Prediction of SARS-CoV-2 infection with a Symptoms-Based model to aid public health decision making in Latin America and other low and middle income settings.

Symptoms-based models for predicting SARS-CoV-2 infection may improve clinical decision-making and be an alternative to resource allocation in under-resourced settings. In this study we aimed to test a model based on symptoms to predict a positive test result for SARS-CoV-2 infection during the COVID-19 pandemic using logistic regression and a machine-learning approach, in Bogotá, Colombia. Participants from the CoVIDA project were included. A logistic regression using the model was chosen based on biological plausibility and the Akaike Information criterion. Also, we performed an analysis using machine learning with random forest, support vector machine, and extreme gradient boosting. The study included 58,577 participants with a positivity rate of 5.7%. The logistic regression showed that anosmia (aOR = 7.76, 95% CI [6.19, 9.73]), fever (aOR = 4.29, 95% CI [3.07, 6.02]), headache (aOR = 3.29, 95% CI [1.78, 6.07]), dry cough (aOR = 2.96, 95% CI [2.44, 3.58]), and fatigue (aOR = 1.93, 95% CI [1.57, 2.93]) were independently associated with SARS-CoV-2 infection. Our final model had an area under the curve of 0.73. The symptoms-based model correctly identified over 85% of participants. This model can be used to prioritize resource allocation related to COVID-19 diagnosis, to decide on early isolation, and contact-tracing strategies in individuals with a high probability of infection before receiving a confirmatory test result. This strategy has public health and clinical decision-making significance in low- and middle-income settings like Latin America.

SARS-CoV-2 Drive/Walk-Thru screening centers in Colombia: The CoVIDA Project / Centros de tamizaje masivo para SARS COV-2 en Colombia: Proyecto CoVIDA

Abstract Objective: The CoVIDA project is a public-private collaboration led by Universidad de los Andes that contributed to the SARS-CoV-2 epidemiological surveillance in Bogotá and nearby municipalities. We aimed to describe the development and performance of the Drive/Walk-through free RT- PCR for SARS-CoV-2 testing strategy implemented by CoVIDA. Material and method: We performed a descriptive analysis of the characteristics and performance of the CoVIDA Drive/Walk-through testing centers. The model and the process indicators to assess the model's performance were based on international experiences and scientific literature. Two screening centers were imple mented in shopping centers in the north and south of Bogotá. We reported the number of tests taken, the number of positive tests, and the number of participants that used the model by the type of occupations. Results: In total, 36,689 nasopharyngeal RT-PCR tests for SARS-CoV-2 were performed with a 5.75% cumulative positivity. Process indicators showed an excellent performance and an important contribution in reducing barriers to access to testing. Conclusions: the CoVIDA Drive/Walk-through testing centers supported the epidemiological surveillance in asymptomatic or mild-symptomatic population in Bo gotá. Low and middle-income countries can use this model as a cost-effective and innovative solution strategy to intensify testing and help mitigate the pandemic.

Resumen Objetivo: El proyecto CoVIDA es una colaboración público-privada liderada por la Universidad de los Andes que contribuyó a la vigilancia epidemiológica del SARS-CoV-2 en Bogotá y municipios cercanos. Nuestro objetivo fue describir el desarrollo y rendimiento de la estrategia de tamizaje gratuito con RT-PCR mediante un modelo Drive/Walk through para SARS-CoV-2 implementado por CoVIDA. Materiales y métodos: Realizamos un análisis descriptivo de las características y desempeño de los centros de tamizaje Drive/Walk through de CoVIDA. El modelo y los indicadores de proceso para evaluar el desempeño del modelo se basaron en experiencias internacionales y la literatura científica. Se implementaron dos cen tros de tamizaje en centros comerciales del norte y sur de Bogotá. Se reportó la cantidad de pruebas tomadas, pruebas positivas y de participantes que utilizaron el modelo de acuerdo con el tipo de ocupaciones. Resultados : En total, se realizaron 36,689 pruebas RT-PCR nasofaríngeas para SARS-CoV-2 con una positividad acumulada del 5,75%. Los indicadores de proceso mostraron un excelente desempeño y una contribución importante en la reducción de las barreras de acceso a las pruebas. Conclusiones: los centros de tamizaje con modelo Drive/Walk through de CoVIDA apoyaron la vigilancia epidemiológica en población asintomática o con síntomas leves en Bogotá. Los países de ingresos bajos y medianos pueden utilizar este modelo como una estrategia innovadora y rentable para aumentar la realización de las pruebas y ayudar a mitigar la pandemia.

Seborrheic dermatitis and its relationship with Malassezia spp / Dermatitis seborreica y su relación con Malassezia spp

Abstract Seborrheic dermatitis (SD) is a chronic inflammatory disease that that is difficult to manage and with a high impact on the individual's quality of life. Besides, it is a multifactorial entity that typically occurs as an inflammatory response to Malassezia species, along with specific triggers that contribute to its pathophysiology. Sin ce the primary underlying pathogenic mechanisms include Malassezia proliferation and skin inflammation, the most common treatment includes topical antifungal keratolytics and anti-inflammatory agents. However, the consequences of eliminating the yeast population from the skin, the resistance profiles of Malassezia spp. and the effectivity among different groups of medications are unknown. Thus, in this review, we summarize the current knowledge on the disease´s pathophysio logy and the role of Malassezia sp. on it, as well as, the different antifungal treatment alternatives, including topical and oral treatment in the management of SD.

Resumen La dermatitis seborreica (DS) es una enfermedad inflamatoria crónica, con un elevado impacto en la calidad de vida del individuo. Además, DS es una entidad multifactorial que ocurre como respuesta inflamatoria a las levaduras del género Malassezia spp., junto con factores desencadenantes que contribuyen a la fisio patología de la enfermedad. Dado que el mecanismo patogénico principal involucra la proliferación e inflamación generada por Malassezia spp., el tratamiento más usado son los agentes tópicos antifúngicos y antiinflamatorios. Sin embargo, se desconocen las consecuencias de eliminar la población de levaduras de la piel, los perfiles de resistencia de Malassezia spp. y la efectividad entre grupos diferentes de medicamentos. Por tanto, en esta revisión de la literatura, resumimos el conocimiento actual sobre la fisiopatología de la enfermedad y el papel de Malassezia sp., así como de las diferentes alternativas de tratamiento antifúngico tanto tópico como oral en el manejo de la DS.

Assembly and Analysis of Differential Transcriptome Responses of Hevea brasiliensis on Interaction with Microcyclus ulei.

Natural rubber (Hevea brasiliensis) is a tropical tree used commercially for the production of latex, from which 40,000 products are generated. The fungus Microcyclus ulei infects this tree, causing South American leaf blight (SALB) disease. This disease causes developmental delays and significant crop losses, thereby decreasing the production of latex. Currently several groups are working on obtaining clones of rubber tree with durable resistance to SALB through the use of extensive molecular biology techniques. In this study, we used a secondary clone that was resistant to M. ulei isolate GCL012. This clone, FX 3864 was obtained by crossing between clones PB 86 and B 38 (H. brasiliensis x H. brasiliensis). RNA-Seq high-throughput sequencing technology was used to analyze the differential expression of the FX 3864 clone transcriptome at 0 and 48 h post infection (hpi) with the M. ulei isolate GCL012. A total of 158,134,220 reads were assembled using the de novo assembly strategy to generate 90,775 contigs with an N50 of 1672. Using a reference-based assembly, 76,278 contigs were generated with an N50 of 1324. We identified 86 differentially expressed genes associated with the defense response of FX 3864 to GCL012. Seven putative genes members of the AP2/ERF ethylene (ET)-dependent superfamily were found to be down-regulated. An increase in salicylic acid (SA) was associated with the up-regulation of three genes involved in cell wall synthesis and remodeling, as well as in the down-regulation of the putative gene CPR5. The defense response of FX 3864 against the GCL012 isolate was associated with the antagonistic SA, ET and jasmonic acid (JA) pathways. These responses are characteristic of plant resistance to biotrophic pathogens.