Post‑COVID‑19 Syndrome in Outpatients: A Cohort Study (preprint)

Background: Some patients experience persistent symptoms after COVID-19, but data on outpatients with mild-to-moderate COVID-19 are scarce. We aimed to describe the post-COVID-19 syndrome in confirmed COVID-19 outpatients and to identify its predictors.Methods: This monocentric prospective cohort study included symptomatic outpatients with PCR-confirmed COVID-19 (COVID-positive) and SARS-CoV-2 negative PCR (COVID-negative). Predefined persistent symptoms were evaluated though a phone interview between more than three to ten months after diagnosis. Associations between long-term symptoms and PCR test result, as well predictors of persistent symptoms in COVID-positive were evaluated by multivariate logistic regression.Findings: The study population consisted mostly of young (median of 41 versus 36 years in COVID-positive and COVID-negative, respectively; p=0·020) health care workers (67% versus 82%; p=0·006). Persistent symptoms were reported by 223 (53%) COVID-positive and 33 (37%) COVID-negative ( p =0·006). Overall, 21% COVID-positive and 15% COVID-negative (p=0·182) consulted a doctor for these symptoms. Four surveyed symptoms were independently associated with COVID-19: fatigue (adjusted odds ratio [aOR] 2·14, 95%CI 1·04-4·41), smell/taste disorder (26·5, 3·46-202), dyspnea (2·81, 1·10-7·16) and memory impairment (5·71, 1·53-21·3). Among COVID-positive, female gender (aOR 1·67, 95% CI 1·09-2·56) and overweight/obesity (1·67, 1·10-2·56) were predictors of persistent symptoms.Interpretation: More than half of COVID-positive outpatients report persistent symptoms up to ten months after infection and 21% seek medical care for this reason. The symptoms and predictors of post-COVID-19 syndrome need further characterization as it places a significant burden on society and especially healthcare systems.Funding: This work was supported by an academic award of the Leenaards Foundation.Declaration of Interests: None to declare. Ethics Approval Statement: The project was approved by the Ethics Committee of the Canton of Vaud, Switzerland. All participants gave their verbal consent to participate in this study during the phone interview (project-ID CER-VD 2020-01107 and 2019-02283).

Post-COVID-19 syndrome in outpatients: a cohort study (preprint)

BackgroundAfter mild COVID-19, some outpatients experience persistent symptoms. However, data are scarce and prospective studies are urgently needed. ObjectivesTo characterize the post-COVID-19 syndrome after mild COVID-19 and identify predictors. ParticipantsOutpatients with symptoms suggestive of COVID-19 with (1) PCR-confirmed COVID-19 (COVID-positive) or (2) SARS-CoV-2 negative PCR (COVID-negative). DesignMonocentric cohort study with prospective phone interview between more than three months to ten months after initial visit to the emergency department and outpatient clinics. Main MeasuresData of the initial visits were extracted from the electronic medical file. Predefined persistent symptoms were assessed through a structured phone interview. Associations between long-term symptoms and PCR results, as well as predictors of persistent symptoms among COVID-positive, were evaluated by multivariate logistic regression adjusted for age, gender, smoking, comorbidities, and timing of the survey. Key resultsThe study population consisted of 418 COVID-positive and 89 COVID-negative patients, mostly young adults (median age of 41 versus 36 years in COVID-positive and COVID-negative, respectively; p=0.020) and health care workers (67% versus 82%; p=0.006). Median time between the initial visit and the phone survey was 150 days in COVID-positive and 242 days in COVID-negative patients. Persistent symptoms were reported by 223 (53%) COVID-positive and 33 (37%) COVID-negative patients (p=0.006). Overall, 21% COVID-positive and 15% COVID-negative patients (p=0.182) attended care for this purpose. Four surveyed symptoms were independently associated with COVID-19: fatigue (adjusted odds ratio [or] 2.14, 95%CI 1.04-4.41), smell/taste disorder (26.5, 3.46-202), dyspnea (2.81, 1.10-7.16) and memory impairment (5.71, 1.53-21.3). Among COVID-positive, female gender (1.67, 1.09-2.56) and overweight/obesity (1.67, 1.10-2.56) were predictors of persistent symptoms. ConclusionsMore than half of COVID-positive outpatients report persistent symptoms up to ten months after a mild disease. Only 4 of 14 symptoms were associated with COVID-19 status. The symptoms and predictors of the post-COVID-19 syndrome need further characterization as this condition places a significant burden on society.

Clinical importance of reporting SARS-CoV-2 viral loads across the different stages of the COVID-19 pandemic (preprint)

On April 25th, corresponding to the first deconfinement phase after the end of the lockdown in Switzerland, a universal admission screening strategy for COVID-19 was introduced in our hospital. All patients, including asymptomatic patients were tested for SARS-CoV-2 by quantitative reverse transcription polymerase chain reaction (RT-PCR). In addition to a qualitative answer, providing viral load values to the RT-PCR results not only helped the clinician to evaluate the stage of the infection but addressed patient contagiousness and guided infection control decisions. Here, we discuss the importance of reporting viral load values when a shift from a symptomatic to a universal screening strategy was performed.

Comparison of SARS-CoV-2 serological tests with different antigen targets (preprint)

BackgroundThese last months, dozens of SARS-CoV-2 serological tests have become available with varying performances. A major effort was completed to compare 17 serological tests. MethodsIn a preliminary phase, we compared 17 IgG, IgM, IgA and pan Ig serological tests including ELISA, LFA, CLIA and ECLIA on a panel of 182 sera, comprising 113 sera from hospitalized patients with a positive RT-PCR, and 69 sampled before 1st November 2019, expected to give a positive and negative results, respectively. In a second phase, the five best performing and most available tests were further evaluated on a total of 582 sera (178 and 404 expected positive and negative, respectively), allowing the assessment of 20 possible cross-reactions with other virus. ResultsIn the preliminary phase, among eight IgG/pan-Ig ELISA or CLIA/ECLIA tests, four had a sensitivity and specificity above 90% and 98% respectively, and on six IgM/IgA tests, only one was acceptable. Only one LFA test on three showed good performances for both IgG and IgM. For all the tests IgM and IgG aroused concomitantly. In the second phase, no tests showed particular cross-reaction. We observed an important heterogeneity in the development of the antibody response, and that anti-nucleocapside (anti-N) antibodies appeared earlier than the anti-spike (anti-S) proteins. ConclusionsThe identified SARS-CoV-2 serology tests may be used for the diagnostic of CoviD-19 for negative RT-PCR patients presenting severe to mild suggestive symptoms or particular clinical presentation. Detection of both anti-N and anti-S could be complementary to increase the sensitivity of the analysis.

Indication for SARS-CoV-2 serology: first month follow-up (preprint)

SARS-CoV-2 detection is mainly performed by RT-PCR but recently serological tests were made available. A first one month follow-up of the SARS-CoV-2 serology records was performed in our laboratory to precise the diversity and proportion of the SARS-CoV-2 serology test indications and to identify new valid indications (meningoencephalitis, vasculitis, ...)

Epidemiology, risk factors and clinical course of SARS-CoV-2 infected patients in a Swiss university hospital: an observational retrospective study (preprint)

BackgroundCoronavirus disease 2019 (COVID-19) is now a global pandemic with Europe and the USA at its epicenter. Little is known about risk factors for progression to severe disease in Europe. This study aims to describe the epidemiology of COVID-19 patients in a Swiss university hospital. MethodsThis retrospective observational study included all adult patients hospitalized with a laboratory confirmed SARS-CoV-2 infection from March 1 to March 25, 2020. We extracted data from electronic health records. The primary outcome was the need to mechanical ventilation at day 14. We used multivariate logistic regression to identify risk factors for mechanical ventilation. Follow-up was of at least 14 days. Results200 patients were included, of whom 37 (18{middle dot}5%) needed mechanical ventilation at 14 days. The median time from symptoms onset to mechanical ventilation was 9{middle dot}5 days (IQR 7.00, 12.75). Multivariable regression showed increased odds of mechanical ventilation in males (3.26, 1.21-9.8; p=0.025), in patients who presented with a qSOFA score [≥]2 (6.02, 2.09-18.82; p=0.001), with bilateral infiltrate (5.75, 1.91-21.06; p=0.004) or with a CRP of 40 mg/l or greater (4.73, 1.51-18.58; p=0.013). ConclusionsThis study gives some insight in the epidemiology and clinical course of patients admitted in a European tertiary hospital with SARS-CoV-2 infection. Male sex, high qSOFA score, CRP of 40 mg/l or greater and a bilateral radiological infiltrate could help clinicians identify patients at high risk for mechanical ventilation.