Exploring early COVID-19 therapies, variants, and viral clearance dynamics: Insights from a high-risk outpatients study.

This retrospective observational study investigates the impact of early COVID-19 therapies, including antivirals and monoclonal antibodies (mAbs), on time to achieve negative swab results in high-risk outpatients infected with specific Omicron sublineages. The study enrolled 104 patients from Luigi Sacco Hospital in Milan between December 2021 and March 2023, categorizing them based on the Omicron sublineage they were infected with (BA.1, BA.

Early administration of nirmatrelvir/ritonavir leads to faster negative SARS-CoV-2 nasal swabs than monoclonal antibodies in COVID 19 patients at high-risk for severe disease.

Purpose: Besides the well-established efficacy in preventing severe COVID-19, the impact of early treatments, namely antivirals and monoclonal antibodies (mAbs), on the time length to negativization of SARS-CoV-2 nasal swabs is still unclear. The aim of this study was to compare the efficacy of different early treatments in reducing the SARS-CoV-2 viral shedding, identifying a single drug that might potentially lead to a more rapid negativization of SARS-CoV-2 nasal swab.

Methods: This was a single-centre, retrospective, observational study conducted at Ospedale Luigi Sacco in Milan.

Epidemiology and molecular analyses of respiratory syncytial virus in the 2021-2022 season in northern Italy.

Background: Human respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infection among infants and young children worldwide, with seasonal peaks in January and February. This study aimed to characterize the RSV samples from a pediatric cohort in the 2021-2022 season in Italy.

Methods: In total, 104 samples were collected from pediatric patients attending the "Vittore Buzzi" Children's Hospital in Milan, Italy in the 2021-2022 season.

Fetal Myocarditis Associated With Maternal SARS-CoV-2 Infection.

We report the first case of significant fetal myocardial involvement associated with maternal SARS-CoV-2 infection, in which restoration of cardiac function at birth was noted. The demonstration of previous infection was supported by the quantification of humoral response in child and mother, in particular the presence of anti-N antibodies and through the detection of specific antibodies against the BA.4/5 variant.

Genomic epidemiology and phylogenetics applied to the study of SARS-CoV-2 pandemic.

The study of characteristics, prevalence and patterns of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections is significant to monitor and define the status of the pandemic, helping to design and evaluate control strategies. In this setting, the continuous emergence of new variants and their dynamic of replacement underline the importance of implementing genomic epidemiology and phylogenetic methods for the molecular monitoring and surveillance of this new virus. The current profile of the pandemic can change rapidly when new variants emerge and spread, impacting epidemiology and public health in terms of prevention and treatment and making it necessary to develop new molecules and formulate vaccines.

Efficacy of Licensed Monoclonal Antibodies and Antiviral Agents against the SARS-CoV-2 Omicron Sublineages BA.1 and BA.2.

Newly emerging SARS-CoV-2 variants may escape monoclonal antibodies (mAbs) and antiviral drugs. By using live virus assays, we assessed the ex vivo inhibition of the B.1 wild-type (WT), delta and omicron BA.

Evidence of SARS-CoV-2 Antibodies and RNA on Autopsy Cases in the Pre-Pandemic Period in Milan (Italy).

In this study, we analyzed blood samples obtained from 169 cadavers subjected to an autopsy from 1 October 2019 to 27 March 2020. The presence of anti-severe acute respiratory syndrome coronavirus 2 (anti-SARS-CoV-2) antibodies was searched by lateral flow immunochromatographic assay (LFIA) and ELISA tests and the SARS-CoV-2 RNA was tested in blood and available lung tissues by real-time PCR (RT-PCR) and droplet digital PCR (ddPCR). Five cases resulted in positives at the serological screening for anti-SARS-CoV-2.

Phylogeography and genomic epidemiology of SARS-CoV-2 in Italy and Europe with newly characterized Italian genomes between February-June 2020.

The aims of this study were to characterize new SARS-CoV-2 genomes sampled all over Italy and to reconstruct the origin and the evolutionary dynamics in Italy and Europe between February and June 2020. The cluster analysis showed only small clusters including < 80 Italian isolates, while most of the Italian strains were intermixed in the whole tree. Pure Italian clusters were observed mainly after the lockdown and distancing measures were adopted.

Phylogeographical and evolutionary history of virus; a question of timescales?

Aim of this study was to reconstruct the phylogeography of virus (VARV) in the XX century, using 47 VARV whole genome sequences available in public databases, through two different methods for ancestral character reconstruction: a frequently used Bayesian framework and a fast maximum-likelihood (ML) based method. The substitution rate of the whole VARV genome was estimated to be between 6.7×10 and 1.

Durability of Humoral Responses after the Second Dose of mRNA BNT162b2 Vaccine in Residents of a Long Term Care Facility.

Residents of long-term care facilities (LTCFs) have been dramatically hit by the COVID-19 pandemic on a global scale as older age and comorbidities pose an increased risk of severe disease and death. The aim of the study was to assess the quantity and durability of specific antibody responses to SARS-CoV-2 after the first cycle (two doses) of BNT162b2 vaccine. To achieve this, SARS-CoV-2 Spike-specific IgG (S-IgG) titers was evaluated in 432 residents of the largest Italian LTCF at months 2 and 6 after vaccination.

Anti-SARS-CoV-2 Immunoglobulin Isotypes, and Neutralization Activity Against Viral Variants, According to BNT162b2-Vaccination and Infection History.

Purpose: To compare SARS-CoV-2 antigen-specific antibody production and plasma neutralizing capacity against B.1 wild-type-like strain, and Gamma/P.1 and Delta/B.

The Longest Persistence of Viable SARS-CoV-2 With Recurrence of Viremia and Relapsing Symptomatic COVID-19 in an Immunocompromised Patient-A Case Study.

Background: Immunocompromised patients show prolonged shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in nasopharyngeal swabs. We report a case of prolonged persistence of viable SARS-CoV-2 associated with clinical relapses of coronavirus disease 2019 (COVID-19) in a patient with mantle cell lymphoma who underwent treatment with rituximab, bendamustine, cytarabine with consequent lymphopenia and hypogammaglobulinemia.

Methods: Nasopharyngeal swabs and blood samples were tested for SARS-CoV-2 by real-time polymerase chain reaction (RT-PCR).

COVID-19: an outbreak in a nursing home in spring 2021.

Introduction: Nursing home residents were the most vulnerable population to be affected by Coronavirus disease 2019 (COVID-19) in Italy. The Italian vaccination strategy decided to indicate them as the target population in the first phase of the massive vaccination campaign. We carried out an analysis on an outbreak of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection which occurred in a nursing home in northern Italy (Cremona) after the administration of the complete vaccination cycle affecting most of the guests of the structure.

Circulating SARS-CoV-2 variants in Italy, October 2020-March 2021.

A growing number of emerging SARS-CoV-2 variants is being identified worldwide, potentially impacting the effectiveness of current vaccines. We report the data obtained in several Italian regions involved in the SARS-CoV-2 variant monitoring from the beginning of the epidemic and spanning the period from October 2020 to March 2021.

Early-Transmitted Variants and Their Evolution in a HIV-1 Positive Couple: NGS and Phylogenetic Analyses.

We had access to both components of a couple who became infected with human immunodeficiency virus (HIV)-1 through sexual behavior during the early initial phase of infection and before initiation of therapy. We analyzed blood samples obtained at the time of diagnosis and after six months of combined antiretroviral therapy. Next-generation sequencing (NGS) and phylogenetic analyses were used to investigate the transmission and evolution of HIV-1 quasispecies.

Human-to-Cat SARS-CoV-2 Transmission: Case Report and Full-Genome Sequencing from an Infected Pet and Its Owner in Northern Italy.

There have been previous reports of the human-to-cat transmission of SARS-CoV-2, but there are only a few molecular studies that have compared the whole genome of the virus in cats and their owners. We here describe a case of domestic SARS-CoV-2 transmission from a healthcare worker to his cat for which nasopharyngeal swabs of both the cat and its owner were used for full-genome analysis. The results indicate that quarantine measures should be extended to pets living in SARS-CoV-2-infected households.

Dynamics of the seroprevalence of SARS-CoV-2 antibodies among healthcare workers at a COVID-19 referral hospital in Milan, Italy.

Objectives: Healthcare workers (HCWs) are at high risk of developing SARS-CoV-2 infection. The aim of this single-centre prospective study was to evaluate the trend of SARS-CoV-2 seroprevalence in HCWs working at the primary referral centre for infectious diseases and bioemergencies (eg, COVID-19) in Northern Italy and investigate the factors associated with seroconversion.

Methods: Six hundred and seventy-nine HCW volunteers were tested for anti-SARS-CoV-2 antibodies three times between 4 March and 27 May 2020 and completed a questionnaire covering COVID-19 exposure, symptoms and personal protective equipment (PPE) training and confidence at each time.

SARS-CoV-2 seroprevalence trends in healthy blood donors during the COVID-19 outbreak in Milan.

Background: The Milan metropolitan area in Northern Italy was among the most severely hit by the SARS-CoV-2 outbreak. The aim of this study was to examine the seroprevalence trends of SARS-CoV-2 in healthy asymptomatic adults, and the risk factors and laboratory correlates of positive tests.

Materials And Methods: We conducted a cross-sectional study in a random sample of blood donors, who were asymptomatic at the time of evaluation, at the beginning of the first phase (February 24 to April 8 2020; n=789).

Marked decrease in acquired resistance to antiretrovirals in latest years in Italy.

Objectives: The aim of this study was to evaluate acquired drug resistance in Italy in the 2009-2018 period.

Methods: We analysed 3094 patients from the Italian ARCA database who had failed antiretroviral treatment and who had received a genotypic test after 6 months of treatment. Drug resistance mutations were identified using International AIDS Society (IAS)-USA tables and the Stanford HIVdb algorithm.