[Duration of enteric carriage of multiresistant Enterobacteriaceae: current state of the evidence]. / Durée de colonisation digestive des Enterobacteriaceae multirésistantes : connaissances actuelles.

Knowledge about the duration of digestive carriage of ESBL- and carbapenemase-producing Enterobacteriaceae is an essential information, impacting clinical decisions (empiric treatment for known carriers) and infection control measures (preemptive precautions, sequential screening). Ten to 50% carriers are still colonized after one year, but these numbers might be overestimated. Use of genomic typing is required to distinguish endogenous long-term carriage from exogenous recolonization events. Median length of colonization appears to range between 0,5 and 13 months for E-ESBL and 0,7 to 10 months for CPE. We performed a narrative review of the literature on this topic. We finally suggest a few future perspectives.

La durée de colonisation digestive par les Enterobacteriaceae productrices de bêtalactamases à spectre élargi (E-BLSE) ou de carbapénèmases (EPC) a des répercussions sur le traitement empirique des cas connus et sur l'application des mesures de contrôle de l'infection. Toutefois, cette information reposant sur une évidence hétérogène est souvent surestimée, avec 10 à 50 % des porteurs colonisés à 1 an. L'utilisation de tests diagnostiques moléculaires est nécessaire pour distinguer les porteurs chroniques avérés des événements de recontamination. La durée médiane de colonisation parmi les porteurs d'E-BLSE est comprise entre 0,5 et 13 mois et, parmi les porteurs d'EPC, entre 0,7 et 10 mois. Nous proposons une revue narrative de la littérature sur le sujet, ainsi que quelques axes de réflexion future.

Sensitivity of nasopharyngeal, oropharyngeal, and nasal wash specimens for SARS-CoV-2 detection in the setting of sampling device shortage.

In the context of an unprecedented shortage of nasopharyngeal swabs (NPS) or sample transport media during the coronavirus disease 2019 (COVID-19) crisis, alternative methods for sample collection are needed. To address this need, we validated a cell culture medium as a viral transport medium, and compared the analytical sensitivity of SARS-CoV-2 RT-PCR in nasal wash (NW), oropharyngeal swab (OPS), and NPS specimens. Both the clinical and analytical sensitivity were comparable in these three sample types. OPS and NW specimens may therefore represent suitable alternatives to NPS for SARS-CoV-2 detection.

Diagnostic accuracy of Augurix COVID-19 IgG serology rapid test.

AIMS: To validate the diagnostic accuracy of the Augurix SARS-CoV-2 IgM/IgG rapid immunoassay diagnostic test (RDT) for COVID-19. METHODS: In this unmatched 1:1 case-control study, blood samples from 46 real-time RT-PCR-confirmed SARS-CoV-2 hospitalized cases and 45 healthy donors (negative controls) were studied. Diagnostic accuracy of the IgG RDT was assessed against both an in-house recombinant spike-expressing immunofluorescence assay (rIFA), as an established reference method (primary endpoint), and the Euroimmun SARS-CoV-2 IgG enzyme-linked immunosorbent assays (ELISA) (secondary endpoint). RESULTS: COVID-19 patients were more likely to be male (61% vs 20%; P = .0001) and older (median 66 vs 47 years old; P < .001) than controls. Whole blood IgG-RDT results showed 86% and 93% overall Kendall concordance with rIFA and IgG ELISA, respectively. IgG RDT performances were similar between plasma and whole blood. Overall, RDT sensitivity was 88% (95% confidence interval [95%CI]: 70-96), specificity 98% (95%CI: 90-100), PPV 97% (95%CI: 80-100) and NPV 94% (95%CI: 84-98). The IgG-RDT carried out from 0 to 6 days, 7 to 14 days and > 14 days after the SARS-CoV-2 RT-PCR test displayed 30%, 73% and 100% positivity rates in the COVID-19 group, respectively. When considering samples taken >14 days after RT-PCR diagnosis, NPV was 100% (95%CI:90-100), and PPV was 100% (95%CI:72-100). CONCLUSIONS: The Augurix IgG-RDT done in whole blood displays a high diagnostic accuracy for SARS-CoV-2 IgG in high COVID-19 prevalence settings, where its use could be considered in the absence of routine diagnostic serology facilities.

Head-to-Head Accuracy Comparison of Three Commercial COVID-19 IgM/IgG Serology Rapid Tests.

BACKGROUND: Comparative data of SARS-CoV-2 IgM/IgG serology rapid diagnostic tests (RDTs) is scarce. We thus performed a head-to-head comparison of three RDTs. METHODS: In this unmatched case-control study, blood samples from 41 RT-PCR-confirmed COVID-19 cases and 50 negative controls were studied. The diagnostic accuracy of three commercially available COVID-19 RDTs: NTBIO (RDT-A), Orient-Gene (RDT-B), and MEDsan (RDT-C), against both a recombinant spike-expressing immunofluorescence assay (rIFA) and Euroimmun IgG ELISA, was assessed. RDT results concordant with the reference methods, and between whole blood and plasma, were established by the Kendall coefficient. RESULTS: COVID-19 cases' median time from RT-PCR to serology was 22 days (interquartile range (IQR) 13-31 days). Whole-blood IgG detection with RDT-A, -B, and -C showed 0.93, 0.83, and 0.98 concordance with rIFA. Against rIFA, RDT-A sensitivity (SN) was 92% (95% CI: 78-98) and specificity (SP) 100% (95% CI: 91-100), RDT-B showed 87% SN (95% CI: 72-95) and 98% SP (95% CI: 88-100), and RDT-C 100% SN (95% CI: 88-100) and 98% SP (95% CI: 88-100). Against ELISA, SN and SP were above 90% for all three RDTs. CONCLUSIONS: RDT-A and RDT-C displayed IgG detection SN and SP above 90% in whole blood. These RDTs could be considered in the absence of routine diagnostic serology facilities.

Daily Viral Kinetics and Innate and Adaptive Immune Response Assessment in COVID-19: a Case Series.

Viral shedding patterns and their correlations with immune responses are still poorly characterized in mild coronavirus (CoV) disease 2019 (COVID-19). We monitored shedding of viral RNA and infectious virus and characterized the immune response kinetics of the first five patients quarantined in Geneva, Switzerland. High viral loads and infectious virus shedding were observed from the respiratory tract despite mild symptoms, with isolation of infectious virus and prolonged positivity by reverse transcriptase PCR (RT-PCR) until days 7 and 19 after symptom onset, respectively. Robust innate responses characterized by increases in activated CD14+ CD16+ monocytes and cytokine responses were observed as early as 2 days after symptom onset. Cellular and humoral severe acute respiratory syndrome (SARS)-CoV-2-specific adaptive responses were detectable in all patients. Infectious virus shedding was limited to the first week after symptom onset. A strong innate response, characterized by mobilization of activated monocytes during the first days of infection and SARS-CoV-2-specific antibodies, was detectable even in patients with mild disease.IMPORTANCE This work is particularly important because it simultaneously assessed the virology, immunology, and clinical presentation of the same subjects, whereas other studies assess these separately. We describe the detailed viral and immune profiles of the first five patients infected by SARS-CoV-2 and quarantined in Geneva, Switzerland. Viral loads peaked at the very beginning of the disease, and infectious virus was shed only during the early acute phase of disease. No infectious virus could be isolated by culture 7 days after onset of symptoms, while viral RNA was still detectable for a prolonged period. Importantly, we saw that all patients, even those with mild symptoms, mount an innate response sufficient for viral control (characterized by early activated cytokines and monocyte responses) and develop specific immunity as well as cellular and humoral SARS-CoV-2-specific adaptive responses, which already begin to decline a few months after the resolution of symptoms.