SARS-CoV-2 Transmission in Belgian French-Speaking Primary Schools: An Epidemiological Pilot Study.

Schools have been a point of attention during the pandemic, and their closure one of the mitigating measures taken. A better understanding of the dynamics of the transmission of SARS-CoV-2 in elementary education is essential to advise decisionmakers. We conducted an uncontrolled non-interventional prospective study in Belgian French-speaking schools to describe the role of attending asymptomatic children and school staff in the spread of COVID-19 and to estimate the transmission to others. Each participant from selected schools was tested for SARS-CoV-2 using a polymerase chain reaction (PCR) analysis on saliva sample, on a weekly basis, during six consecutive visits. In accordance with recommendations in force at the time, symptomatic individuals were excluded from school, but per the study protocol, being that participants were blinded to PCR results, asymptomatic participants were maintained at school. Among 11 selected schools, 932 pupils and 242 school staff were included between January and May 2021. Overall, 6449 saliva samples were collected, of which 44 came back positive. Most positive samples came from isolated cases. We observed that asymptomatic positive children remaining at school did not lead to increasing numbers of cases or clusters. However, we conducted our study during a period of low prevalence in Belgium. It would be interesting to conduct the same analysis during a high prevalence period.

A comparative analysis of the outcomes of patients with influenza or COVID-19 in a tertiary hospital in Belgium.

INTRODUCTION: The COVID-19 pandemic has emerged as a global health problem, associated with high morbidity and mortality rates. The aim of this study was to compare the outcomes of hospitalized patients with COVID-19 or with seasonal influenza in a teaching hospital in Belgium. METHODS: In this retrospective, single-center cohort study, 1384 patients with COVID-19 and 226 patients with influenza were matched using a propensity score with a ratio of 3:1. Primary outcomes included admission to intensive care unit (ICU), intubation rates, hospital length of stay, readmissions within 30 days and in-hospital mortality. Secondary outcomes included pulmonary bacterial superinfection, cardiovascular complications and ECMO. RESULTS: Based on the analysis of the matched sample, patients with influenza had an increased risk of readmission within 30 days (Risk Difference (RD): 0.07, 95% CI: 0.03 to 0.11) and admission to intensive care unit (RD: 0.09, 95% CI: 0.03 to 0.15) compared with those with COVID-19. Patients with influenza had also more pulmonary bacterial superinfections (46.2% vs 7.4%) and more cardiovascular complications (32% vs 3.9%) than patients with COVID-19.However, a two-fold increased risk of mortality (RD: -0.10, 95% CI: 0.15 to -0.05) was observed in COVID-19 compared to influenza. ECMO was also more required among the COVID-19 patients who died than among influenza patients (5% vs 0%). CONCLUSIONS: COVID-19 is associated with a higher in-hospital mortality compared to influenza infection, despite a high rate of ICU admission in the influenza group. These findings highlighted that the severity of hospitalized patients with influenza should not be underestimated.

Safety, Efficacy, and Relapse of Nirmatrelvir-Ritonavir in Kidney Transplant Recipients Infected With SARS-CoV-2.

Introduction: The efficacy of nirmatrelvir-ritonavir (NR; Paxlovid, Pfizer, New York, NY) to decrease the risk of progression to severe COVID-19 in high-risk patients has been demonstrated. However, evidence in infected kidney transplant recipients (KTRs) is lacking. Moreover, NR has significant and potentially harmful interactions with calcineurin inhibitors (CNIs). Methods: In this single-center retrospective study, we included all KTRs treated with NR from April 28 to June 3, 2022. A standard management strategy of CNI dose adaptation (discontinuation of tacrolimus 12 hours before the start of NR and administration of 20% of the cyclosporine dose) and laboratory follow-up was applied. Results: A total of 14 patients were included. Compared with day-0 (day before NR initiation), day-7 plasma creatinine concentrations and SARS-CoV-2 viral loads were similar (P = 0.866) and decreased (P = 0.002), respectively. CNI trough concentrations at the end of the treatment were satisfactory, nonetheless, with high individual variability. After a median follow-up time of 34 days, no death or viral pneumonia were observed. Nevertheless, 2 patients experienced early SARS-CoV-2 infection relapses (at day-10 and day-21) associated with an increase in SARS-CoV-2 viral loads. Conclusion: NR can be used in KTRs but requires a strict protocol of drug adaptation. We observed 2 cases of early relapse after NR treatment that need further investigations.

HYGIEIA: HYpothesizing the Genesis of Infectious Diseases and Epidemics through an Integrated Systems Biology Approach.

More than two years on, the COVID-19 pandemic continues to wreak havoc around the world and has battle-tested the pandemic-situation responses of all major global governments. Two key areas of investigation that are still unclear are: the molecular mechanisms that lead to heterogenic patient outcomes, and the causes of Post COVID condition (AKA Long-COVID). In this paper, we introduce the HYGIEIA project, designed to respond to the enormous challenges of the COVID-19 pandemic through a multi-omic approach supported by network medicine. It is hoped that in addition to investigating COVID-19, the logistics deployed within this project will be applicable to other infectious agents, pandemic-type situations, and also other complex, non-infectious diseases. Here, we first look at previous research into COVID-19 in the context of the proteome, metabolome, transcriptome, microbiome, host genome, and viral genome. We then discuss a proposed methodology for a large-scale multi-omic longitudinal study to investigate the aforementioned biological strata through high-throughput sequencing (HTS) and mass-spectrometry (MS) technologies. Lastly, we discuss how a network medicine approach can be used to analyze the data and make meaningful discoveries, with the final aim being the translation of these discoveries into the clinics to improve patient care.

Monoclonal Antibody Therapy in Kidney Transplant Recipients With Delta and Omicron Variants of SARS-CoV-2: A Single-Center Case Series.

Rationale & Objective: Neutralizing monoclonal antibody treatments have shown promising preliminary results in kidney transplant recipients infected with severe acute respiratory syndrome coronavirus 2. However, their efficacy in kidney transplant recipients infected with the Omicron variant has not been reported yet. Study Design: Single-center retrospective study. Setting & Participants: We included all consecutive kidney transplant recipients treated with monoclonal antibodies for severe acute respiratory syndrome coronavirus 2 infections (positive polymerase chain reaction on nasopharyngeal swab) between June 10, 2021, and January 14, 2022. Forty-seven kidney transplant recipients were included. All patients had symptoms evolving for ≤7 days and no oxygen therapy need at monoclonal antibody infusion. Results: Symptoms at diagnosis were mainly cough (n = 25; 53%) and fever (n = 15; 32%). Eighty-three percent of the cohort (n = 39) had been vaccinated with at least 2 doses before infection, of whom 30 (77%) had demonstrated a vaccine-induced humoral response. They were treated with either casirivimab-imdevimab (n = 16; 34%) or sotrovimab (n = 31; 66%) a median of 2 days (range, 0-6 days) after the onset of symptoms. Except for 1 mild allergic reaction during casirivimab-imdevimab infusion, no side effects were reported. The median viral loads at admission (day 0) and 7 days after monoclonal antibody infusion were 2,110,027 copies/mL (range, 1,000-153,798,962 copies/mL) and 1,000 copies/mL (range, 0-10,000,000 copies/mL), respectively. Genotypes were available for 22 kidney transplant recipients (47%). Omicron, Delta, and Gamma variants were identified in 13 (59%), 8 (36%), and 1 (5%) patients, respectively. In kidney transplant recipients infected with the Omicron variant, the median viral loads at day 0 and day 7 were 752,789 copies/mL (range, 4,000-12,859,300 copies/mL) and 1,353 copies/mL (range, 0-1,211,163 copies/mL), respectively. 2 kidney transplant recipients required hospitalization immediately after sotrovimab perfusion for oxygen therapy that was weaned in 3 days, allowing patients' discharge. None were admitted to the intensive care unit or died. Limitations: Small sample size, no control group. Conclusions: Neutralizing monoclonal antibody therapy is associated with positive outcomes in kidney transplant recipients with mild coronavirus disease 2019, including those infected with the Omicron variant.

Dynamics of spreading of SARS-CoV-2 in a Belgian hemodialysis facility: The importance of the analysis of viral strains.

In-center maintenance hemodialysis (HD) patients are at high risk of acquiring coronavirus disease 2019 (COVID-19) by cross-contamination inside the unit. The aim of this study was to assess retrospectively the dynamics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission during the very first pandemic phase (March-July 2020) in a cohort of in-center maintenance HD patients and in nurses the same HD facility, using a phylogenetic approach. All SARS-CoV-2 quantitative reverse-transcription polymerase chain reaction positive patients and nurses from our HD unit-respectively 10 out of 98, and 8 out of 58- and two other positive patients dialyzed in our self-care unit were included. Whole-genome viral sequencing and phylogenetic analysis supported the cluster investigation. Five positive patients were usually dialyzed in the same room and same shift before their COVID-19 diagnosis was made. Viral sequencing performed on 4/5 patients' swabs showed no phylogenetic link between their viruses. The fifth patient (whose virus could not be sequenced) was dialyzed at the end of the dialysis room and was treated by a different nurse than the one in charge of the other patients. Three nurses shared the same virus detected in both self-care patients (one of them had been transferred to our in-center facility). The epidemiologically strongly suspected intra-unit cluster could be ruled out by viral genome sequencing. The infection control policy did not allow inter-patient contamination within the HD facility, in contrast to evidence of moderate dissemination within the nursing staff and in the satellite unit. Epidemiologic data without phylogenetic confirmation might mislead the interpretation of the dynamics of viral spreading within congregate settings.