Randomized trial of the safety and efficacy of anti-SARS-CoV-2 mAb in the treatment of patients with nosocomial COVID-19 (CATCO-NOS).

Background: Patients with nosocomial acquisition of COVID-19 have poor outcomes but have not been included in therapeutic trials to date. Methods: A pragmatic open-label randomized controlled trial of anti-SARS-CoV-2 monoclonal antibodies (mAb) was performed in hospitalized patients with nosocomial COVID-19 infection in acute care hospitals spanning a provincial health care network. Participants within 5 days of first positive test or symptom onset were randomized to standard of care (SOC) plus a single dose intravenous mAb treatment (bamlanivimab or casirivimab/imdevimab) or SOC alone on a 2:1 basis. The primary study endpoint was the need for invasive mechanical ventilation (IMV) or inpatient mortality by day 60 after randomization. Results: Forty-six participants were enrolled from 13 hospitals between February 14 and October 8, 2021: 31 in the mAb and 15 in the SOC arm. IMV or inpatient mortality up to day 60 occurred in 4 (12.9%) participants in the mAb versus 3 in the SOC arm (20.0%), difference of -7.1% (95% CI -22.5 to 13.4, p = 0.67). The study was terminated early due to lack of equipoise as effectiveness of anti-viral therapies and mAb was published in similar high-risk patient populations. Conclusions: The trial was underpowered to detect meaningful differences given its early termination. The study does highlight the feasibility of undertaking trials in this patient population using a pragmatic approach allowing for trial participation and treatment access across a large health care network and may serve as a template for future designs.

Historique: Les patients qui contractent une COVID-19 nosocomiale ont de mauvais résultats cliniques, mais n'ont pas fait partie des études thérapeutiques jusqu'à présent. Méthodologie: Les chercheurs ont mené une étude randomisée et contrôlée ouverte et pragmatique des anticorps monoclonaux (AcM) anti-SRAS-CoV-2 auprès de patients hospitalisés qui ont contracté une COVID-19 nosocomiale dans les hôpitaux de soins aigus d'un réseau de santé provincial. Dans les cinq jours suivant un premier test positif ou l'apparition des symptômes, les participants ont été divisés de manière randomisée entre la norme des soins (NdS) combinée à une monodose de traitement aux AcM par voie intraveineuse (bamlanivimab ou casirivimab-imdevimab) ou la NdS seule sur une base de deux pour un. Le critère d'évaluation primaire de l'étude était la ventilation mécanique invasive (VMI) ou la mortalité en milieu hospitalier le 60e jour après la randomisation. Résultats: Au total, 46 participants de 13 hôpitaux ont été inclus entre le 14 février et le 8 octobre 2021, soit 31 patients du volet des AcM et 15 du volet de la NdS. La VMI ou la mortalité en milieu hospitalier jusqu'au 60e jour a été observée chez quatre participants au volet des AcM (12,9 %) et trois participants du volet de la NdS (20,0 %), soit une différence de −7,1 % (IC à 95 %, −22,5 à 13,4, p = 0,67). L'étude a été interrompue précocement à cause de l'absence d'équilibre clinique, car des données sur l'efficacité des traitements antiviraux et des AcM ont été publiées au sujet de populations semblables de patients à haut risque. Conclusions: L'échantillon à l'étude était insuffisant pour déceler des différences significatives compte tenu de son interruption précoce. Cette recherche fait ressortir la faisabilité d'études auprès de cette population de patients au moyen d'une approche pragmatique pour y inclure des participants et accéder au traitement dans un vaste réseau de soins et pourrait servir de modèle pour concevoir d'autres études.

Immune-Based Therapy for Hospitalized Patients With COVID-19 and Risk of Secondary Infections: A Systematic Review and Meta-analysis.

Background: Immune-based therapies are standard-of-care treatment for coronavirus disease 2019 (COVID-19) patients requiring hospitalization. However, safety concerns related to the potential risk of secondary infections may limit their use. Methods: We searched OVID Medline, Ovid EMBASE, SCOPUS, Cochrane Library, clinicaltrials.gov, and PROSPERO in October 2020 and updated the search in November 2021. We included randomized controlled trials (RCTs). Pairs of reviewers screened abstracts and full studies and extracted data in an independent manner. We used RevMan to conduct a meta-analysis using random-effects models to calculate the pooled risk ratio (RR) and 95% CI for the incidence of infection. Statistical heterogeneity was determined using the I 2 statistic. We assessed risk of bias for all studies and rated the certainty of evidence using the Grading of Recommendations Assessment, Development, and Evaluation methodology. We conducted a meta-regression using the R package to meta-explore whether age, sex, and invasive mechanical ventilation modified risk of infection with immune-based therapies. The protocol is registered with PROSPERO (CRD42021229406). Results: This was a meta-analysis of 37 RCTs including 32 621 participants (mean age, 60 years; 64% male). The use of immune-based therapy for COVID-19 conferred mild protection for the occurrence of secondary infections (711/15 721, 4.5%, vs 616/16 900, 3.6%; RR, 0.82; 95% CI, 0.71-0.95; P = .008; I 2 = 28%). A subgroup analysis did not identify any subgroup effect by type of immune-based therapies (P = .85). A meta-regression revealed no impact of age, sex, or mechanical ventilation on the effect of immune-based therapies on risk of infection. Conclusions: We identified moderate-certainty evidence that the use of immune-based therapies in COVID-19 requiring hospitalization does not increase the risk of secondary infections.

Viral load of SARS-CoV-2 in droplets and bioaerosols directly captured during breathing, speaking and coughing.

Determining the viral load and infectivity of SARS-CoV-2 in macroscopic respiratory droplets, bioaerosols, and other bodily fluids and secretions is important for identifying transmission modes, assessing risks and informing public health guidelines. Here we show that viral load of SARS-CoV-2 Ribonucleic Acid (RNA) in participants' naso-pharyngeal (NP) swabs positively correlated with RNA viral load they emitted in both droplets >10 [Formula: see text] and bioaerosols <10 [Formula: see text] directly captured during the combined expiratory activities of breathing, speaking and coughing using a standardized protocol, although the NP swabs had [Formula: see text] 10[Formula: see text] more RNA on average. By identifying highly-infectious individuals (maximum of 18,000 PFU/mL in NP), we retrieved higher numbers of SARS-CoV-2 RNA gene copies in bioaerosol samples (maximum of 4.8[Formula: see text] gene copies/mL and minimum cycle threshold of 26.2) relative to other studies. However, all attempts to identify infectious virus in size-segregated droplets and bioaerosols were negative by plaque assay (0 of 58). This outcome is partly attributed to the insufficient amount of viral material in each sample (as indicated by SARS-CoV-2 gene copies) or may indicate no infectious virus was present in such samples, although other possible factors are identified.

Histoplasmosis acquired in Alberta, Canada: an epidemiological and genomic study.

BACKGROUND: The classic geographical range of histoplasmosis in North America primarily includes the states and provinces adjacent to the Ohio, Mississippi, and St Lawrence riverways. Although Alberta, Canada is not typically considered a region of risk for histoplasmosis, cases with suspected local acquisition have been reported. We aimed to investigate the epidemiology and geographical distribution of cases of histoplasmosis in Alberta to assess evidence for local acquisition of infections, using genomic analysis for corroboration. METHODS: We did an epidemiological and genomic investigation, in which laboratory-confirmed cases of histoplasmosis were reviewed in Alberta from 2011, when the disease became reportable, until 2018. We used data attained from Alberta Health. Travel and exposure histories and clinical features were reviewed. Definite local acquisition was defined as a case without previous travel outside Alberta or associated with a common-source outbreak within the province, whereas probable local acquisition was a sporadic case with travel outside Alberta but compelling local exposures. Genomes of selected case isolates were analysed, including those from cases suspected to have been locally acquired and imported. FINDINGS: Between Jan 1, 2011, and June 30, 2018, 45 cases of histoplasmosis were identified. Participants had a median age of 53 years (range 17-77) and 32 [71%] were male. Among 34 patients with documented travel histories, ten (29%) had never left the province. 11 cases were of definite local acquisition, including eight cases from three common-source outbreaks and three sporadic cases in patients who had never travelled outside Alberta. The common-source outbreaks all involved exposure to bats or their droppings in chimneys or attics of private dwellings or churches. Four patients had travelled outside Alberta but compelling evidence was seen for local exposure to bat guano. Genome sequencing showed that isolates from cases of definite and probable local acquisition clustered together and were genetically distinct from isolates from suspected imported cases and other published isolates. INTERPRETATION: Using epidemiological and genomic analyses, we established that cases of histoplasmosis have been acquired in Alberta, thus expanding the geographical range of Histoplasma spp much further northwest than was previously appreciated. Histoplasmosis should be considered in patients with compatible symptoms outside areas of classic geographical risk. FUNDING: None.

In adults exposed to COVID-19, hydroxychloroquine did not reduce confirmed or probable COVID-19; trial stopped for futility.

SOURCE CITATION: Boulware DR, Pullen MF, Bangdiwala AS, et al. A randomized trial of hydroxychloroquine as postexposure prophylaxis for COVID-19. N Engl J Med. 2020;383:517-25. 32492293.