COVID-19 infection and 2-year mortality in nursing home residents who survived the first wave of the pandemic (preprint)

Background During the first COVID-19 pandemic wave (1stCoPW), nursing homes (NHs) experienced a high rate of COVID-19 infection and death. Residents who survived the COVID-19 infection may have become frailer. This study aimed to determine the predictive value of having a COVID-19 infection during the 1st CoPW for 2-year mortality in NH residents.Methods This was a retrospective study conducted in three NHs. Residents who had survived the 1st CoPW (March to May 2020) were included. The diagnosis of COVID-19 was based on the results of a positive reverse transcriptase-polymerase chain reaction test. The collected data also included age, sex, length of residence in the NH, disability status, legal guardianship status, nutritional status, need for texture-modified food and hospitalization during lockdown. Nonadjusted and adjusted Cox models were used to analyse factors associated with 2-year post-1st CoPW mortality.Results Among the 315 CoPW1 survivors (72% female, mean age 88 years, 48% with severe disability), 35% presented with COVID-19. Having a history of COVID-19 was not associated with 2-year mortality: hazard ratio (HR) [95% confidence interval] = 0.96 [0.81–1.13], p = 0.62. The factors independently associated with 2-year mortality were older age (for each additional year, HR = 1.05 [1.03–1.08], p < 0.01), severe disability vs moderate or no disability (HR = 1.35 [1.12–1.63], p < 0.01) and severe malnutrition vs no malnutrition (HR = 1.29 [1.04–1.60], p = 0.02).Conclusions Having survived a COVID-19 infection during the 1st CoPW did not affect subsequent 2-year survival in older adults living in NHs, suggesting that most of these residents recovered from the infection without COVID-19-related life-threatening sequelae.

Cellular Immunity of SARS-CoV-2 in the Borriana COVID-19 Cohort: A Nested Case-Control Study (preprint)

Our goal was to determine the cellular immune response (CIR) among a random sample of the Borriana COVID-19 cohort (Spain) to identify its associated factors and their relationship with infection, reinfection and sequelae. We conducted a nested case-control study using a randomly selected sample of 225 individuals age 18 and older, including 36 individual naïve to SARS-CoV-2 infection, and 189 infected patients. We employed flow cytometry-based immunoassays for intracellular cytokine staining, utilizing Wuhan and BA.2 antigens and chemoluminescence microparticle immunoassay for detection SARS-CoV-2 antibodies. Logistic regression models were used. A total of 215 (95.6%) participants exhibited T-cell response (TCR) to at least one antigen. Positive responses of CD4+ and CD8+ T cells were 89.8% and 85.3% respectively. No difference in CIR was found for naïve and infected patients. Patients who experienced sequelae exhibited higher CIR than those without. A positive correlation was observed between TCR and Anti-Spike IgG levels. Factors positive associated with TCR included A-blood group, number of SARS-CoV-2 vaccine doses received, and Anti-N IgM; factors inversely related were the time elapsed since the last vaccine dose or infection, and B-blood group. These findings contribute valuable insights into the nuance immune landscape shaped by SARS-CoV-2 infection and vaccination.

Genomic surveillance reveals dynamic shifts in the connectivity of COVID-19 epidemics (preprint)

The maturation of genomic surveillance in the past decade has enabled tracking of the emergence and spread of epidemics at an unprecedented level. During the COVID-19 pandemic, for example, genomic data revealed that local epidemics varied considerably in the frequency of SARS-CoV-2 lineage importation and persistence, likely due to a combination of COVID-19 restrictions and changing connectivity. Here, we show that local COVID-19 epidemics are driven by regional transmission, including across international boundaries, but can become increasingly connected to distant locations following the relaxation of public health interventions. By integrating genomic, mobility, and epidemiological data, we find abundant transmission occurring between both adjacent and distant locations, supported by dynamic mobility patterns. We find that changing connectivity significantly influences local COVID-19 incidence. Our findings demonstrate a complex meaning of 'local' when investigating connected epidemics and emphasize the importance of collaborative interventions for pandemic prevention and mitigation.

Inter-rater Variability in the Evaluation of Lung Ultrasound on Videos Acquired from COVID-19 Patients (preprint)

Lung ultrasound (LUS) allows the detection of a series of manifestations of COVID-19 such as B lines and consolidations. The objective of this work was to study the inter-rater reliability (IRR) when detecting signs associated with COVID-19 in the LUS, as well as the impact of performing the test in the longitudinal or transverse orientation. 33 physicians with advanced experience in LUS, independently evaluated ultrasound videos previously acquired with the ULTRACOV system of 20 patients with confirmed COVID-19. In each patient, 24 videos of 3 seconds were acquired (using 12 positions with the probe in longitudinal and transverse orientations). Physicians had no information about the patients or other previous evaluations. The score assigned to each acquisition followed the convention applied in previous studies. A substantial IRR was found in the cases of normal LUS (κ = 0.74), only a fair IRR for the presence of individual B lines (κ = 0.36) and for confluent B lines occupying <50% (κ = 0.26), and a moderate IRR in consolidations and B-lines >50% (κ = 0.50). No statistically significant differences between the longitudinal and transverse scans were found. The IRR in LUS of COVID-19 patients may benefit from more standardization of the clinical protocols.

D dimer concentration variation as predictor of mortality in patients with COVID-19.

OBJECTIVE: To evaluate the D dimer levels after the admission of patients with COVID-19 and to stablish cut-off points that are associated with more complications. MATERIALS AND METHODS: Prospective study with inpatients with severity criteria that compared the D dimer levels at admission and 48 hours later;mean D dimer concentrations were evaluated and cut-off points were stablished. RESULTS: Considering D dimer 48 hours after admission, patients that did not survive had mean levels of 5380 ng/mL versus 1811.3 ng/mL among those that survived (p < 0.005);a cut-off point of 1725 ng/mL was stablished that predicted mortality with sensitivity of 85.7%, specificity of 63%, and negative predictive value of 89.4%. In the group of patients that required invasive mechanical ventilation, mean D dimer was 4672.2 ng/mL versus 1652.6 ng/mL in those who did not need it (p < 0.001) and a cut-off point of 1770 ng/mL was calculated which predicted invasive mechanical ventilation with sensitivity of 84.6%, specificity of 63%, and negative predictive value of 89.4%. CONCLUSIONS: D dimer concentrations after 48 hours of admission can discard the development of complications, so its determination may be useful for determining the adverse evolution risk. (English) [ FROM AUTHOR] OBJETIVO: Evaluar las concentraciones de dímero D posteriores al ingreso de pacientes con COVID-19 y estipular puntos de corte que se asocien con complicaciones. MATERIALES Y MÉTODOS: Estudio prospectivo efectuado en pacientes hospitalizados con criterios de severidad que comparó las concentraciones de dímero D al ingreso y a las 48 horas;se compararon las medias de dímero D y se estipularon puntos de corte. RESULTADOS: Respecto al dímero D a las 48 horas, los pacientes que fallecieron tuvieron una media de 5380 ng/mL, a diferencia de los que no con 1811.3 ng/mL (p < 0.005);se estableció un punto de corte de 1725 ng/mL para predecir mortalidad con sensibilidad del 85.7%, especificidad del 63% y valor predictivo negativo del 89.4%. La media de dímero D de los que requirieron ventilación mecánica invasiva fue de 4672.2 ng/mL contra 1652.6 ng/mL (p < 0.001) y el punto de corte de 1770 ng/mL predice ventilación mecánica invasiva con sensibilidad del 84.6%, especificidad del 63% y valor predictivo negativo del 89.4%. CONCLUSIONES: Las concentraciones de dímero D a las 48 horas de ingreso en pacientes con COVID-19 pueden descartar la aparición de complicaciones, por lo que este marcador es útil para determinar el riesgo de evoluciones adversas. (Spanish) [ FROM AUTHOR] Copyright of Medicina Interna de Mexico is the property of Colegio de Medicina Interna de Mexico and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Atención del personal de enfermería a pacientes con esclerosis múltiple durante la pandemia de COVID-19 Nursing care of patients with multiple sclerosis during the COVID-19 pandemic

Introducción: Al comienzo de la pandemia por el virus SARS-CoV-2, los centros sanitarios fueron lugares de alto riesgo de infección y, durante el período de confinamiento, la asistencia sanitaria presencial se redujo notablemente, lo que obligó a realizar cambios rápidos en la atención a los pacientes de esclerosis múltiple por parte de la enfermería especializada en las unidades y consultas monográficas de esta enfermedad. Desarrollo: Se recoge la experiencia del personal de enfermería de las unidades y consultas monográficas de esclerosis múltiple, en ocho hospitales de España desde el comienzo de la pandemia y en etapas posteriores. Concretamente se exponen las adaptaciones que realizaron para continuar atendiendo a los pacientes durante estos períodos. También se revisa la literatura científica acerca de cómo ha afectado el SARS-CoV-2 a los pacientes con esclerosis múltiple, así como las experiencias de equipos de esclerosis múltiple en centros sanitarios de otros países. Conclusiones: Durante el confinamiento y en etapas posteriores se aplicaron formas de atención a los pacientes de esclerosis múltiple nuevas o poco empleadas con anterioridad. El personal de enfermería mantuvo el contacto con ellos por teléfono y vía telemática, proporcionando información sobre medidas de seguridad y protección frente a la infección por SARS-CoV-2, adaptando las visitas presenciales, los tratamientos y la distribución de la medicación, facilitando información para que los pacientes pudieran recibir apoyo psicosocial y sobre cómo mantener su calidad de vida.

Atención del personal de enfermería a pacientes con esclerosis múltiple durante la pandemia de COVID-19

Resumen Introducción: Al comienzo de la pandemia por el virus SARS-CoV-2, los centros sanitarios fueron lugares de alto riesgo de infección y, durante el período de confinamiento, la asistencia sanitaria presencial se redujo notablemente, lo que obligó a realizar cambios rápidos en la atención a los pacientes de esclerosis múltiple por parte de la enfermería especializada en las unidades y consultas monográficas de esta enfermedad. Desarrollo: Se recoge la experiencia del personal de enfermería de las unidades y consultas monográficas de esclerosis múltiple, en ocho hospitales de España desde el comienzo de la pandemia y en etapas posteriores. Concretamente se exponen las adaptaciones que realizaron para continuar atendiendo a los pacientes durante estos períodos. También se revisa la literatura científica acerca de cómo ha afectado el SARS-CoV-2 a los pacientes con esclerosis múltiple, así como las experiencias de equipos de esclerosis múltiple en centros sanitarios de otros países. Conclusiones: Durante el confinamiento y en etapas posteriores se aplicaron formas de atención a los pacientes de esclerosis múltiple nuevas o poco empleadas con anterioridad. El personal de enfermería mantuvo el contacto con ellos por teléfono y vía telemática, proporcionando información sobre medidas de seguridad y protección frente a la infección por SARS-CoV-2, adaptando las visitas presenciales, los tratamientos y la distribución de la medicación, facilitando información para que los pacientes pudieran recibir apoyo psicosocial y sobre cómo mantener su calidad de vida. Introduction: At the beginning of the SARS-CoV-2 pandemic, health centres were places where there was a high risk of infection, and during the period of lockdown face-to-face health care was substantially reduced, forcing rapid changes in the care of multiple sclerosis patients by the specialised nursing staff in the units and monographic consultations of this disease. Development: The experience of the nursing staff of multiple sclerosis units and monographic consultations, in eight Spanish hospitals, is collected from the beginning of the pandemic and in later stages, and the adaptations that they made to continue caring for patients are specifically described. The scientific literature about how the SARS-CoV-2 has affected patients with multiple sclerosis is also reviewed, as well as the experiences of other multiple sclerosis teams in health centres in other countries. Conclusions: During the lockdown and in later stages, new forms and previously little used forms of care were applied to multiple sclerosis patients. The nursing staff kept contact with them by telephone and online, provided them with information about safety and behaviour in relation to COVID-19. Face-to-face visits, treatments and distribution of medication were adapted. Information was provided about how patients could receive psychosocial support and about how they could maintain their quality of life.

Determining the Learning Profile of Engineering Projects Students from Their Characteristic Motivational Profile

Engineering courses usually have a low success rate, and students that take them often consider them difficult and show little motivation towards them. In this context, it is essential to obtain information about the profile of the students so that the teaching can be adapted to their perceived needs and motivations as well to provide support to them. This descriptive-exploratory research study was carried out to determine the learning profile of engineering project students through their motivational profile based on five grouping variables (gender, type of high school of origin, access studies, specialty, repeater). The instrument used was a consolidated motivational assessment questionnaire consisting of items in a series of seven basic scales aligned and grouped together into three motivational dimensions (MAPE-3). As a result, a student profile was observed that was dominated by the dimension of motivation towards the task and characterized by a mixed reflective-practical learning profile based on analytical and predominantly practical individuals.

Persistence of Anti-SARS-CoV-2 Antibodies Six Months After Infection in an Outbreak With Five Hundred COVID-19 Cases in Borriana (Spain): A Prospective Cohort Study (preprint)

In March 2020, several mass gathering events were related to the Falles festival in Borriana (Spain), resulting in a 536 laboratory-confirmed COVID-19 cases outbreak among participants. Our objective was to estimate anti-SARS-CoV-2 antibodies persistence six months after and factors associated with antibody response. A prospective population-based cohort study was carried out by the Public Health Center of Castellon and the Emergency and Clinical Analysis and Microbiology Services of Hospital de la Plana in Vila-real. In October 2020, sero-epidemiologic study to estimate the persistence of anti-SARS-CoV-2 antibodies by a electrochemiluminescence immunoassay (ECLIA) was implemented. We enrolled 484 (90.2%) of the 536 members of the initial outbreak cohort and detected persistent antibodies in 479 (99%) without re-infection episodes. Five participants had a negative antibody test. Factors associated with a negative result were a lower body mass index (BMI), and less contact with other COVID-19 cases. Among the 469 participants with two ECLIA tests, 96 (20.5%) had an increase of antibodies and 373 (79.5%) a decline. Increased antibodies were associated with older age, higher BMI, more severe illness, and low current smokers. After a COVID-19 infection, a high proportion of cases maintained detectable anti-SARS-CoV-2 antibodies.

Potential Use of Pregnancy-associated Plasma Protein-A and IMA as Biomarkers for the Early Stage of COVID-19 (preprint)

Background: This study has been undertaken with the urgent need for exploring reliable biomarkers for early infection of SARS-CoV-2. We performed a retrospective study analyzing the serum levels of the cardiovascular biomarkers N-terminal pro-B natriuretic peptide (NT-proBNP), cardiac troponin T (cTnT), Ischemia Modified Albumin (IMA) and pregnancy associated plasma protein A (PAPP-A), in 84 patients with COVID-19. Methods: Patients were divided in three groups according to their RT-qPCR and IgG values in acute infection (n=35), early infection (n=25) or control subjects (n=24). Levels of biomarkers were analyzed in patient’s serum samples by commercially available ELISA kits. Results: Multivariate analysis and Receiver Operating Characteristic (ROC) curve showed that IMA and PAPP-A, had an excellent discrimination value for the early stage of COVID-19. Serum levels of IMA in early SARS-CoV-2 infected patients were significantly higher than in the control group with an area under the ROC curve (AUC) value of 0.94 (95% confidence interval (CI): 0.881- 0.999). Likewise, the serum level of PAPP-A was significantly higher in patients with early infection than in controls [AUC = 0.801 (95% CI: 0.673–0.929)]. The combined use of IMA and PAPP-A enhanced the sensitivity for total SARS-CoV-2 infected patients to 93%. Conclusions: These results suggest that the levels of PAPP-A and IMA might be used as efficient biomarkers for the early stage of COVID-19 with high sensitivity and specificity. Importantly, when monitoring pregnancy and cardiovascular diseases by PAPP-A or IMA levels, an infection by SARS-CoV-2 should be discarded for proper interpretation of the results.

VERIFICACIÓN INFORMATIVA DURANTE LA COVID-19. ANÁLISIS COMPARATIVO EN LOS PAÍSES DEL SUR DE EUROPA

La desinformación implica un reto para las democracias especialmente en periodos excepcionales como procesos electorales pero, sobre todo, como consecuencia de una crisis sanitaria de carácter global y sin fecha de finalización clara. El objetivo de esta investigación se centra en analizar el tipo de bulos identificados durante la pandemia de COVID-19 en los países del sur de Europa (Portugal, España, Italia y Grecia). Para ello se analizarán 936 desinformaciones reportadas por las principales organizaciones de verificación en esos países: Observador y Poligrafo (Portugal), Newtral, Maldita y EFE verifica (España) Facta, Open, Effecinque y Pagella Politica (Italia) y Ellinika Hoaxes (Grecia) entre los meses de febrero y agosto de 2020. Como conclusión final se indaga en la presencia o ausencia de un patrón común en los cuatro países a partir de la temática de los bulos, sus canales de distribución y la viralización en el extranjero estableciéndose dos ejes de desinformación: uno sanitariopreventivo y otro político-polarizado. (Spanish) [ABSTRACT FROM AUTHOR] Copyright of Janus.Net: e-Journal of International Relations is the property of Universidade Autonoma de Lisboa, Observare / Observatorio de Relacoes Exteriores and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Situación de la cirugía laparoscópica y robótica urológica durante la pandemia COVID-19

OBJETIVO: La pandemia provocada por el nuevo coronavirus SARS-CoV-2 ha tenido una elevada repercusión sobre la cirugía mínimamente invasiva (CMI). Ha surgido una importante controversia sobre la realización de CMI durante la pandemia COVID-19. Es prioritario, establecer un consenso sobre la organización y realización con seguridad de la CMI durante la pandemia. MATERIAL Y MÉTODOS: Se realizó una búsqueda web y en PubMed con los términos: "SARS-CoV-2", "COVID19", "COVID19 Urology", "COVID19 Surgery", "COVID19 transmission", "SARS-CoV-2 transmission", "COVID19 and minimally invasive surgery", "SARSCoV-2 and CO2 insuflation". Se realizó una revisión narrativa de la literatura y una síntesis de la evidencia disponible. Se ha utilizado una técnica de grupo nominal modificada, circulando un primer borrador a todos los autores y aprobándose la versión definitiva el día 26 de Mayo de 2020. RESULTADOS: No existe evidencia sobre una mayor exposición a SARS-CoV-2 en CMI respecto a cirugía abierta. La CMI se asocia a una menor estancia hospitalaria por lo que cambiar, sin justificación, la indicaciónde CMI puede retrotraer recursos que podrían ser utilizados para la pandemia COVID-19. Se debe priorizar la CMI según los recursos disponibles y la intensidad de la pandemia en cada momento. Se recomienda realizar despistaje de SARS-CoV-2 mediante cuestionario clínico-epidemiológico y PCR nasofaríngea 72 horas antes de la CMI electiva, para minimizar las complicaciones postoperatorias, evitar la transmisión cruzada entre pacientes y la posible exposición de los profesionales sanitarios. Se recomienda establecer medidas de organización en quirófano, de protección personal, técnica quirúrgica y manejo del CO2 y aerosoles generados para reducir la exposición y riesgos del personal sanitario. CONCLUSIONES: La CMI realizada con las medidasd e seguridad adecuadas para el paciente y profesionales, puede contribuir durante la desescalada a una menor utilización de recursos sanitarios y por tanto, no debe limitarse su utilización o cambiar sus indicaciones OBJECTIVE: SARS-CoV-2 pandemic has high repercussion on urologic minimally invasive surgery (MIS). Controversy about safety of MIS procedures during COVID-19 pandemic has been published. Nowadays, our priority should be create agreement in order to restart and organize MIS with safety conditions for patients and healthcare workers. METHODS: Pubmed and web search was conducted with following terms: "SARS-CoV-2", "COVID19";"COVID19 Urology", COVID19 Surgery", "COVID19 transmission", "SARS-CoV-2 transmission", "COVID19 and minimally invasive surgery""SARS-CoV-2 and CO2 insuflation". A narrative review of available literature and scientific evidence summary was done. A modify nominal group technique was used to achieve an expert consensus. First draft was circulated amongst authors. Definitive document was approved in May 26th. RESULTS: Non evidence supports higher risk of SARSCoV-2 healthcare workers infection with MIS compared to open surgery. MIS is associated with shorter hospital stay than open surgery. Modify MIS indications to open surgery, with no scientific evidence, could spend valuable resources in detriment to COVID-19 patients. MIS indications should be prioritized attending to available resources and pandemic intensity. SARS-CoV-2 screening 72 hours prior to surgery by clinical and epidemiological questionnaire and nasopharyngeal PCR is recommended, in order to prevent nosocomial transmission, professional infections and to minimize postoperative complications. Intraoperative steps should be established to reduce professional exposure to surgical aerosols, including: surgical room reorganization, adequate personal protective equipment, surgical technique optimization and management of CO2 and surgical smoke

Performance of saliva specimens for the molecular detection of SARS-CoV-2 in the community setting: does sample collection method matter? (preprint)

BackgroundData on the performance of saliva specimens for diagnosing COVID-19 in ambulatory patients are scarce and inconsistent. We assessed saliva-based specimens for detecting SARS-CoV-2 by RT-PCR in the community setting and compared three different collection methods. MethodProspective study conducted in three primary care centres. RT-PCR was performed in paired nasopharyngeal swabs (NPS) and saliva samples collected from outpatients with a broad clinical spectrum of illness. To assess differences in collection methods, saliva specimens were obtained in a different way in each of the participating centres: supervised collection (SVC), oropharyngeal washing (OPW) and self-collection (SC). ResultsNPS and saliva pairs of samples from 577 patients (median age 39 years, 44% men, 42% asymptomatic) were collected and tested, and 120 (20.8%) gave positive results. The overall agreement with NPS and kappa coefficients (K) for SVC, OPW and SC were 95% (=0.85), 93.4% (=0.76), and 93.3% (=0.76), respectively. The sensitivity (95% CI) of the saliva specimens varied from 86% (72.6-93.7) for SVC to 66.7% (50.4-80) for SC samples. The sensitivity was higher in samples with lower cycle threshold (Ct) values. The best performance of RT-PCR was observed for SVC, with sensitivity (95% CI) for Ct values [≤]32 of 97% (82.5-99.8) in symptomatic, and 88.9% (50.7-99.4) in asymptomatic individuals. ConclusionsSaliva is an acceptable specimen for the detection of SARS-CoV-2 in the community setting. Specimens collected under supervision perform comparably to NPS and can effectively identify individuals with higher risk of transmission in real life conditions.

Nasopharyngeal Panbio COVID-19 antigen performed at point-of-care has a high sensitivity in symptomatic and asymptomatic patients with higher risk for transmission and older age (preprint)

BackgroundPerformance of point-of-care tests in clinical practice remains undetermined. We aimed to evaluate the performance of the nasopharyngeal Panbio COVID-19 antigen Rapid Test Device in real-life conditions in different clinical scenarios. MethodProspective study conducted in three primary care centers (PCC) and an emergency department. The antigen test was performed at point-of-care in nasopharyngeal and nasal swabs, and in saliva. Positive and negative percent agreement (PPA, NPA) were calculated with the RT-PCR assay as reference standard. ResultsOf 913 patients included, 296 (32.3%) were asymptomatic and 690 (75.6%) came from the PCC. Nasopharyngeal swabs were collected from 913, nasal swabs from 659, and saliva from 611 patients. RT-PCR was positive in 196 (21.5%) nasopharyngeal samples (NPS). Overall PPA (95% CI) in NPS was 60.5% (53.3-67.4), and it was lower in nasal swabs (44.7%) and saliva (23.1%). Test performance in NPS was largely dependent on the cycle threshold (Ct) in RT-PCR, with PPA>90% for Ct[≤]25 and [≥]80% for Ct<30. In symptomatic patients, the PPA was 95% for Ct[≤]25; [≥]85% for Ct<30, and 89% for the symptom triad of fever, cough and malaise. Performance was also dependent on age, with PPA of 100% in symptomatic patients >50 years with Ct<25. In asymptomatic patients, the PPA was 86% for Ct<25. In all cases, NPA was 100%. ConclusionThe nasopharyngeal Panbio COVID-19 antigen test performed at point-of-care is highly sensitive in symptomatic patients, particularly with Ct<30 and older age. The test was useful to identify asymptomatic patients with lower Ct values and therefore with contagious risk. Key pointsThe nasopharyngeal Panbio-COVID-19 antigen test performed in real-life conditions at point-of-care is highly sensitive in symptomatic patients, particularly with Ct<30 and older age. The test is useful to identify asymptomatic patients with lower Ct values and therefore with contagious risk.

Sample Pooling as an efficient strategy for SARS-COV-2 RT-PCR screening: a multicenter study in Spain (preprint)

Importance: The actual demand on SARS-CoV-2 diagnosis is a current challenge for clinical laboratories. Sample pooling may help to ameliorate workload in clinical laboratories. Objective: to evaluate the efficacy of sample pooling compared to the individual analysis for the diagnosis of CoVID-19, by using different commercial platforms for nucleic acid extraction and amplification. Design and settings: observational, prospective, multicentre study across 9 Spanish clinical microbiology laboratories including SARS-CoV-2 RNA testing performed in April 2020, during the first three days after acceptance to participate. Participants and Methods: 3519 naso-oro-pharyngeal samples received at the participating laboratories were processed individually and in pools (351 pools) according to the existing methodology in each of the centres. Results: We found that 253 pools (2519 samples) were negative, and 99 pools (990 samples) were positive; with 241 positive samples (6.85%), our pooling strategy would have saved 2167 PCR tests. For 29 pools (made out of 290 samples) we found discordant results when compared to their correspondent individual samples: in 24/29 pools (30 samples), minor discordances were found; for five pools (5 samples), we found major discordances. Sensitivity, specificity, positive and negative predictive values for pooling were 97.93%, 100%, 100% and 99.85% respectively; accuracy was 99.86% and kappa concordant coefficient was 0.988. As a result of the sample dilution effect of pooling, a loss of 2-3 Cts was observed for E, N or RdRP genes. Conclusion: we show a high efficiency of pooling strategies for SARS-CoV-2 RNA testing, across different RNA extraction and amplification platforms, with excellent performance in terms of sensitivity, specificity, and positive and negative predictive values. We believe that our results may help clinical laboratories to respond to the actual demand and clinical need on SARS-CoV-2 testing, especially for the screening of low prevalence populations.

Infodemia and COVID-19. Evolution and viralization of false information in Spain

Introduction: Verifying information is a democratic challenge, especially in periods of exceptionality and crisis. Objective: To analyze the type of hoaxes identified during the COVID-19 pandemic according to their topic, verification date, distribution channels, viralization in other countries and identification of their promoters. Methodology: 166 hoaxes reported by the organization Maldita.es to the collaborative verification platform LatamChequea from February 14 to April 15, 2020 have been analyzed. Results: Among the main results, we draw attention to the high presence of misinformation around infections and preventive measures. Conclusions: Misinformation and disinformation increases as the pandemic sets in and a series of containment measures are taken, we hightlight the viralization of hoaxes through social networks and instant messaging services, in addition to its international reach and the high difficulty in identifying its promoters.