Outbreak report of SARS-CoV-2 infection by airborne transmission: Epidemiologic and molecular evidence. / Reporte de un brote de infección por SARS-CoV-2 por transmisión aérea: evidencia epidemiológica y molecular

INTRODUCTION: It has been shown that the transmission of SARS-CoV-2 occurs mainly by air, and the risk of infection is greater in closed spaces. OBJECTIVE: To describe the epidemiology, virology and molecular characterization of a COVID-19 outbreak at a closed vaccination point during the third wave of SARS-CoV-2 in Colombia. MATERIALS AND METHODS: Diagnostic tests, interviews, sampling, cell cultures and viral sequencing were carried out, the latter being molecular characterization and lineage identification. RESULTS: Seven workers were positive for SARS-CoV-2; among these, 3 samples were analyzed, plus an additional sample belonging to the mother of the presumed index case; all samples were identified with lineage B.1.625, with a maximum of 2 nucleotides difference between them. CONCLUSIONS: Variant B.1.625 was identified as the cause of the COVID-19 outbreak, and a co-worker was also identified as the index case. Unexpectedly, attending a vaccination day became a risk factor for acquiring the infection.

Introducción. Se ha demostrado que la transmisión de SARS-CoV-2 se produce principalmente por vía aérea y el riesgo de infección es mayor en espacios cerrados con alta concentración de personas; este último factor se presentó en algunos de los puestos de vacunación de la ciudad de Medellín. Objetivo. Describir la epidemiología, virología y caracterización molecular de un brote de COVID-19 en un punto de vacunación cerrado durante la tercera ola de SARS-CoV-2 en Colombia. Materiales y métodos. Se realizaron test diagnósticos, entrevistas, toma de muestras, aislamiento viral y secuenciación genómica. Con esta última, se hizo la caracterización molecular y se identificó el linaje. Resultados. Siete trabajadores fueron positivos para SARS-CoV-2, y de estos, tres muestras fueron secuenciadas, más una muestra adicional perteneciente a la madre del presunto caso índice. Todas las muestras fueron identificadas con el linaje B.1.625, con un máximo de dos nucleótidos de diferencia entre ellas. Conclusiones. Se identificó la variante B.1.625 como la causante del brote de COVID-19, y también un compañero de trabajo fue identificado como el caso índice. De forma imprevista, asistir a una jornada de vacunación se convirtió en un factor de riesgo para adquirir la infección.

SARS-CoV-2 electrochemical immunosensor based on the spike-ACE2 complex.

Rapid, straightforward, and massive diagnosis of coronavirus disease 2019 (COVID-19) is one of the more important measures to mitigate the current pandemics. This work reports on an immunosensor to rapidly detect the spike protein from the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The immunosensing device entraps the spike protein linked to angiotensin-converting enzyme host receptor (ACE2) protein in a sandwich between carboxylated magnetic beads functionalized with an anti-spike antibody and an anti-ACE2 antibody, further labeled with streptavidin (poly)horseradish peroxidase (HRP) reporter enzyme. The particles were confined at the surface of screen-printed gold electrodes, whose signal resulting from the interaction of the enzyme with a mediator was recorded in a portable potentiostat. The immunosensor showed a sensitivity of 0.83 µA∗mL/µg and a limit of detection of 22.5 ng/mL of spike protein, with high reproducibility. As a proof-of-concept, it detected commercial spike protein-supplemented buffer solutions, pseudovirions, isolated viral particles and ten nasopharyngeal swab samples from infected patients compared to samples from three healthy individuals paving the way to detect the virus closer to the patient.

SARS-CoV-2 electrochemical immunosensor based on the spike-ACE2 complex

Rapid, straightforward, and massive diagnosis of coronavirus disease 2019 (COVID-19) is one of the more important measures to mitigate the current pandemics. This work reports on an immunosensor to rapidly detect the spike protein from the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The immunosensing device entraps the spike protein linked to angiotensin-converting enzyme host receptor (ACE2) protein in a sandwich between carboxylated magnetic beads functionalized with an anti-spike antibody and an anti-ACE2 antibody, further labeled with streptavidin (poly)horseradish peroxidase (HRP) reporter enzyme. The particles were confined at the surface of screen-printed gold electrodes, whose signal resulting from the interaction of the enzyme with a mediator was recorded in a portable potentiostat. The immunosensor showed a sensitivity of 0.83 μA*mL/μg and a limit of detection of 22.5 ng/mL of spike protein, with high reproducibility. As a proof-of-concept, it detected commercial spike protein-supplemented buffer solutions, pseudovirions, isolated viral particles and ten nasopharyngeal swab samples from infected patients compared to samples from three healthy individuals paving the way to detect the virus closer to the patient. Graphical Image 1