[Correlation between real-time PCR cycle threshold and clinical classification of COVID-19]. / Correlación entre el umbral de ciclo de la RPC en tiempo real y la clasificación clínica de la COVID-19.

BACKGROUND: The cycle threshold (Ct) of real-time reverse transcription PCR (RT-qPCR) indicates the relative concentration of an RNA sequence, this value has been related to clinical profile in viral infections. AIM: To determine the correlation between the Ct value and the clinical classification of COVID-19. METHOD: A correlational cross-sectional study was carried out, the Ct values were obtained by RT-qPCR directed to the N gene of SARS-CoV-2, grouping them by means of a central robust estimator and related to the clinical classification of COVID-19. RESULTS: Of the 718 cases included in the study; 77.7% (558) were mild; 21.3% (153) moderate and 1% (7) severe. The Ct value was grouped into levels: low Ct < 18.83; medium Ct> 18.83-30.10 and high Ct> 30.10. There was a weak inverse significant correlation (p = 0.002; Spearman's rho = -0.117) between the Ct value and the clinical classification. The characteristics: sex, age under 65 years, fever, chills, diarrhea, anosmia, and overweightobesity were associated with the Ct value. CONCLUSION: The lower the Ct value, a classification of greater severity of COVID-19 is expected, however, because the correlation is weak, its usefulness as a severity predictor is limited.

Correlación entre el umbral de ciclo de la RPC en tiempo real y la clasificación clínica de la COVID-19 / Correlation between real-time PCR cycle threshold and clinical classification of COVID-19

INTRODUCCIÓN: El umbral de ciclo (en inglés cycle threshold-Ct) de la reacción de polimerasa en cadena en tiempo real con transcripción reversa (RT-qPCR) indica la concentración relativa de una secuencia de ARN; este valor se ha relacionado con la expresión de cuadros clínicos en infecciones virales. OBJETIVO: Determinar la correlación entre el valor Ct y la clasificación clínica de la COVID-19. MÉTODO: Se realizó un estudio transeccional correlacional; los valores Ct se obtuvieron mediante RT-qPCR dirigida al gen N del SARS-CoV-2 agrupándolos mediante un estimador robusto central y relacionándose con la clasificación clínica de la COVID-19. RESULTADOS: De los 718 casos incluidos en el estudio; 77,7% (558) fueron leves; 21,3% (153) moderados y 1% (7) graves. El valor Ct se agrupó en niveles: Ct bajo 18,83 - 30,10 y Ct alto > 30,10. Existió correlación significativa inversa débil (p = 0,002; rho de Spearman = -0,117) entre el valor Ct y la clasificación clínica. Las características: sexo, edad menor a 65 años, fiebre, escalofrío, diarrea, anosmia y sobrepeso-obesidad estuvieron asociadas al valor de Ct. CONCLUSIÓN: A menor valor Ct se espera una clasificación de mayor gravedad de la COVID-19; no obstante, debido a que la correlación es débil, su utilidad como predictor de gravedad es limitada.

BACKGROUND: The cycle threshold (Ct) of real-time reverse transcription PCR (RT-qPCR) indicates the relative concentration of an RNA sequence, this value has been related to clinical profile in viral infections. AIM: To determine the correlation between the Ct value and the clinical classification of COVID-19. METHOD: A correlational cross-sectional study was carried out, the Ct values were obtained by RT-qPCR directed to the N gene of SARS-CoV-2, grouping them by means of a central robust estimator and related to the clinical classification of COVID-19. RESULTS: Of the 718 cases included in the study; 77.7% (558) were mild; 21.3% (153) moderate and 1% (7) severe. The Ct value was grouped into levels: low Ct 18.83-30.10 and high Ct> 30.10. There was a weak inverse significant correlation (p = 0.002; Spearman's rho = -0.117) between the Ct value and the clinical classification. The characteristics: sex, age under 65 years, fever, chills, diarrhea, anosmia, and overweightobesity were associated with the Ct value. CONCLUSION: The lower the Ct value, a classification of greater severity of COVID-19 is expected, however, because the correlation is weak, its usefulness as a severity predictor is limited.

Geohelmintos y parámetros fisicoquímicos del suelo como indicadores de calidad ambiental en el distrito de José Crespo y Castillo, Huánuco / Geohelminths and physicochemical parameters of the soil as indicators of environmental quality in José Crespo y Castillo, Huánuco district

En la investigación se determinaron la presencia de geohelmintos y se evaluó la calidad ambiental del suelo mediante parámetros fisicoquímicos en el distrito de José Crespo y Castillo ­ Huánuco, Perú. Se detectaron y cuantificaron los geohelmintos, se caracterizó los perfiles modales y propiedades fisicoquímicas en función del Soil Taxonomy, y contraste con el estándar de calidad para el cadmio (Cd) y determinación del índice de calidad ambiental del suelo empleando el análisis de componentes principales. Los perfiles modales son Fluventic Eutrudepts, Lithic Udorthents, Typic Dystrudepts, Typic Dystrudepts - Lithic Udorthents, Typic Dystrudepts - Typic Endoaquents, Typic Endoaquents, Typic Eutrudepts - Typic Eutrudepts, Typic Udifluvents y Typic Udorthents; los parámetros fisicoquímicos textura, pH, materia orgánica, nitrógeno, fosforo disponible, potasio disponible, cadmio disponible, capacidad de intercambio catiónico efectivo, calcio, magnesio, aluminio, hidrogeno, bases y ácidos cambiables y porcentaje de saturación de aluminio, determinando que el cadmio disponible se encuentra dentro de los estándares de calidad ambiental del Perú; y el índice de calidad ambiental del suelo es de 41,48%, teniendo la calificación de un suelo regular de calidad ambiental. Y la contaminación por Ascaris lumbricoides fue en 25 de las calicatas (55,56%), presente en los 8 tipos de suelos catalogados, seguida de las unicinarias representadas por Necator americano y Ancylostoma duodenale en 14 calicatas (31,11%) de pH ligeramente a medianamente acido, y Taenias y Capilaria, ambos en el 8,29%; los geohelmintos como riesgo de salud pública, permanecen por largo de tiempo en el suelo, independientemente de la calidad y en amplios rangos de pH, favorecidos por niveles de sustratos orgánicos derivados de la antropogénesis(AU)

In the investigation, the presence of geohelminths was determined and the environmental quality of the soil was evaluated through physicochemical parameters in the district of José Crespo y Castillo - Huánuco, Peru. Geohelminths were detected and quantified and the modal profiles and physicochemical properties were characterized based on the Soil Taxonomy, and contrast with the quality standard for cadmium (Cd) and determination of the environmental quality index of the soil using the main component analysis. Modal profiles are Fluventic Eutrudepts, Lithic Udorthents, Typic Dystrudepts, Typic Dystrudepts - Lithic Udorthents, Typic Dystrudepts - Typic Endoaquents, Typic Endoaquents, Typic Eutrudepts - Typic Eutrudepts, Typic Udifluvents, and Typic Udorthents; the physicochemical parameters texture, pH, organic matter, nitrogen, available phosphorus, available potassium, available cadmium, effective cation exchange capacity, calcium, magnesium, aluminium, hydrogen, exchangeable bases and acids and percentage of aluminum saturation, determining that cadmium available is within the environmental quality standards of Peru; and the environmental quality index of the soil is 41.48%, having the qualification of a regular soil of environmental quality. And the contamination by Ascaris lumbricoides was in 25 of the pits (55.56%), present in the 8 types of cataloged soils, followed by the unicinarias represented by Necator americano and Ancylostoma duodenale in 14 pits (31.11%) of pH slightly to medium acid, and Taenias and Capilaria, both at 8.29%; As a public health risk, geohelminths remain in the soil for a long time, regardless of quality and in wide pH ranges, favored by levels of organic substrates derived from anthropogenesis(AU)