Is there an interest in systematic serum screening for aspergillosis in COVID-19 patients in a medical ward?

PURPOSE: We evaluated the interest of systematic screening of serum fungal markers in patients hospitalized in a medical ward. METHODS: We retrospectively analyzed all patients hospitalized in our infectious disease department from October 1st to October 31st, 2020 for COVID-19 without prior ICU admission, and for whom systematic screening of serum fungal markers was performed. RESULTS: Thirty patients were included. The majority of patients received corticosteroids (96.7%). The galactomannan antigen assay was positive for 1/30 patients at D0, and 0/24, 0/16, 0/13 and 0/2 at D4, D7, D10 and D14 respectively. 1,3-ß-D-glucan was positive for 0/30, 1/24, 1/12, 0/12, 0/2 at D0, D4, D7, D10 and D14 respectively. No Aspergillus fumigatus PCR was positive. No cases of aspergillosis were retained. CONCLUSION: Our study does not support the interest of systematic screening of fungal markers in immunocompetent patients with COVID-19 in a conventional unit.

Early Hospital Discharge Using Remote Monitoring for Patients Hospitalized for COVID-19, Regardless of Need for Home Oxygen Therapy: A Descriptive Study.

AIM: Since beds are unavailable, we prospectively investigated whether early hospital discharge will be safe and useful in patients hospitalized for COVID-19, regardless of their need for home oxygen therapy. POPULATION AND METHODS: Extending the initial inclusion criteria, 62 patients were included and 51 benefited from home telemonitoring, mainly assessing clinical parameters (blood pressure, heart rate, respiratory rate, dyspnea, temperature) and peripheral saturation (SpO2) at follow-up. RESULTS: 47% of the patients were older than 65 years; 63% needed home oxygen therapy and/or presented with more than one comorbidity. At home, the mean time to dyspnea and tachypnea resolutions ranged from 21 to 24 days. The mean oxygen-weaning duration was 13.3 ± 10.4 days, and the mean SpO2 was 95.7 ± 1.6%. The nurses and/or doctors managed 1238 alerts. Two re-hospitalizations were required, related to transient chest pain or pulmonary embolism, but no death occurred. Patient satisfaction was good, and 743 potential days of hospitalization were saved for other patients. CONCLUSION: The remote monitoring of vital parameters and symptoms is safe, allowing for early hospital discharge in patients hospitalized for COVID-19, whether or not home oxygen therapy was required. Oxygen tapering outside the hospital allowed for a greater reduction in hospital stay. Randomized controlled trials are necessary to confirm this beneficial effect.

Cefepime vs carbapenems for treating third-generation cephalosporin-resistant AmpC ß-lactamase-hyperproducing Enterobacterales bloodstream infections: a multicenter retrospective study.

OBJECTIVES: AmpC ß-lactamase-hyperproducing Enterobacterales (ABLHE) bloodstream infections (BSI) are emerging and leading to therapeutic challenges worldwide. Prescriptions of carbapenems may lead to the emergence of resistance. This study aimed to compare cefepime with carbapenems for the treatment of third-generation cephalosporin-resistant ABLHE BSI. METHODS: This retrospective multicenter study included patients with ABLHE BSI from two tertiary hospitals in France, between July 2017 and July 2022. Non-AmpC-producing Enterobacterales, extended-spectrum ß-lactamase, and carbapenemase-producing Enterobacterales were excluded. Cefepime was prescribed only in case of minimal inhibitory concentration ≤1 mg/l. The primary outcome was 30-day in-hospital mortality from the date of index blood culture. Secondary outcomes were infection recurrence and treatment toxicity. An inverse probability of treatment weighting approach was used to balance the baseline characteristics between the two groups. RESULTS: We analyzed 164 BSI, which included 77 in the cefepime group and 87 in the carbapenem group. In the weighted cohort, the 30-day mortality rates were similar between the cefepime group (23.3%) and the carbapenem group (19.6%) with a relative risk of 1.19 (95% confidence interval, 0.61-2.33 P = 0.614). No significant difference in recurrence or toxicity was found between the two groups. CONCLUSION: This study adds evidence in favor of the use of cefepime for treating third-generation cephalosporin-resistant ABLHE BSI in case of minimal inhibitory concentration ≤ 1 mg/l, which could spare carbapenems.

Effect of weight-adjusted intermediate-dose versus fixed-dose prophylactic anticoagulation with low-molecular-weight heparin on venous thromboembolism among noncritically and critically ill patients with COVID-19: the COVI-DOSE trial, a multicenter, randomised, open-label, phase 4 trial.

Background: Venous thromboembolism is a major complication of coronavirus disease 2019 (COVID-19). We hypothesized that a weight-adjusted intermediate dose of anticoagulation may decrease the risk of venous thromboembolism COVID-19 patients. Methods: In this multicenter, randomised, open-label, phase 4, superiority trial with blinded adjudication of outcomes, we randomly assigned adult patients hospitalised in 20 French centers and presenting with acute respiratory SARS-CoV-2. Eligible patients were randomly assigned (1:1 ratio) to receive an intermediate weight-adjusted prophylactic dose or a fixed-dose of subcutaneous low-molecular-weight heparin during the hospital stay. The primary outcome corresponded to symptomatic deep-vein thrombosis (fatal) pulmonary embolism during hospitalization (COVI-DOSE ClinicalTrials.gov number: NCT04373707). Findings: Between May 2020, and April 2021, 1000 patients underwent randomisation in medical wards (noncritically ill) (80.1%) and intensive care units (critically ill) (19.9%); 502 patients were assigned to receive a weight-adjusted intermediate dose, and 498 received fixed-dose thromboprophylaxis. Symptomatic venous thromboembolism occurred in 6 of 502 patients (1.2%) in the weight-adjusted dose group and in 10 of 498 patients (2.1%) in the fixed-dose group (subdistribution hazard ratio, 0.59; 95% CI, 0.22-1.63; P = 0.31). There was a twofold increased risk of major or clinically relevant nonmajor bleeding: 5.9% in the weight-adjusted dose group and 3.1% in the fixed-dose group (P = 0.034). Interpretation: In the COVI-DOSE trial, the observed rate of thromboembolic events was lower than expected in patients hospitalized for COVID-19 infection, and the study was unable to show a significant difference in the risk of venous thromboembolism between the two low-molecular-weight-heparin regimens. Funding: French Ministry of Health, CAPNET, Grand-Est Region, Grand-Nancy Métropole.

Cerebral perfusion using ASL in patients with COVID-19 and neurological manifestations: A retrospective multicenter observational study.

BACKGROUND AND PURPOSE: Cerebral hypoperfusion has been reported in patients with COVID-19 and neurological manifestations in small cohorts. We aimed to systematically assess changes in cerebral perfusion in a cohort of 59 of these patients, with or without abnormalities on morphological MRI sequences. METHODS: Patients with biologically-confirmed COVID-19 and neurological manifestations undergoing a brain MRI with technically adequate arterial spin labeling (ASL) perfusion were included in this retrospective multicenter study. ASL maps were jointly reviewed by two readers blinded to clinical data. They assessed abnormal perfusion in four regions of interest in each brain hemisphere: frontal lobe, parietal lobe, posterior temporal lobe, and temporal pole extended to the amygdalo-hippocampal complex. RESULTS: Fifty-nine patients (44 men (75%), mean age 61.2 years) were included. Most patients had a severe COVID-19, 57 (97%) needed oxygen therapy and 43 (73%) were hospitalized in intensive care unit at the time of MRI. Morphological brain MRI was abnormal in 44 (75%) patients. ASL perfusion was abnormal in 53 (90%) patients, and particularly in all patients with normal morphological MRI. Hypoperfusion occurred in 48 (81%) patients, mostly in temporal poles (52 (44%)) and frontal lobes (40 (34%)). Hyperperfusion occurred in 9 (15%) patients and was closely associated with post-contrast FLAIR leptomeningeal enhancement (100% [66.4%-100%] of hyperperfusion with enhancement versus 28.6% [16.6%-43.2%] without, p = 0.002). Studied clinical parameters (especially sedation) and other morphological MRI anomalies had no significant impact on perfusion anomalies. CONCLUSION: Brain ASL perfusion showed hypoperfusion in more than 80% of patients with severe COVID-19, with or without visible lesion on conventional MRI abnormalities.

High Incidence of Acute Kidney Injury in Patients Treated with High-Dose Amoxicillin and Cloxacillin Combination Therapy.

High-dose amoxicillin and cloxacillin combination therapy is recommended for the empiric treatment of selected patients with infective endocarditis despite a low level of evidence. The main objective of this study was to evaluate the renal tolerance of high-dose intravenous amoxicillin and cloxacillin combination. We studied 27 patients treated with amoxicillin and cloxacillin (≥100 mg/kg daily) for at least 48 h. The primary endpoint was the occurrence of acute kidney injury (AKI). The median patient age was 68 ± 8 years, and 16 (59%) were male. The indication for this combination therapy was suspected or confirmed endocarditis with no bacterial identification in 22 (81%) patients. The primary endpoint occurred in 16 (59%) patients after initiating this combination therapy within an average of 4.4 ± 3.6 days. Among them, seven (26%) patients developed severe AKI, including four (15%) patients who required hemodialysis. Other risk factors for AKI were identified in all patients, including injection of iodinated contrast media in 21 (78%), acute heart failure in 18 (67%), cardiac surgery in 11 (41%), and aminoglycoside use in 9 (33%) patients. This study reports an incidence of 59% of AKI after initiating amoxicillin and cloxacillin combination therapy in a population at high renal risk.

Imaging strategies used in emergency departments for the diagnostic workup of COVID-19 patients during the first wave of the pandemic: a cost-effectiveness analysis.

OBJECTIVES: Emergency departments (EDs) were on the front line for the diagnostic workup of patients with COVID-19-like symptoms during the first wave. Chest imaging was the key to rapidly identifying COVID-19 before administering RT-PCR, which was time-consuming. The objective of our study was to compare the costs and organizational benefits of triage strategies in ED during the first wave of the COVID-19 pandemic. METHODS: We conducted a retrospective study in five EDs in France, involving 3712 consecutive patients consulting with COVID-like symptoms between 9 March 2020 and 8 April 2020, to assess the cost effectiveness of imaging strategies (chest radiography, chest computed tomography (CT) scan in the presence of respiratory symptoms, systematic ultra-low-dose (ULD) chest CT, and no systematic imaging) on ED length of stay (LOS) in the ED and on hospital costs. The incremental cost-effectiveness ratio was calculated as the difference in costs divided by the difference in LOS. RESULTS: Compared with chest radiography, workup with systematic ULD chest CT was the more cost-effective strategy (average LOS of 6.89 hours; average cost of €3646), allowing for an almost 4-hour decrease in LOS in the ED at a cost increase of €98 per patient. Chest radiography (extendedly dominated) and RT-PCR with no systematic imaging were the least effective strategies, with an average LOS of 10.8 hours. The strategy of chest CT in the presence of respiratory symptoms was more effective than the systematic ULD chest CT strategy, with the former providing a gain of 37 minutes at an extra cost of €718. DISCUSSION: Systematic ULD chest CT for patients with COVID-like symptoms in the ED is a cost-effective strategy and should be considered to improve the management of patients in the ED during the pandemic, given the need to triage patients.

Abnormal liver tests and non-alcoholic fatty liver disease predict disease progression and outcome of patients with COVID-19.

BACKGROUND AND AIMS: Coronavirus disease 2019 (COVID-19) is a serious public health issue that became rapidly pandemic. Liver injury and comorbidities, including metabolic syndrome, are associated with severe forms of the disease. This study sought to investigate liver injury, clinical features, and risk factors in patients with mild, moderate, and severe COVID-19. METHODS: We retrospectively included all consecutive patients hospitalized with laboratory-confirmed COVID-19 between February, 22 and May 15, 2020 at the emergency rooms of a French tertiary hospital. Medical history, symptoms, biological and imaging data were collected. RESULTS: Among the 1381 hospitalizations for COVID-19, 719 patients underwent liver tests on admission and 496 (68.9%) patients displayed abnormal liver tests. Aspartate aminotransferase was most commonly abnormal in 57% of cases, followed by gamma-glutamyl transferase, alanine aminotransferase, albumin, alkaline phosphatase, and total bilirubin in 56.5%, 35.9%, 18.4%, 11.4%, and 5.8%. The presence of hepatocellular type more than 2xULN was associated with a higher risk of hospitalization and a worse course of severe disease (odd ratio [OR] 5.599; 95%CI: 1.27-23.86; p = 0.021; OR 3.404; 95% CI: 2.12-5.47; p < 0.001, respectively). A higher NAFLD fibrosis score was associated with a higher risk of hospitalization (OR 1.754; 95%CI: 1.27-2.43, p < 0.001). In multivariate analyses, patients with high fibrosis-4 index had a 3-fold greater risk of severe disease (p < 0.001). CONCLUSION: Abnormal liver tests are common in patients with COVID-19 and could predict the outcome. Patients with non-alcoholic fatty liver disease and liver fibrosis are at higher risk of progressing to severe COVID-19.

Combining predictive markers for severe COVID-19: Torquetenovirus DNA load and SARS-CoV-2 RNAemia.

RATIONALE/OBJECTIVES: SARS-CoV-2 is the cause of worldwide COVID-19, which severity has been linked to the immune and inflammatory response. Here, we investigate Torquetenovirus (TTV) DNA load - a marker reflecting the intensity of the overall immune response - as well as SARS-CoV-2 RNAemia and IgM/IgG antibodies in COVID-19-positive patients. METHODS: Two hundred and fifteen COVID-19-positive patients were enrolled, including 87 severe cases and 128 mild-moderate cases. SARS-CoV-2 RNAemia and IgM/IgG antibodies, as well as TTV DNA loads, were measured on longitudinal plasma samples. RESULTS: The rate of severe cases was higher in patients with low TTV DNA load in plasma considering a threshold of 700 copies/mL. In severe patients, SARS-CoV-2 RNAemia positivity rates were higher than those in mild-moderate cases at any timepoint. When combined, TTV DNA load and SARS-CoV-2 RNAemia allowed to predict the outcome of COVID-19 infection, with a higher risk (HR=12.4) of ICU admission in patients with low TTV DNA load and positive SARS-CoV-2 RNAemia. CONCLUSIONS: TTV DNA load and SARS-CoV-2 RNAemia may be effective, non-invasive markers reflecting disease severity and poor outcome that could be conveniently measured in a clinical laboratory setting, as soon as COVID-19 diagnosis is made.

Cerebral mucormycosis: neuroimaging findings and histopathological correlation.

INTRODUCTION: Mucormycosis are infections caused by molds of the order Mucorales. These opportunistic infections are rare, difficult to diagnose, and have a poor prognosis. We aimed to describe common radiographic patterns that may help to diagnose cerebral mucormycosis and search for histopathological correlations with imaging data. METHODS: We studied the radiological findings (CT and MRI) of 18 patients with cerebral mucormycosis and four patients' histopathological findings. RESULTS: All patients were immunocompromised and/or diabetic. The type of lesions depended on the infection's dissemination pathway. Hematogenous dissemination lesions were most frequently abscesses (59 lesions), cortical, cortical-subcortical, or in the basal ganglia, with a halo aspect on DWI for lesions larger than 1.6 cm. Only seven lesions were enhanced after contrast injection, with different presentations depending on patients' immune status. Ischemia and hemorrhagic areas were also seen. Vascular lesions were represented by stenosis and thrombosis. Direct posterior extension lesions were bi-fronto basal hypodensities on CT and restricted diffusion without enhancement on MRI. A particular extension, perineural spread, was seen along the trigeminal nerve. Histopathological analysis found endovascular lesions with destruction of vessel walls by Mucorales, microbleeds around vessels, as well as acute and chronic inflammation. CONCLUSIONS: MRI is the critical exam for cerebral mucormycosis. Weak ring enhancement and reduced halo diffusion suggest the diagnosis of fungal infections. Involvement of the frontal lobes should raise suspicion of mucormycosis (along with aspergillosis). The perineural spread can be considered a more specific extension pathway of mucormycosis.

Fungal Infections Caused by Kazachstania spp., Strasbourg, France, 2007-2020.

Rare fungal pathogens are emerging as agents of invasive fungal infections. We analyzed 13 cases of fungal infections caused by Kazachstania (Arxiozyma) spp. in Strasbourg University Hospital, Strasbourg, France. Among the cases, 4 patients had proven fungal disease (3 cases of invasive fungal disease and 1 mucocutaneous infection) and 9 were colonized by Kazachstania (Arxiozyma) spp. Candida albicans was also isolated from 11 of the 13 patients. None of the patients with proven invasive fungal disease met host criteria, but most had underlying diseases. All strains were identified as K. telluris by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and 3 were confirmed as K. bovina by internal transcribed spacer sequencing. For all tested strains, the MICs for fluconazole were >2 µg/mL. Emergence of this rare fungal infection might be explained by the increasing number of patients with immunocompromised conditions and gastroesophageal diseases.

Revised version (INFD-D-20-00242): impact of 16S rDNA sequencing on clinical treatment decisions: a single center retrospective study.

BACKGROUND: PCRs targeting 16S ribosomal DNA (16S PCR) followed by Sanger's sequencing can identify bacteria from normally sterile sites and complement standard analyzes, but they are expensive. We conducted a retrospective study in the Strasbourg University Hospital to assess the clinical impact of 16S PCR sequencing on patients' treatments according to different sample types. METHODS: From 2014 to 2018, 806 16S PCR samples were processed, and 191 of those were positive. RESULTS: Overall, the test impacted the treatment of 62 of the 191 patients (32%). The antibiotic treatment was rationalized in 31 patients (50%) and extended in 24 patients (39%), and an invasive procedure was chosen for 7 patients (11%) due to the 16S PCR sequencing results. Positive 16S PCR sequencing results on cerebrospinal fluid (CSF) had a greater impact on patients' management than positive ones on cardiac valves (p = 0.044). The clinical impact of positive 16S PCR sequencing results were significantly higher when blood cultures were negative (p < 0.001), and this difference appeared larger when both blood and sample cultures were negative (p < 0.001). The diagnostic contribution of 16S PCR was higher in patients with previous antibiotic treatment (p < 0.001). CONCLUSION: In all, 16S PCR analysis has a significant clinical impact on patient management, particularly for suspected CSF infections, for patients with culture-negative samples and for those with previous antibiotic treatments.

Cerebrospinal Fluid Features in Patients With Coronavirus Disease 2019 and Neurological Manifestations: Correlation with Brain Magnetic Resonance Imaging Findings in 58 Patients.

BACKGROUND: Neurological manifestations are common in patients with coronavirus disease 2019 (COVID-19), but little is known about pathophysiological mechanisms. In this single-center study, we examined neurological manifestations in 58 patients, including cerebrospinal fluid (CSF) analysis and neuroimaging findings. METHODS: The study included 58 patients with COVID-19 and neurological manifestations in whom severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse-transcription polymerase chain reaction screening and on CSF analysis were performed. Clinical, laboratory, and brain magnetic resonance (MR) imaging data were retrospectively collected and analyzed. RESULTS: Patients were mostly men (66%), with a median age of 62 years. Encephalopathy was frequent (81%), followed by pyramidal dysfunction (16%), seizures (10%), and headaches (5%). CSF protein and albumin levels were increased in 38% and 23%, respectively. A total of 40% of patients displayed an elevated albumin quotient, suggesting impaired blood-brain barrier integrity. CSF-specific immunoglobulin G oligoclonal band was found in 5 patients (11%), suggesting an intrathecal synthesis of immunoglobulin G, and 26 patients (55%) presented identical oligoclonal bands in serum and CSF. Four patients (7%) had a positive CSF SARS-CoV-2 reverse-transcription polymerase chain reaction. Leptomeningeal enhancement was present on brain MR images in 20 patients (38%). CONCLUSIONS: Brain MR imaging abnormalities, especially leptomeningeal enhancement, and increased inflammatory markers in CSF are frequent in patients with neurological manifestations related to COVID-19, whereas SARS-CoV-2 detection in CSF remained scanty.

3D-printed simulator for nasopharyngeal swab collection for COVID-19.

INTRODUCTION: Testing for COVID-19 is a cornerstone of pandemic control. If conducted inappropriately, nasopharyngeal swab collection can be painful and preanalytical sample collection errors may lead to false negative results. Our objective was to develop a realistic and easily available synthetic simulator for nasopharyngeal swab collection. MATERIALS AND METHODS: The nasopharyngeal swab collection simulator was designed through different development steps: segmentation, computer-aided design (CAD), and 3D printing. The model was 3D printed using PolyJet technology, which allows multi-material printing using hard and soft materials. RESULTS: The simulator splits in the parasagittal plane close to the septum to allow better visualization and understanding of nasal cavity landmarks. The model is able to simulate the softness and texture of different structural elements. The simulator allows the user to conduct realistic nasopharyngeal swab collection. A colored pad on the posterior wall of the nasopharynx provides real-time feedback to the user. The simulator also permits incorrect swab insertion, which is of obvious benefit from a training perspective. Comprehensive 3D files for printing and full instructions for manufacturing the simulator is freely available online via an open access link. CONCLUSION: In the context of the COVID-19 pandemic, we developed a nasopharyngeal swab collection simulator which can be produced by 3D printing via an open access link, which offers complete operating instructions.

Clinical characteristics and risk factors associated with severe COVID-19: prospective analysis of 1,045 hospitalised cases in North-Eastern France, March 2020.

BackgroundIn March 2020, the COVID-19 outbreak was declared a pandemic by the World Health Organization.AimOur objective was to identify risk factors predictive of severe disease and death in France.MethodsIn this prospective cohort study, we included patients ≥ 18 years old with confirmed COVID-19, hospitalised in Strasbourg and Mulhouse hospitals (France), in March 2020. We respectively compared patients who developed severe disease (admission to an intensive care unit (ICU) or death) and patients who died, to those who did not, by day 7 after hospitalisation.ResultsAmong 1,045 patients, 424 (41%) had severe disease, including 335 (32%) who were admitted to ICU, and 115 (11%) who died. Mean age was 66 years (range: 20-100), and 612 (59%) were men. Almost 75% of patients with body mass index (BMI) data (n = 897) had a BMI ≥ 25 kg/m2 (n = 661). Independent risk factors associated with severe disease were advanced age (odds ratio (OR): 1.1 per 10-year increase; 95% CrI (credible interval): 1.0-1.2), male sex (OR: 2.1; 95% CrI: 1.5-2.8), BMI of 25-29.9 kg/m2 (OR: 1.8; 95% CrI: 1.2-2.7) or ≥ 30 (OR: 2.2; 95% CrI: 1.5-3.3), dyspnoea (OR: 2.5; 95% CrI: 1.8-3.4) and inflammatory parameters (elevated C-reactive protein and neutrophil count, low lymphocyte count). Risk factors associated with death were advanced age (OR: 2.7 per 10-year increase; 95% CrI: 2.1-3.4), male sex (OR: 1.7; 95% CrI: 1.1-2.7), immunosuppression (OR: 3.8; 95% CrI: 1.6-7.7), diabetes (OR: 1.7; 95% CrI: 1.0-2.7), chronic kidney disease (OR: 2.3; 95% CrI: 1.3-3.9), dyspnoea (OR: 2.1; 95% CrI: 1.2-3.4) and inflammatory parameters.ConclusionsOverweightedness, obesity, advanced age, male sex, comorbidities, dyspnoea and inflammation are risk factors for severe COVID-19 or death in hospitalised patients. Identifying these features among patients in routine clinical practice might improve COVID-19 management.

The BAS2IC Score: A Useful Tool to Identify Patients at High Risk of Early Progression to Severe Coronavirus Disease 2019.

We developed a score, with easily accessible data (age, sex, body mass index, dyspnea, inflammatory parameters), to predict the risk of rapid progression to severe coronavirus disease 2019. Using a cutoff of >6 points, the negative predictive value was 87%.

Serologic responses to SARS-CoV-2 infection among hospital staff with mild disease in eastern France.

BACKGROUND: The serologic response of individuals with mild forms of SARS-CoV-2 infection is poorly characterized. METHODS: Hospital staff who had recovered from mild forms of PCR-confirmed SARS-CoV-2 infection were tested for anti-SARS-CoV-2 antibodies using two assays: a rapid immunodiagnostic test (99.4% specificity) and the S-Flow assay (~99% specificity). The neutralizing activity of the sera was tested with a pseudovirus-based assay. FINDINGS: Of 162 hospital staff who participated in the investigation, 160 reported SARS-CoV-2 infection that had not required hospital admission and were included in these analyses. The median time from symptom onset to blood sample collection was 24 days (IQR: 21-28, range 13-39). The rapid immunodiagnostic test detected antibodies in 153 (95.6%) of the samples and the S-Flow assay in 159 (99.4%), failing to detect antibodies in one sample collected 18 days after symptom onset (the rapid test did not detect antibodies in that patient). Neutralizing antibodies (NAbs) were detected in 79%, 92% and 98% of samples collected 13-20, 21-27 and 28-41 days after symptom onset, respectively (P = 0.02). INTERPRETATION: Antibodies against SARS-CoV-2 were detected in virtually all hospital staff sampled from 13 days after the onset of COVID-19 symptoms. This finding supports the use of serologic testing for the diagnosis of individuals who have recovered from SARS-CoV-2 infection. The neutralizing activity of the antibodies increased overtime. Future studies will help assess the persistence of the humoral response and its associated neutralization capacity in recovered patients. FUNDINGS: The funders had no role in study design, data collection, interpretation, or the decision to submit the work for publication.