ABSTRACT
The novel coronavirus disease (COVID-19) forced rapid adaptations in the way healthcare is delivered and coordinated by health systems. Brazil has a universal public health system (Sistema Unico de Saúde-SUS), being the main source of care for 75% of the population. Therefore, a saturation of the system was foreseen with the continuous increase of cases. The use of Artificial Intelligence (AI) to empower telehealth could help to tackle this by increasing a coordinated patient access to the health system. In the present study we describe a descriptive case report analyzing the use of Laura Digital Emergency Room-an AI-powered telehealth platform-in three different cities. It was computed around 130,000 interactions made by the chatbot and 24,162 patients completed the digital triage. Almost half (44.8%) of the patients were classified as having mild symptoms, 33.6% were classified as moderate and only 14.2% were classified as severe. The implementation of an AI-powered telehealth to increase accessibility while maintaining safety and leveraging value amid the unprecedent impact of the COVID-19 pandemic was feasible in Brazil and may reduce healthcare overload. New efforts to yield sustainability of affordable and scalable solutions are needed to truly leverage value in health care systems, particularly in the context of middle-low-income countries.
ABSTRACT
Serological assays are important tools to identify previous exposure to SARS-CoV-2, helping to track COVID-19 cases and determine the level of humoral response to SARS-CoV-2 infections and/or immunization to future vaccines. Here, the SARS-CoV-2 nucleocapsid protein was expressed in Escherichia coli and purified to homogeneity and high yield using a single chromatography step. The purified SARS-CoV-2 nucleocapsid protein was used to develop an indirect enzyme-linked immunosorbent assay for the identification of human SARS-CoV-2 seroconverts. The assay sensitivity and specificity were determined analyzing sera from 140 RT-qPCR-confirmed COVID-19 cases and 210 pre-pandemic controls. The assay operated with 90% sensitivity and 98% specificity; identical accuracies were obtained in head-to-head comparison with a commercial ELISA kit. Antigen-coated plates were stable for up to 3 months at 4 °C. The ELISA method described is ready for mass production and will be an additional tool to track COVID-19 cases.
Subject(s)
COVID-19 , Coronavirus Nucleocapsid Proteins/immunology , Enzyme-Linked Immunosorbent Assay , Seroconversion , Antibodies, Viral/blood , COVID-19/diagnosis , COVID-19/immunology , Humans , Immunity, Humoral , Nucleocapsid Proteins/genetics , Phosphoproteins/immunology , Sensitivity and SpecificityABSTRACT
Immunological methods to detect SARS-CoV-2 seroconversion in humans are important to track COVID-19 cases and the humoral response to SARS-CoV-2 infections and immunization to future vaccines. The aim of this work was to develop a simple chromogenic magnetic bead-based immunoassay which allows rapid, inexpensive, and quantitative detection of human antibodies against SARS-CoV-2 in serum, plasma, or blood. Recombinant 6xHis-tagged SARS-CoV-2 Nucleocapsid protein was mobilized on the surface of Ni2+ magnetic beads and challenged with serum or blood samples obtained from controls or COVID-19 cases. The beads were washed, incubated with anti-human IgG-HPR conjugate, and immersed into a solution containing a chromogenic HPR substrate. Bead transfer and homogenization between solutions was aided by a simple low-cost device. The method was validated by two independent laboratories, and the performance to detect SARS-CoV-2 seroconversion in humans was in the same range as obtained using the gold standard immunoassays ELISA and Luminex, though requiring only a fraction of consumables, instrumentation, time to deliver results, and volume of sample. Furthermore, the results obtained with the method described can be visually interpreted without compromising accuracy as demonstrated by validation at a point-of-care unit. The magnetic bead immunoassay throughput can be customized on demand and is readily adapted to be used with any other 6xHis tagged protein or peptide as antigen to track other diseases.
Subject(s)
Antibodies, Viral/blood , COVID-19 Serological Testing , COVID-19/diagnosis , Enzyme-Linked Immunosorbent Assay/methods , SARS-CoV-2/immunology , COVID-19/blood , COVID-19/immunology , Humans , Immunoglobulin G/immunology , Magnetic PhenomenaABSTRACT
This is the first case reported of central venous catheter-related fungemia due to C. neoformans. A patient with chronic renal failure developed a fungemia during the treatment of a dialysis-associated bacteremia. Cryptococcus neoformans grew in the catheter tip and blood culture. We addressed questions about this catheter-related fungemia.
Subject(s)
Female , Humans , Middle Aged , Catheter-Related Infections/microbiology , Catheterization, Central Venous/adverse effects , Cryptococcosis/microbiology , Cryptococcus neoformans/isolation & purification , Fungemia/microbiology , Amphotericin B/therapeutic use , Antifungal Agents/therapeutic use , Catheter-Related Infections/diagnosis , Catheter-Related Infections/drug therapy , Cryptococcosis/diagnosis , Cryptococcosis/drug therapy , Fatal Outcome , Fungemia/diagnosis , Fungemia/drug therapy , Kidney Failure, Chronic/therapy , Renal Dialysis/adverse effectsABSTRACT
This is the first case reported of central venous catheter-related fungemia due to C. neoformans. A patient with chronic renal failure developed a fungemia during the treatment of a dialysis-associated bacteremia. Cryptococcus neoformans grew in the catheter tip and blood culture. We addressed questions about this catheter-related fungemia.
