Résumé
RESUMEN Algunos estudios han encontrado que la severidad de la COVID-19 se asocia con una alta carga viral determinada por los números de ciclos (Ct) de amplificación de ADN de SARS-CoV-2. El objetivo fue determinar la relación entre el umbral de ciclos de PCR de SARS-CoV-2 y la severidad de la infección por el virus SARS-COV-2 en pacientes internados y ambulatorios en un hospital de referencia entre marzo a junio del 2021. Estudio retrospectivo observacional analítico de corte trasverso de pacientes adultos con COVID-19, ambulatorios e internados en el Hospital Nacional. Se incluyeron los pacientes cuya infección fue confirmada por RT-PCR para SARS-CoV-2, se consideró un punto de corte para Ct60 años (36,6%), estuvieron hospitalizados (69,8%), internados en sala (57,1%), y admitidos en cuidados intensivos (12,8%), tiempo medio de enfermedad 8,48 ± 4,2 días. La mortalidad fue de 22,2%. Se encontró mayor riesgo de fallecer para los pacientes con Ct 60 años (OR: 3,69; IC95%: 2,39-5,68). Estos dos factores permanecieron asociados con el óbito en el análisis multivariado. Hubo mayor riesgo de hospitalizarse y fallecer en los pacientes con Ct<25. El valor Ct podría ser útil para la predicción del curso clínico y el pronóstico de los pacientes con COVID-19.
ABSTRACT Some studies have found that severity of COVID-19 is associated with a high viral load determined by the number of cycles (Ct) of SARS-CoV-2 DNA amplification. The objective was to determine the relationship between the Ct value and the severity of the SARS-COV-2 virus infection in inpatients and outpatients at a reference hospital in Paraguay between March and June 2021. Cross-sectional retrospective study of adult patients with COVID-19, ambulatory and hospitalized admitted to the National Hospital. Patients whose infection was confirmed by RT-PCR for SARS-CoV-2 were included, a cut off point of Ct 60 years (36.6%), hospitalized (69.8%), admitted to ward (57.1%), and admitted to intensive care (12.8%), mean time of illness 8.48 ± 4.2 days and mortality was 22.2%. A higher risk of death was found for patients with Ct 60 years (OR: 3.69; 95% CI: 2.39-5.68). These two factors remained associated with death in the multivariate analysis. There was a higher risk of hospitalization and death in patients with TC <25. Ct value could be useful for predicting clinical course and prognosis of COVID-19 patients.
Résumé
【Objective】 To analyze the difference of the internal control (IC) Ct value of two sets of blood nucleic acid detection(NAT) systems for individual donation and explore the feasibility of the IC Ct value used as stability evaluation index of NAT system. 【Methods】 A total of 4342 blood samples were randomly selected from our center from June to November 2020, and the IC Ct values of NAT system were classified into three categories: 1) classified by detection items: HBV, HCV and HIV; 2) classified by sample type: negative control (NC), positive control (PC), internal quality control (QC), blood donor sample (S); 3) classified by different instruments: system A and system B, and the differences of IC Ct value were analyzed and compared. 【Results】 A total of 14 196 IC Ct values of NAT were collected, showing a non-normal distribution. 1) classified by detection items: there were differences in the median of overall IC Ct values of HBV, HCV and HIV (H=859.6, P0.05), except for HBV QC (Z=1 635)and S (Z=1 848 560), HCV S (Z=1 957 844), HIV S (Z= 2 217 855) (P<0.01). No difference in IC values (P<0.01) was noted for any detection items (NC, PC, QC and S) in the same set of detection system. 【Conclusion】 Although IC values trended to be different due to types of sample, the NC, PC, and QC samples that come with the original reagents were identical in the two detection systems. The change of IC Ct value may be used as an evaluation index for the stability of the detection system.