Performance Assessment of the LIAISON® SARS-CoV-2 Antigen Assay On Nasopharyngeal Swabs.

The SARS-CoV-2 pandemic is ongoing worldwide, causing prolonged pressure on molecular diagnostics. Viral antigen (Ag) assays have several advantages, ranging from lower cost to shorter turnaround time to detection. Given the rare occurrence of low-load viremia, antigen assays for SARSCoV-2 have focused on nasopharyngeal swab and saliva as biological matrices, but their effectiveness must be validated. We assayed here the performances of the novel quantitative Liaison® SARSCoV-2 Ag assay on 119 nasopharyngeal swabs and obtained results were compared with Hologic Panther and Abbott m2000 RT-qPCR. The Ag assay demonstrated a good correlation with viral load, shorter turnaround time, and favorable economics. The best performance was obtained in the acute phase of disease.

Previous Humoral Immunity to the Endemic Seasonal Alphacoronaviruses NL63 and 229E Is Associated with Worse Clinical Outcome in COVID-19 and Suggests Original Antigenic Sin.

Antibody-dependent enhancement (ADE) of severe acute respiratory syndrome coronavirus-2 (SARS CoV-2) infection has been hypothesized. However, to date, there has been no in vitro or in vivo evidence supporting this. Cross-reactivity exists between SARS CoV-2 and other Coronaviridae for both cellular and humoral immunity. We show here that IgG against nucleocapsid protein of alphacoronavirus NL63 and 229E correlate with the World Health Organization's (WHO) clinical severity score ≥ 5 (incidence rate ratios was 1.87 and 1.80, respectively, and 1.94 for the combination). These laboratory findings suggest possible ADE of SARS CoV-2 infection by previous alphacoronavirus immunity.

Introduction of SARS-CoV-2 variant of concern 20h/501Y.V2 (B.1.351) from Malawi to Italy.

We report here an imported case of SARS-CoV-2 variant of concern B.1.1.351 (also known as 20H/501Y.V2 or "South African variant" or VOC 202012/02) in a 66-years old symptomatic male who returned from Malawi to Italy.

Imported SARS-CoV-2 Variant P.1 in Traveler Returning from Brazil to Italy.

We report an imported case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant P.1 detected in an asymptomatic traveler who arrived in Italy on an indirect flight from Brazil. This case shows the risk for introduction of SARS-CoV-2 variants from indirect flights and the need for continued SARS-CoV-2 surveillance.

Pilot Study: Long-Term Shedding of SARS-CoV-2 in Urine: A Threat for Dispersal in Wastewater.

Only 4 months after the beginning of SARS-CoV-2 epidemic, the world is facing a global pandemic due to a complex and insidious virus that today constantly poses new challenges. In this study, we highlight a persistent shedding of SARS-CoV-2 RNA into the urine, even in patients with a negative nasopharyngeal swab and in patients considered recovered. What does it mean? Besides the fact that the kidney is a probable site of viral replication, the prolonged viral excretion is a matter of great concern for our drainage system contamination.

Bacteremia due to Klebsiella pneumoniae isolates producing the TEM-52 extended-spectrum beta-lactamase: treatment outcome of patients receiving imipenem or ciprofloxacin.

The treatment outcome of 35 cases of bacteremia due to Klebsiella pneumoniae isolates producing TEM-52 extended-spectrum beta-lactamase was studied. Twenty-eight cases, classified as "nonfatal disease" using the McCabe and Jackson classification, were investigated with regard to ciprofloxacin and imipenem response. Because ciprofloxacin was active in vitro against 21 of 28 isolates, only the treatment outcome of the ciprofloxacin-susceptible subgroup was evaluated. Eight of 10 cases occurred in patients who experienced a complete response to imipenem; 2 of 10 failed to respond. In contrast, only 2 of 7 cases had a partial response to ciprofloxacin, and, in 5 of 7 cases, the treatment failed. Statistical analysis revealed a significant difference in the treatment outcome of the 2 groups (P=.03). Because the isolates had minimum inhibitory concentrations of ciprofloxacin close to the susceptibility breakpoint, treatment failure could be ascribed to the inability of the drug to reach therapeutic concentrations at infected sites.

A two-year analysis of risk factors and outcome in patients with bloodstream infection.

A two-year analysis was performed at our hospital to evaluate the incidence and clinical impact of bloodstream infections (BSI) in medical, surgical, and intensive care unit patients. During 1999-2000 there were 521 cases of BSI with an incidence of 10.1/1,000 admissions. The most frequent predisposing factors for BSI were intravascular catheter (56.4%) and previous use of antibiotics (50.9%). Infections were considered as primary in 67.9% of cases. Urinary tract and intravascular catheter were the most frequent source of secondary bacteremia (43.1% and 35.9%, respectively). At the time of the first positive blood culture, 83.5% of patients were receiving empirical treatment, but it was adequate in only 53.9% of cases. After antimicrobial susceptibility testing, adequate antibiotic treatment was given in 67.9% of cases. Statistical analysis of independent risk factors showed that mortality was significantly related to age (P < 0.048), rapidly-fatal diseases (P < 0.001), septic shock (P < 0.020), multiorgan failure (P < 0.001), previous use of antibiotics (P < 0.008), Enterobacteriaceae producing extended-spectrum beta-lactamases (P < 0.036), and inadequate empirical treatment (P < 0.039). Based on local epidemiology and susceptibility data, microbiology laboratories should periodically release recommendations on the optimal empirical treatment for different wards.