold standard diagnostic method for influenza, RSV and SARS-CoV-2. The objective of this study was to estimate the diagnostic performance of a novel point-of-care RT-PCR assay STANDARD M10 Flu/RSV/SARS-CoV-2 (SD Biosensor) in a large number of clinical specimens with diversified (co)-infection patterns and viral loads. METHODS: This was a retrospective study, in which all samples were tested in both STANDARD M10 Flu/RSV/SARS-CoV-2 index and Allplex SARS-CoV-2/Respiratory Panel 1 (Seegene) reference kits. Samples with discordant results were further processed in a third resolver test (Resp-4-Plex, Abbott). RESULTS: A total of 1,019 naso-/oropharyngeal samples (50.3% positive for at least one virus) were processed in both STANDARD M10 Flu/RSV/SARS-CoV-2 and Allplex assays and the overall between-assay agreement was as high as 94.6%. Positive percent agreement of the STANDARD M10 Flu/RSV/SARS-CoV-2 was 100%, 96.6%, 97.3% and 99.4% for influenza A, B, RSV and SARS-CoV-2, respectively. The corresponding negative percent agreement was 99.7%. 100%, 100% and 98.4%, respectively. The expected positive and negative predictive values for all viruses were constantly above 96% in a reasonable range of disease prevalence. CONCLUSIONS: STANDARD M10 Flu/RSV/SARS-CoV-2 is a reliable RT-PCR assay able to detect influenza A, influenza B, RSV and SARS-CoV-2 in one hour or less, fostering a rapid differential diagnosis of common respiratory viruses.
Subject(s)
COVID-19 , Coinfection , Influenza A virus , Influenza, Human , Respiratory Syncytial Virus Infections , Respiratory Syncytial Virus, Human , Humans , Influenza, Human/diagnosis , Respiratory Syncytial Viruses , SARS-CoV-2/genetics , Respiratory Syncytial Virus Infections/diagnosis , Influenza B virus/genetics , Diagnosis, Differential , Reverse Transcriptase Polymerase Chain Reaction , Retrospective Studies , Sensitivity and Specificity , Influenza A virus/genetics , Molecular Diagnostic Techniques/methods , Real-Time Polymerase Chain Reaction/methods , COVID-19/diagnosis , Coinfection/diagnosis , Respiratory Syncytial Virus, Human/geneticsABSTRACT
SARS-CoV-2 is constantly evolving, leading to new variants. We analysed data from 4400 SARS-CoV-2-positive samples in order to pursue epidemiological variant surveillance and to evaluate their impact on public health in Italy in the period of April-December 2021. The main circulating strain (76.2%) was the Delta variant, followed by the Alpha (13.3%), the Omicron (5.3%), and the Gamma variants (2.9%). The B.1.1 lineages, Eta, Beta, Iota, Mu, and Kappa variants, represented around 1% of cases. There were 48.2% of subjects who had not been vaccinated, and they had a lower median age compared to the vaccinated subjects (47 vs. 61 years). An increasing number of infections in the vaccinated subjects were observed over time, with the highest proportion in November (85.2%). The variants correlated with clinical status; the largest proportion of symptomatic patients (59.6%) was observed with the Delta variant, while subjects harbouring the Gamma variant showed the highest proportion of asymptomatic infection (21.6%), albeit also deaths (5.4%). The Omicron variant was only found in the vaccinated subjects, of which 47% had been hospitalised. The diffusivity and pathogenicity associated with the different SARS-CoV-2 variants are likely to have relevant public health implications, both at the national and international levels. Our study provides data on the rapid changes in the epidemiological landscape of the SARS-CoV-2 variants in Italy.
Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , COVID-19/epidemiology , Italy/epidemiologyABSTRACT
Highly accurate lateral flow immunochromatographic tests (LFTs) are an important public health tool to tackle the ongoing COVID-19 pandemic. The aim of this study was to assess the comparative diagnostic performance of the novel ND COVID-19 LFT under real-world conditions. A total of 400 nasopharyngeal swab specimens with a wide range of viral loads were tested in both reverse-transcription polymerase chain reaction and ND LFT. The overall sensitivity and specificity were 85% (95% CI: 76.7−90.7%) and 100% (95% CI: 98.7−100%), respectively. There was a clear association between the false-negative rate and sample viral load: the sensitivity parameters for specimens with cycle threshold values of <25 (>3.95 × 106 copies/mL) and ≥30 (≤1.29 × 105 copies/mL) were 100% and 50%, respectively. The performance was maximized in testing samples with viral loads ≥1.29 × 105 copies/mL. These findings suggest that the ND LFT is sufficiently accurate and useful for mass population screening programs, especially in high-prevalence and resource-constrained settings or during periods when the epidemic curve is rising. Other public health implications were also discussed.
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ABSTRACT: The SARS-CoV-2 pandemic involved several changes and difficulties in the work of forensic pathologists. Postmortem nasopharyngeal swabs for the diagnosis of the SARS-CoV-2 infection are recommended before an autopsy examination by the Centers for Disease Control and Prevention.Autopsy examinations must not be performed for SARS-CoV-2 infection cases when airborne infection isolation rooms or other suitable spaces are unavailable. However, it has not yet been reported whether the presence of SARS-CoV-2 at a low viral load may be enough to infect and disseminate the contagion.Here, we report the case of a 67-year-old man found dead at home on November 9, 2020, and transferred immediately after to the Genova District Mortuary. As the first postmortem molecular nasopharyngeal swab resulted positive, a weekly sampling was carried until February 4, 2021. All the molecular tests were positive for SARS-CoV-2, including the last swab performed 87 days after the arrival of the corpse at the morgue. Virus isolation conducted on VERO E6 cells revealed no cytopathic effect indicating no viral replication as early as 18 days after the corpse's arrival at the morgue and until January 2021.Our findings suggest that the presence of the genome of SARS-CoV-2 at low viral load should not be considered a sign of an active infection but a trace of a remaining viral genome from a previous infection. Then, if the virus shows no replication activity, its molecular detection should not constitute a threat to public health. Further studies are required to establish the infection's potential and its correlation with viral load.
Subject(s)
COVID-19 , SARS-CoV-2 , Aged , Autopsy , Body Remains , COVID-19/diagnosis , Cadaver , Humans , Male , Nasopharynx , United StatesABSTRACT
The rapid and presumptive detection of SARS-CoV-2 variants may be performed using multiplex RT-PCR assays. The aim of this study was to evaluate the diagnostic performance of five qualitative RT-PCR tests as compared with next-generation sequencing (NGS). We retrospectively examined a multi-variant panel (n = 72) of SARS-CoV-2-positive nasopharyngeal swabs categorized as variants of concern (Alpha, Beta, Gamma and Delta), variants under monitoring (Iota and Kappa) and wild-type strains circulating in Liguria (Italy) from January to August 2021. First, NGS libraries of study samples were prepared and mapped to the reference genome. Then, specimens were screened for the detection of L452R, W152C, K417T, K417N, E484Q, E484K and N501Y mutations using the SARS-CoV-2 Variants II Assay Allplex, UltraGene Assay SARS-CoV-2 452R & 484K & 484Q Mutations V1, COVID-19 Ultra Variant Catcher, SARS-CoV-2 Extended ELITe MGB and Simplexa SARS-CoV-2 Variants Direct. The overall accuracy of these assays ranged from 96.9% to 100%. Specificity and sensitivity were 100% and 96-100%, respectively. We highly recommend the use of these assays as second-level tests in the routine workflow of SARS-CoV-2 laboratory diagnostics, as they are accurate, user friendly, low cost, may identify specific mutations in about 2-3 h and, therefore, optimize the surveillance of SARS-CoV-2 variants.
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OBJECTIVES: Healthcare workers (HCWs) are a priority group for seasonal influenza vaccination (SIV). The 2020/21 SIV campaign was conducted during the second wave of the COVID-19 pandemic. Vaccines, including SIV, may exert non-specific protective effects on other infectious diseases which may be ascribable to the concept of trained immunity. The aim of this study was to explore the association between 2020/21 SIV and SARS-CoV-2 positivity in a cohort of Italian HCWs. METHODS: In this observational study, a cohort of HCWs employed by a large (ca 5000 employees) referral tertiary acute-care university hospital was followed up retrospectively until the start of the COVID-19 vaccination campaign. The independent variable of interest was the 2020/21 SIV uptake. Both egg-based and cell culture-derived quadrivalent SIVs were available. The study outcome was the incidence of new SARS-CoV-2 infections, as determined by RT-PCR. Multivariable Cox regression was applied in order to discern the association of interest. RESULTS: The final cohort consisted of 2561 HCWs who underwent ≥1 RT-PCR test and accounted for a total of 94,445 person-days of observation. SIV uptake was 35.6%. During the study period, a total of 290 new SARS-CoV-2 infections occurred. The incidence of new SARS-CoV-2 was 1.62 (95% CI: 1.22-2.10) and 3.91 (95% CI: 3.43-4.45) per 1000 person-days in vaccinated and non-vaccinated HCWs, respectively, with an adjusted non-proportional hazard ratio of 0.37 (95% CI: 0.22-0.62). E-values suggested that unmeasured confounding was unlikely to explain the association. CONCLUSIONS: A lower risk of SARS-CoV-2 infection was observed among SIV recipients.
Subject(s)
COVID-19 , Influenza Vaccines , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19 Vaccines , Health Personnel , Humans , Pandemics/prevention & control , Retrospective Studies , SARS-CoV-2 , SeasonsABSTRACT
BACKGROUND: This study aimed to investigate SARS-CoV-2 transmission among co-workers at the University of Genoa, Italy, during the second COVID-19 pandemic wave. METHODS: A cross-sectional study was carried out in October 2020 - March 2021: RT-PCR confirmed cases of COVID-19 notified to the Occupational Health Service were included in the analysis. RESULTS: Among the n = 201 notified cases, contact tracing of n = 53 individuals identified n = 346 close contacts. The household setting (IRR = 36.8; 95% CI: 4.9-276.8; p < 0.001) and sharing eating areas (IRR = 19.5; 95% CI: 2.5-153.9; p = 0.005) showed the highest Secondary Attack Rates (SARs) compared to the office setting. Fatigue (IRR= 17.1; 95% CI: 5.2-55.8; p < 0.001), gastrointestinal symptoms (IRR= 6.6; 95% CI: 2.9-15.2; p< 0.001) and cough (IRR= 8.2; 95% CI: 3.7-18.2; p= p< 0.001) were associated with transmission of infection. Polysymptomatic cases (IRR= 23.1; 95% CI: 3.1-169.2; p = 0.02) were more likely to transmit the infection. Among COVID-19 index cases aged >60 years (OR = 7.7; 95% CI: 1.9-31.9; p = 0.0046) SARs were higher than in other age groups. Wearing respiratory protections by both the case and the close contact resulted an effective measure compared with no use (IRR = 0.08; 95% CI: 0.03-0.2; p = < 0.0001). CONCLUSIONS: Accurate infection monitoring and contact tracing was useful to identify the main situations Conclusions: Accurate infection monitoring and contact tracing was useful to identify the main situations of SARS-CoV-2 transmission in the workplace, and hence for risk assessment and prevention programs.
Subject(s)
COVID-19 , Contact Tracing , Cross-Sectional Studies , Humans , Pandemics , SARS-CoV-2ABSTRACT
Although the reverse transcription-polymerase chain reaction (RT-PCR) is considered a standard-of-care assay for the laboratory diagnosis of SARS-CoV-2, several limitations of this method have been described. Reverse transcription loop-mediated isothermal amplification (RT-LAMP) is an alternative molecular assay and is potentially able to overcome some intrinsic shortcomings of RT-PCR. In this study, we evaluated the diagnostic performance of the novel HG COVID-19 RT-LAMP assay. In this retrospective analysis, a total of 400 routinely collected leftover nasopharyngeal samples with a known RT-PCR result were tested by means of the HG COVID-19 RT-LAMP assay. The overall sensitivity and specificity values of HG COVID-19 RT-LAMP versus RT-PCR were 97.0% (95% CI: 93.6-98.9%) and 98.5% (95% CI: 95.7-99.7%), respectively. Inter-assay agreement was almost perfect (κ = 0.96). Concordance was perfect in samples with high viral loads (cycle threshold < 30). The average time to a positive result on RT-LAMP was 17 min. HG COVID-19 RT-LAMP is a reliable molecular diagnostic kit for detecting SARS-CoV-2, and its performance is comparable to that of RT-PCR. Shorter turnaround times and the possibility of performing molecular diagnostics in the point-of-care setting make it a valuable option for facilities without sophisticated laboratory equipment.
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BACKGROUND: The ongoing SARS-CoV-2 pandemic requires the availability of accurate and rapid diagnostic tests, especially in such clinical settings as emergency and intensive care units. The objective of this study was to evaluate the diagnostic performance of the Vivalytic SARS-CoV-2 rapid PCR kit in lower respiratory tract (LRT) specimens. METHODS: Consecutive LRT specimens (bronchoalveolar lavage and bronchoaspirates) were collected from Intensive Care Units of San Martino Hospital (Genoa, Italy) between November 2020 and January 2021. All samples underwent RT-PCR testing by means of the Allplex™ SARS-CoV-2 assay (Seegene Inc., South Korea). On the basis of RT-PCR results, specimens were categorized as negative, positive with high viral load [cycle threshold (Ct) ≤ 30] and positive with low viral load (Ct of 31-35). A 1:1:1 ratio was used to achieve a sample size of 75. All specimens were subsequently tested by means of the Vivalytic SARS-CoV-2 rapid PCR assay (Bosch Healthcare Solutions GmbH, Germany). The diagnostic performance of this assay was assessed against RT-PCR through the calculation of accuracy, Cohen's κ, sensitivity, specificity and expected positive (PPV) and negative (NPV) predictive values. RESULTS: The overall diagnostic accuracy of the Vivalytic SARS-CoV-2 was 97.3% (95% CI: 90.9-99.3%), with an excellent Cohen's κ of 0.94 (95% CI: 0.72-1). Sensitivity and specificity were 96% (95% CI: 86.5-98.9%) and 100% (95% CI: 86.7-100%), respectively. In samples with high viral loads, sensitivity was 100% (Table 1). The distributions of E gene Ct values were similar (Wilcoxon's test: p = 0.070), with medians of 35 (IQR: 25-36) and 35 (IQR: 25-35) on Vivalytic and RT-PCR, respectively (Fig. 1). NPV and PPV was 92.6% and 100%, respectively. Table 1 Demographic characteristics and data sample type of the study cases (N = 75) Male, N (%) 56 (74.6%) Age (yr), Median (IQR) 65 (31-81) BAS, N (%) 43 (57.3%) Negative 30.2% Positive-High viral load [Ct ≤ 30] 27.9% Positive-Low viral load [Ct 31-35] 41.9% BAL, N (%) 32 (42.7%) Negative 37.5% Positive-High viral load [Ct ≤ 30] 40.6% Positive-Low viral load [Ct 31-35] 21.9% Data were expressed as proportions for categorical variables. Specimens were categorized into negative, positive with high viral load [cycle threshold (Ct) ≤ 30] and positive with low viral load (Ct of 31-35). BAS bronchoaspirates, BAL bronchoalveolar lavage, Ct cycle threshold Fig. 1 Distribution of E gene cycle threshold values of the rapid PCR and RT-PCR CONCLUSIONS: Vivalytic SARS-CoV-2 can be used effectively on LRT specimens following sample liquefaction. It is a feasible and highly accurate molecular procedure, especially in samples with high viral loads. This assay yields results in about 40 min, and may therefore accelerate clinical decision-making in urgent/emergency situations.
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COVID-19 , SARS-CoV-2 , Humans , Male , Pandemics , Respiratory System , Sensitivity and SpecificityABSTRACT
Extraction-based real-time reverse transcription quantitative polymerase chain reaction (RT-qPCR) is currently the "gold standard" in SARS-CoV-2 diagnostics. However, some extraction-free RT-qPCR techniques have recently been developed. In this study, we compared the sensitivity of traditional extraction-based, heated extraction-free, and unheated extraction-free RT-qPCR methods for SARS-CoV-2 detection in nasopharyngeal swabs from symptomatic individuals. The unheated extraction-free method showed perfect agreement with the standard extraction-based RT-qPCR. By contrast, the heat-treated technique was associated with an 8.2% false negativity rate. Unheated extraction-free RT-qPCR for the molecular diagnosis of SARS-CoV-2 is a valuable alternative to the traditional extraction-based methods and may accelerate turnaround times by about two hours.
Subject(s)
COVID-19 Nucleic Acid Testing , COVID-19/diagnosis , SARS-CoV-2/isolation & purification , Specimen Handling/methods , Humans , RNA, Viral/genetics , SARS-CoV-2/genetics , Sensitivity and Specificity , Specimen Handling/standardsABSTRACT
BACKGROUND: The availability of accurate and rapid diagnostic tools for COVID-19 is essential for tackling the ongoing pandemic. Our study aimed to quantify the performance of available antigen-detecting rapid diagnostic tests (Ag-RDTs) in a real-world hospital setting. METHODS: In this retrospective analysis, the diagnostic performance of 7 Ag-RDTs was compared with real-time reverse transcription quantitative polymerase chain reaction assay in terms of sensitivity, specificity and expected predictive values. RESULTS: A total of 321 matched Ag-RDTreal-time reverse transcription quantitative polymerase chain reaction samples were analyzed retrospectively. The overall sensitivity and specificity of the Ag-RDTs was 78.7% and 100%, respectively. However, a wide range of sensitivity estimates by brand (66.0%-93.8%) and cycle threshold (Ct) cut-off values (Ct <25: 96.2%; Ct 30-35: 31.1%) was observed. The optimal Ct cut-off value that maximized sensitivity was 29. CONCLUSIONS: The routine use of Ag-RDTs may be convenient in moderate-to-high intensity settings when high volumes of specimens are tested every day. However, the diagnostic performance of the commercially available tests may differ substantially.
Subject(s)
Antigens, Viral/analysis , COVID-19 Serological Testing/methods , COVID-19/diagnosis , SARS-CoV-2/immunology , COVID-19 Nucleic Acid Testing , Hospitals , Humans , Retrospective Studies , Sensitivity and SpecificityABSTRACT
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
ABSTRACT
With the aim to explore innovative tools for organ preservation, especially in marginal organs, we hereby describe a clinical trial of ex-vivo hypothermic oxygenated perfusion (HOPE) in the field of liver (LT) and kidney transplantation (KT) from Extended Criteria Donors (ECD) after brain death. A matched-case analysis of donor and recipient variables was developed: 10 HOPE-ECD livers and kidneys (HOPE-L and HOPE-K) were matched 1:3 with livers and kidneys preserved with static cold storage (SCS-L and SCS-K). HOPE and SCS groups resulted with similar basal characteristics, both for recipients and donors. Cumulative liver and kidney graft dysfunction were 10% (HOPE L-K) vs. 31.7%, in SCS group (p = 0.05). Primary non-function was 3.3% for SCS-L vs. 0% for HOPE-L. No primary non-function was reported in HOPE-K and SCS-K. Median peak aspartate aminotransferase within 7-days post-LT was significantly higher in SCS-L when compared to HOPE-L (637 vs.344 U/L, p = 0.007). Graft survival at 1-year post-transplant was 93.3% for SCS-L vs. 100% of HOPE-L and 90% for SCS-K vs. 100% of HOPE-K. Clinical outcomes support our hypothesis of machine perfusion being a safe and effective system to reduce ischemic preservation injuries in KT and in LT.
Subject(s)
Graft Survival , Kidney Transplantation/instrumentation , Liver Transplantation/instrumentation , Organ Preservation/instrumentation , Perfusion/instrumentation , Tissue Donors , Aged , Aspartate Aminotransferases/metabolism , Cold Temperature , Female , Humans , Infusion Pumps/adverse effects , Infusion Pumps/standards , Kidney/metabolism , Kidney Transplantation/methods , Liver/metabolism , Liver Transplantation/methods , Male , Middle Aged , Organ Preservation/methods , Oxygenators, Membrane/adverse effects , Oxygenators, Membrane/standards , Perfusion/methodsABSTRACT
BACKGROUND: Extended criteria donors (ECD) are widely utilized due to organ shortage, but they may increase the risk of graft dysfunction and poorer outcomes. Hypothermic oxygenated perfusion (HOPE) is a recent organ preservation strategy for marginal kidney and liver grafts, allowing a redirect from anaerobic metabolism to aerobic metabolism under hypothermic conditions and protecting grafts from oxidative species-related damage. These mechanisms may improve graft function and survival. OBJECTIVE: With this study, we will evaluate the benefit of end-ischemic HOPE on ECD grafts for livers and kidneys as compared to static cold storage (SCS). The aim of the study is to demonstrate the ability of HOPE to improve graft function and postoperative outcomes of ECD kidney and liver recipients. METHODS: This is an open-label, single-center randomized clinical trial with the aim of comparing HOPE with SCS in ECD kidney and liver transplantation. In the study protocol, which has been approved by the ethics committee, 220 patients (110 liver recipients and 110 kidney recipients) will be enrolled. Livers and kidneys assigned to the HOPE group undergo machine perfusion with cold Belzer solution (4-10°C) and continuous oxygenation (partial pressure of oxygen of 500-600 mm Hg). In the control group, livers and kidneys undergoing SCS are steeped in Celsior solution and stored on ice. Using the same perfusion machine for both liver and kidney grafts, organs are perfused from the start of the back-table procedure until implantation, without increasing the cold ischemia time. For each group, we will evaluate clinical outcomes, graft function tests, histologic findings, perfusate, and the number of allocated organs. Publication of the results is expected to begin in 2021. RESULTS: Dynamic preservation methods for organs from high-risk donors should improve graft dysfunction after transplantation. To date, we have recruited 108 participants. The study is ongoing, and recruitment of participants will continue until January 2020. CONCLUSIONS: The proposed preservation method should improve ECD graft function and consequently the postoperative patient outcomes. TRIAL REGISTRATION: ClinicalTrials.gov NCT03837197; https://clinicaltrials.gov/ct2/show/NCT03837197 ; Archived by WebCite® at http://www.webcitation.org/76fSutT3R. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/13922.