ABSTRACT
OBJECTIVE: To evaluate the factors associated with false negatives in RT-qPCR in patients with mild-moderate symptoms of COVID-19. MATERIALS AND METHODS: This was a cross-sectional study that used a random sample of non-hospitalized patients from the primary care management division of the Healthcare Area of Leon (58 RT-qPCR-positive cases and 52 RT-qPCR-negative cases). Information regarding symptoms was collected and all patients were simultaneously tested using two rapid diagnostic tests - RDTs (Combined - cRDT and Differentiated - dRDT). The association between symptoms and SARS-CoV-2 infection was evaluated by non-conditional logistic regression, with estimation of Odds Ratio. RESULTS: A total of 110 subjects were studied, 52% of whom were women (mean age: 48.2±11.0 years). There were 42.3% of negative RT-qPCRs that were positive in some RDTs. Fever over 38°C (present in 35.5% of cases) and anosmia (present in 41.8%) were the symptoms most associated with SARS-CoV-2 infection, a relationship that remained statistically significant in patients with negative RT-qPCR and some positive RDT (aOR=6.64; 95%CI=1.33-33.13 and aOR=19.38; 95% CI=3.69-101.89, respectively). CONCLUSIONS: RT-qPCR is the technique of choice in the diagnosis of SARS-CoV-2 infection, but it is not exempt from false negatives. Our results show that patients who present mild or moderate symptoms with negative RT-qPCR, but with fever and/or anosmia, should be considered as suspicious cases and should be evaluated with other diagnostic methods
OBJETIVO: Evaluar los factores asociados con falsos negativos a RT-qPCR negativa y sintomatología leve o moderada de COVID-19. MATERIALES Y MÉTODOS: Estudio transversal. Se utilizó una muestra aleatoria de pacientes no hospitalizados de la Gerencia de Atención Primaria del Área de Salud de León (58 con RT-qPCR positiva y 52 con RT-qPCR negativa). Se recogió información sobre síntomas, y a todos se les realizaron simultáneamente dos pruebas de diagnóstico rápido (PDR): combinada (PRD-C) y diferenciada (PRD-D). La asociación de los síntomas con la infección por SARS-CoV-2 se evaluó mediante regresión logística no condicional, con el cálculo de odds ratio (OR). RESULTADOS: Se estudiaron un total de 110 personas, y el 52% de ellas fueron mujeres (edad media: 48,2±11,0años). El 42,3% de las RT-qPCR negativas dieron positivo en algún PDR. La fiebre de más de 38°C (presente en el 35,5% de los casos) y la anosmia (presente en el 41,2%) fueron los síntomas más asociados a la infección por SARS-CoV-2, relación que se mantuvo estadísticamente significativa en pacientes con RT-qPCR negativa y algún PDR positivo (ORa: 6,64; IC95%: 1,33-33,13, y ORa: 19,38; IC95%: 3,69-101,89, respectivamente). CONCLUSIONES: La RT-qPCR es la técnica de elección en el diagnóstico de la infección por SARS-CoV-2, pero no está exenta de falsos negativos. Nuestros resultados ponen de manifiesto que los pacientes que presentan síntomas leves o moderados con RT-qPCR negativa pero con fiebre y/o anosmia deben ser considerados casos sospechosos y deben ser valorados con otros métodos diagnósticos
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Coronavirus Infections/epidemiology , Real-Time Polymerase Chain Reaction/methods , Severe acute respiratory syndrome-related coronavirus/isolation & purification , Severe Acute Respiratory Syndrome/epidemiology , Cross-Sectional Studies , Real-Time Polymerase Chain Reaction/statistics & numerical data , Fever/etiology , Olfaction Disorders/epidemiologyABSTRACT
OBJECTIVE: To evaluate the factors associated with false negatives in RT-qPCR in patients with mild-moderate symptoms of COVID-19. MATERIALS AND METHODS: This was a cross-sectional study that used a random sample of non-hospitalized patients from the primary care management division of the Healthcare Area of Leon (58 RT-qPCR-positive cases and 52 RT-qPCR-negative cases). Information regarding symptoms was collected and all patients were simultaneously tested using two rapid diagnostic tests - RDTs (Combined - cRDT and Differentiated - dRDT). The association between symptoms and SARS-CoV-2 infection was evaluated by non-conditional logistic regression, with estimation of Odds Ratio. RESULTS: A total of 110 subjects were studied, 52% of whom were women (mean age: 48.2±11.0 years). There were 42.3% of negative RT-qPCRs that were positive in some RDTs. Fever over 38°C (present in 35.5% of cases) and anosmia (present in 41.8%) were the symptoms most associated with SARS-CoV-2 infection, a relationship that remained statistically significant in patients with negative RT-qPCR and some positive RDT (aOR=6.64; 95%CI=1.33-33.13 and aOR=19.38; 95% CI=3.69-101.89, respectively). CONCLUSIONS: RT-qPCR is the technique of choice in the diagnosis of SARS-CoV-2 infection, but it is not exempt from false negatives. Our results show that patients who present mild or moderate symptoms with negative RT-qPCR, but with fever and/or anosmia, should be considered as suspicious cases and should be evaluated with other diagnostic methods.
