Aportes de la biotecnología en el diagnóstico de COVID-19 / Biotechnology contributions in COVID-19 diagnosis

Introducción: en diciembre del año 2019 surgió en China una neumonía viral; el virus fue identificado como un coronavirus SARS-CoV-2, que se propagó rápidamente de tal manera que se convirtió en pandemia. La alta contagiosidad y la presencia de portadores asintomáticos dificultaron el diagnóstico de la infección y la toma de decisiones sanitarias. Objetivo: el objetivo de esta revisión bibliográfica es presentar y describir las principales técnicas utilizadas actualmente para el diagnóstico de COVID-19 y establecer su relación con los conocimientos de distintas disciplinas y tecnologías emergentes que confluyen en la Biotecnología bioquímico-farmacéutica orientada a la Salud humana. Metodología: se realizó una revisión de la bibliografía disponible en PubMed a partir de enero de 2020 sobre las pruebas diagnósticas que se encuentran actualmente en uso, en el ámbito sanitario, para la detección y seguimiento de la enfermedad COVID-19. También se realizaron búsquedas a través de Google y Google Académico para publicaciones de organismos de Salud en referencia a métodos diagnósticos. Resultados: se presenta una importante cantidad de pruebas diagnósticas, basadas en diferentes tecnologías, que desempeñan un papel clave en la pandemia de COVID-19. Algunas de ellas muy sofisticadas, como la secuenciación genómica de próxima generación, otras más estándar, pero igualmente robustas, como la reacción en cadena de la polimerasa (PCR). También otras adaptadas para el brote pandémico, como la amplificación isotérmica de ácidos nucleicos mediada por bucle. Todas las mencionadas se consideran de tipo molecular, pero también existen las pruebas serológicas, como ELISA, que incluyen ensayos en plasma o de tipo inmunológico. Estas sirven para detectar anticuerpos frente a la exposición al virus o antígenos en personas potencialmente infectadas. Conclusiones: los procesos de investigación y desarrollo biotecnológicos aplicados al diagnóstico y los conocimientos científicos previos permitieron una respuesta tanto nacional como internacional rápida y eficaz en medio de una inédita pandemia global. En esta revisión destacamos las principales técnicas, en qué estadio se deben usar y qué información nos aportan. (AU)

Introduction: in December 2019, a viral pneumonia emerged in China, identifying the virus as a SARS-CoV-2 coronavirus, which spread rapidly in such a way that it became a pandemic. The high contagiousness and the presence of asymptomatic carriers make difficulted to diagnose the infection and to make health decisions. Target: the objective of this review is to present and describe the main techniques currently used for the diagnosis of COVID-19, and to establish their relationship with the knowledge of different disciplines and emerging technologies that converge in biochemical-pharmaceutical biotechnology oriented to human health. Methodology: a review of the literature available in Pubmed from January 2020 on the diagnostic tests that are currently in use in the health field, for the detection and monitoring of COVID-19 disease, was carried out. Searches were also carried out through Google and Google Scholar for publications of Health organizations in reference to diagnostic methods. Results: a significant number of diagnostic tests are presented, based on different technologies, which play a key role in the COVID-19 pandemic. Some of them are very sophisticated, such as next-generation genomic sequencing, others more standard, but equally robust, such as polymerase chain reaction. Also others adapted for the pandemic outbreak such as loop-mediated isothermal amplification of nucleic acids. All of the aforementioned are considered molecular, but there are also serological tests, such as ELISA, which include plasma or immunological tests. These serve to detect antibodies against exposure to the virus or antigens in potentially infected people. Conclusions: biotechnological research and development processes applied to diagnosis and previous scientific knowledge allowed a rapid and effective national and international response in the midst of an unprecedented global pandemic. In this review we highlight the main techniques, at what stage they should be used and what information they provide us. (AU)

Validación de pruebas rápidas de COVID-19. Isla de la Juventud, Cuba / COVID-19 rapid test validation. Isla de la Juventud, Cuba

Contar con métodos diagnósticos que reúnan ciertos atributos es vital para guiar las decisiones sanitarias, el contexto actual lo amerita. Con el objetivo de validar la capacidad de dos pruebas rápidas para detectar anticuerpos debido a la infección por SARS-CoV-2 en la Isla de la Juventud, Cuba, de abril a mayo de 2020, se realizó un estudio descriptivo de corte transversal de evaluación de pruebas rápidas: Wondfo (SARS-CoV-2 antibody test) y Lungene covid-19 IgG/IgM rapid test, en comparación con la prueba de reacción en cadena de la polimerasa en tiempo real. Se construyeron dos muestras homogéneas de 250 cada una, determinándose indicadores de validación. Se obtuvieron valores de sensibilidad de 6,6 por ciento y 8,3 por ciento respectivamente para cada prueba, mientras que la especificidad resultó superior para Wondfo (95 por ciento). Los valores predictivos positivos resultaron muy bajos, los negativos adecuados, superior en Lungene con el 94,8 por ciento. Los valores de razón de verosimilitud fueron clasificados como inútiles. En diferentes escenarios en cuanto a casos sintomáticos, se alcanzó sensibilidad del 50 por ciento en intervalo de 1 a 7 días para Wondfo. El área bajo la curva ROC para Wondfo fue 0,50 (IC95 por ciento=0,46-0,55) y para Lungene 0,46 (IC95 por ciento=0,38-0,55). El índice kappa para Wondfo fue de 0,025 y 0,010 para Lungene. Las pruebas rápidas exploradas mostraron muy baja sensibilidad, valor predictivo positivo y razón de verosimilitud inadecuada. La validez global de las pruebas no demostró un buen desempeño diagnóstico, marcado por el valor del área bajo la curva ROC(AU)

Having diagnostic methods that meet certain attributes is vital to guide health decisions, the current context warrants it. In order to validate the capacity of two rapid tests to detect antibodies due to SARS-CoV-2 infection in Isla de la Juventud, Cuba, from April to May 2020, a descriptive cross-sectional evaluation study was carried out. Rapid tests: Wondfo (SARS-CoV-2 antibody test) and Lungene covid-19 IgG/IgM, were compared to the real-time polymerase chain reaction test. Two homogeneous samples of 250 each were constructed, determining validation indicators. Sensitivity values of 6.6 percent and 8.3 percent respectively were obtained for each test, while the specificity was higher for Wondfo (95 percent). The positive predictive values were very low, the negative ones were adequate, higher in Lungene with 94.8 percent. Likelihood ratio values were classified as useless. In different scenarios in terms of symptomatic cases, sensitivity of 50 percent was reached in an interval of 1 to 7 days for Wondfo. The area under the ROC curve for Wondfo was 0.50 (95 percent CI = 0.46-0.55) and 0.46 for Lungene (95 percent CI = 0.38-0.55). The kappa index for Wondfo was 0.025 and 0.010 for Lungene. The rapid tests explored showed very low sensitivity, positive predictive value, and inadequate likelihood ratio. The global validity of the tests did not demonstrate a good diagnostic performance, marked by the value of the area under the ROC curve. The degree of agreement was poor(AU)

Impact of rt-pcr test false-negative results for SARS-CoV-2 surveillance in Mexico

ABSTRACT Background: Underestimation of the number of cases during the coronavirus disease 2019 (COVID-19) pandemic has been a constant concern worldwide. Detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA using real-time reverse-transcription polymerase chain reaction (RT-PCR) is the most common method to confirm a case. However, these tests have suboptimal sensitivity. Objective: The objective of the study was to estimate the number of COVID-19 confirmed cases, intensive care unit (ICU) admissions and deaths in Mexico, accounting for the probabilities of false-negative tests. Methods: We used publicly available, national databases of all SARS-CoV-2 tests performed at public laboratories in Mexico between February 27 and October 31, 2020. We used the estimated probabilities of false-negative tests based on the day of clinical sample collection after symptom initiation calculated previously. With the resulting model, we estimated the corrected daily number of cases, ICU admissions, and deaths. Results: Among 2,024,822 people tested in Mexico between February 27 and October 31 with an available result, we estimated 1,248,583 (95% confidence interval 1,094,850-1,572,818) cases, compared to 902,343 cases reported with positive tests. ICU admissions and deaths were 15% and 8% higher than reported, respectively. Conclusion: Accounting for SARS-CoV-2 RT-PCR-based diagnostic testsҠprecision is a simple way to improve estimations for the true number of COVID-19 cases among tested persons.

Comparison of laboratory and radiological findings of pregnant and non-pregnant women with covid-19

Abstract Objective Covid-19 became a pandemic, and researchers have not been able to establish a treatment algorithm. The pregnant population is also another concern for health care professionals. There are physiological changes related to pregnancy that result in different laboratory levels, radiological findings and disease progression. The goal of the present article is to determine whether the laboratory results and radiological findings were different in non-pregnant women (NPWs) of reproductive age and pregnant women (PWs) diagnosed with the Covid-19 infection. Methods Out of 34 patients, 15 (44.11%) PWs and 19 (55.8%) NPWs were included in the study. Age, comorbidities, complaints, vitals, respiratory rates, computed tomography (CT) findings and stages, as well as laboratory parameters, were recorded from the hospital database. Results Themean age of the PWs was of 27.6 ± 0.99 years, and that of the NPWs was of 37.63 ± 2.00; when agewas compared between the groups, a statistically significant difference (p=0.001) was found. The mean systolic blood pressure of the PWs was of 116.53 ± 11.35, and that of the NPWs was of 125.53 ± 13.00, and their difference was statistically significant (p=0.05). The difference in the minimum respiratory rates of the patients was also statistically significant (p=0.05). The platelet levels observed among the PWs with Covid-19 were lower than those of the NPWs (185.40 ± 39.09 x 109/mcL and 232.00 ± 71.04 x 109/mcL respectively; p=0.05). The mean D-dimer value of the PWs was lower in comparison to that of the NPWs (p<0.05). Conclusion The laboratory findings and imaging studiesmay differ between pregnant and non-pregnant populations. It is important to properly interpret these studies. Future studies with a higher number of patients are required to confirm these preliminary data.

Evaluación de la efectividad de las vacunas contra la COVID-19: orientación provisional / Evaluation of COVID-19 vaccine effectiveness

En este documento se presenta orientación provisional sobre las mejores prácticas para evaluar la efectividad de las vacunas contra la COVID-19 usando el diseño de estudio observacional. Se examinan las consideraciones esenciales del diseño, el análisis y la interpretación de las evaluaciones de la efectividad de las vacunas contra la COVID-19, dado que se pueden obtener resultados sesgados aun en entornos en los que la exhaustividad y la calidad de los datos son altas. Esta orientación se dirige principalmente a las evaluaciones realizadas en los países de ingresos bajos o medianos, pero la mayoría de los conceptos también son aplicables en entornos de ingresos altos.

Since its emergence in December 2019, SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), has taken a tremendous toll globally; by 28 February 2021, there have been over 110 million cases and 2.5 million deaths worldwide from COVID-19 (1). Although most COVID-19 deaths occur among older adults and persons with chronic comorbid medical conditions, deaths have occurred in persons of all ages. Moreover, the pandemic has caused widespread morbidity and necessitated control measures that have devastated economies worldwide. In response to the pandemic, the global efforts to develop multiple vaccines to protect against COVID-19 disease have been unrivalled in the history of public health. By the end of 2020, three COVID-19 vaccines have received Emergency Use Approval/Listing (EUA/EUL) by maturity level 4 regulatory authorities, based on reaching predefined criteria for safety and efficacy, and at least several dozen more are in clinical trials.

An Insight of the First Community Infected COVID-19 Patient in Beijing by Imported Case: Role of Deep Learning-Assisted CT Diagnosis / 中国医学科学杂志(英文版)

In the era of coronavirus disease 2019 (COVID-19) pandemic, imported COVID-19 cases pose great challenges to many countries. Chest CT examination is considered to be complementary to nucleic acid test for COVID-19 detection and diagnosis. We report the first community infected COVID-19 patient by an imported case in Beijing, which manifested as nodular lesions on chest CT imaging at the early stage. Deep Learning (DL)-based diagnostic systems quantitatively monitored the progress of pulmonary lesions in 6 days and timely made alert for suspected pneumonia, so that prompt medical isolation was taken. The patient was confirmed as COVID-19 case after nucleic acid test, for which the community transmission was prevented timely. The roles of DL-assisted diagnosis in helping radiologists screening suspected COVID cases were discussed.