Browsing by Author "Martínez Valdebenito, Constanza Pamela"

Now showing 1 - 7 of 7
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    Aporte de la biología molecular en el diagnóstico de infecciones respiratorias agudas
    (2016) Budnik Ojeda, Isolda Cecilia; Ferres Garrido, Marcela Viviana; Pardo Tarrago, Trinidad; Edwards Tagle, Javiera; Labarca Trucios, Gonzalo Patricio; Reyes Zaldivar, Felipe Tomas; Martínez Valdebenito, Constanza Pamela; Montecinos Perret, Luisa Paola; Perret Pérez, Cecilia
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    Detección del SARS-CoV-2 mediante RT-qPCR utilizando saliva en pacientes ambulatorios con estudio de COVID-19
    (2022) Perret Pérez, Cecilia; Abarca Villaseca, Katia; Solari Gajardo, Sandra; Aguilera, Pablo; García-Huidobro Munita, Diego Nicolas; Olivares, Felipe; Palma, Carlos; Contreras, Ana María; Martínez Valdebenito, Constanza Pamela; Ferrés, Marcela
    La pandemia de COVID-19 ha afectado a millones de personas en todo el mundo. La identificación de sujetos infectados ha sido importante para el control. Objetivo: Evaluar el rendimiento deuna reacción de polimerasa en cadena (RPC) cuantitativa en tiempo real (en inglés: RT-qPCR) para SARS-CoV-2, utilizando saliva como matriz en comparación con un hisopado nasofaríngeo (HNF). Metodología: Se reclutaron adultos en atención ambulatoria, la mayoría sintomáticos. Fueron estudiadas 530 muestras pareadas de saliva e HNF con RT-qPCR. Resultados: Fueron positivas 59 muestras de HNF y 54 de saliva. La sensibilidad con saliva fue 91%, especificidad 100%, el valor predictor positivo (VPP) 100%, valor predictor negativo (VPN) 98%. El índice Kappa fue de 0,95 y LR-0,08. En promedio, el umbral de ciclo (en inglés cycle threshold-CT) de la saliva fue 3,99 puntos más alto que los de HNF (p < 0,0001) mostrando que la carga viral (CV) es menor en saliva. La carga viral en ambas disminuyó con el tiempo después del inicio de los síntomas. El muestreo de saliva fue preferido por los sujetos en lugar de HNF. Conclusión: Este estudio demuestra que la RPC para SARS-CoV-2 utilizando saliva, es adecuada para el diagnóstico de COVID-19 en adultos ambulatorios,especialmente en la etapa temprana de los síntomas.
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    Early versus deferred anti-SARS-CoV-2 convalescent plasma in patients admitted for COVID-19: A randomized phase II clinical trial
    (2021) Balcells Marty, Maria Elvira; Rojas Orellana, Luis Esteban; Martínez Valdebenito, Constanza Pamela; Ceballos Valdivielso, María Elena Andrea; Ferrés Garrido, Marcela Viviana; Chang Rathkamp, Mayling Raquel; Vizcaya Altamirano, María Cecilia; Mondaca Contreras, Sebastián Patricio; Huete Garín, Isidro Álvaro; Castro López, Ricardo Adolfo; Sarmiento Maldonado, Mauricio; Villarroel Del Pino, Luis Antonio; Pizarro Ibáñez, Alejandra Valentina; Ross Pérez, Patricio Daniel; Santander Toro, Jaime Andrés; Lara Hernández, Bárbara Alejandra; Ferrada Koch, Marcela Patricia; Vargas Salas, Sergio Sebastián; Beltrán Pávez, Carolina; Soto Rifo, Ricardo; Valiente Echeverria, Fernando Andrés; Caglevic, Christian; Mahave, Mauricio; Selman Bravo, Carolina Antoniett; Gazitúa, Raimundo; Briones, José Luis; Villarroel Espíndola, Franz; Balmaceda Araque, Carlos Felipe; Espinoza Sepúlveda, Manuel Antonio; Pereira Garces, Jaime; Nervi Nattero, Bruno; Le Corre Perez, Monique Nicole
    Background: Convalescent plasma (CP), despite limited evidence on its efficacy, is being widely used as a compassionate therapy for hospitalized patients with COVID-19. We aimed to evaluate the efficacy and safety of early CP therapy in COVID-19 progression.", "Methods and findings", "The study was an open-label, single-center randomized clinical trial performed in an academic medical center in Santiago, Chile, from May 10, 2020, to July 18, 2020, with final follow-up until August 17, 2020. The trial included patients hospitalized within the first 7 days of COVID-19 symptom onset, presenting risk factors for illness progression and not on mechanical ventilation. The intervention consisted of immediate CP (early plasma group) versus no CP unless developing prespecified criteria of deterioration (deferred plasma group). Additional standard treatment was allowed in both arms. The primary outcome was a composite of mechanical ventilation, hospitalization for >14 days, or death. The key secondary outcomes included time to respiratory failure, days of mechanical ventilation, hospital length of stay, mortality at 30 days, and SARS-CoV-2 real-time PCR clearance rate. Of 58 randomized patients (mean age, 65.8 years; 50% male), 57 (98.3%) completed the trial. A total of 13 (43.3%) participants from the deferred group received plasma based on clinical aggravation. We failed to find benefit in the primary outcome (32.1% versus 33.3%, odds ratio [OR] 0.95, 95% CI 0.32-2.84, p > 0.999) in the early versus deferred CP group. The in-hospital mortality rate was 17.9% versus 6.7% (OR 3.04, 95% CI 0.54-17.17 p = 0.246), mechanical ventilation 17.9% versus 6.7% (OR 3.04, 95% CI 0.54-17.17, p = 0.246), and prolonged hospitalization 21.4% versus 30.0% (OR 0.64, 95% CI, 0.19-2.10, p = 0.554) in the early versus deferred CP group, respectively. The viral clearance rate on day 3 (26% versus 8%, p = 0.204) and day 7 (38% versus 19%, p = 0.374) did not differ between groups. Two patients experienced serious adverse events within 6 hours after plasma transfusion. The main limitation of this study is the lack of statistical power to detect a smaller but clinically relevant therapeutic effect of CP, as well as not having confirmed neutralizing antibodies in donor before plasma infusion.", "Conclusions", "In the present study, we failed to find evidence of benefit in mortality, length of hospitalization, or mechanical ventilation requirement by immediate addition of CP therapy in the early stages of COVID-19 compared to its use only in case of patient deterioration.
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    Identificación de Rickettsia andeanae en dos regiones de Chile
    (2013) Abarca Villaseca, Katia; López, Javier; Acosta Jamett, Gerardo; Martínez Valdebenito, Constanza Pamela
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    Imported scrub typhus: first case in South America and review of the literature
    (2018) Weitzel, Thomas; Martínez Valdebenito, Constanza Pamela; Abarca Villaseca, Katia; Aylwin, Mabel; Jiang, Ju; Munita, Jose M.; Thompson, Luis; Richards, Allen L.
    Abstract Background Scrub typhus is a neglected vector-borne zoonosis causing life-threatening illnesses, endemic in the Asian-Pacific region and, as recently discovered, in southern Chile. Scrub typhus is rarely reported in travelers, most probably due to the lack of clinical experience and diagnostic tests in non-endemic countries. We report the first case of imported scrub typhus in South America. Case presentation A 62-year-old tourist from South Korea presented severely ill with fever, rash, and eschar in Santiago, Chile. Laboratory exams showed thrombocytopenia and elevated inflammation parameters, hepatic enzymes, and LDH. With the clinical suspicion of scrub typhus, empirical treatment with doxycycline was initiated and the patient recovered rapidly and without complications. The diagnosis was confirmed by IgM serology and by real-time PCR, which demonstrated infection with Orientia tsutsugamushi (Kawasaki clade). Conclusions Only due to the emerging clinical experience with endemic South American scrub typhus and the recent implementation of appropriate diagnostic techniques in Chile, were we able to firstly identify and adequately manage a severe case of imported scrub typhus in South America. Physicians attending febrile travelers need to be aware of this rickettsiosis, since it requires prompt treatment with doxycycline to avoid complications.Abstract Background Scrub typhus is a neglected vector-borne zoonosis causing life-threatening illnesses, endemic in the Asian-Pacific region and, as recently discovered, in southern Chile. Scrub typhus is rarely reported in travelers, most probably due to the lack of clinical experience and diagnostic tests in non-endemic countries. We report the first case of imported scrub typhus in South America. Case presentation A 62-year-old tourist from South Korea presented severely ill with fever, rash, and eschar in Santiago, Chile. Laboratory exams showed thrombocytopenia and elevated inflammation parameters, hepatic enzymes, and LDH. With the clinical suspicion of scrub typhus, empirical treatment with doxycycline was initiated and the patient recovered rapidly and without complications. The diagnosis was confirmed by IgM serology and by real-time PCR, which demonstrated infection with Orientia tsutsugamushi (Kawasaki clade). Conclusions Only due to the emerging clinical experience with endemic South American scrub typhus and the recent implementation of appropriate diagnostic techniques in Chile, were we able to firstly identify and adequately manage a severe case of imported scrub typhus in South America. Physicians attending febrile travelers need to be aware of this rickettsiosis, since it requires prompt treatment with doxycycline to avoid complications.
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    Reduced Immune Response to Inactivated Severe Acute Respiratory Syndrome Coronavirus 2 Vaccine in a Cohort of Immunocompromised Patients in Chile
    (Oxford University Press for the Infectious Diseases Society of America, 2022) Balcells Marty, María Elvira; Le Corre Pérez, Monique Nicole; Durán Santa Cruz, Josefina Gracia; Ceballos Valdivielso, María Elena Andrea; Vizcaya Altamirano, María Cecilia; Mondaca Contreras, Sebastián Patricio; Dib Marambio, Martin Javier; Rabagliati Borie, Ricardo Miguel; Sarmiento Maldonado, Mauricio; Burgos Cañete, Paula Isabel; Espinoza Sepúlveda, Manuel Antonio; Ferres Garrido, Marcela Viviana; Martínez Valdebenito, Constanza Pamela; Ruiz-Tagle Seguel, Cinthya Grace; Ortiz Koh, Catalina Alejandra; Ross Pérez, Patricio Daniel; Budnik Bitran, Sigall; Solari Gajardo, Sandra; Vizcaya Vergara, María De Los Ángeles; Lembach, Hanns; Berríos Rojas, Roslye; Melo González, Felipe; Rios Raggio, Mariana; Kalergis Parra, Alexis Mikes; Bueno Ramírez, Susan Marcela; Nervi Nattero, Bruno
    Background Inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines have been widely implemented in low- and middle-income countries. However, immunogenicity in immunocompromised patients has not been established. Herein, we aimed to evaluate immune response to CoronaVac vaccine in these patients. Methods This prospective cohort study included 193 participants with 5 different immunocompromising conditions and 67 controls, receiving 2 doses of CoronaVac 8-12 weeks before enrollment. The study was conducted between May and August 2021, at Red de Salud UC-CHRISTUS, Santiago, Chile. Neutralizing antibody (NAb) positivity, total anti-SARS-CoV-2 immunoglobulin G antibody (TAb) concentrations, and T-cell responses were determined. Results NAb positivity and median neutralizing activity were 83.1% and 51.2% for the control group versus 20.6% and 5.7% (both P < .001) in the solid organ transplant group, 41.5% and 19.2% (both P < .0001) in the autoimmune rheumatic diseases group, 43.3% (P < .001) and 21.4% (PP = .001) in the cancer with solid tumors group, 45.5% and 28.7% (both P < .001) in the human immunodeficiency virus (HIV) infection group, 64.3% and 56.6% (both differences not significant) in the hematopoietic stem cell transplant group, respectively. TAb seropositivity was also lower for the solid organ transplant (20.6%; P < .0001), rheumatic diseases (61%; P < .001), and HIV groups (70.9%; P = .003), compared with the control group (92.3%). On the other hand, the number of interferon gamma spot-forming T cells specific for SARS-CoV-2 tended to be lower in all immunocompromising conditions but did not differ significantly between groups. Conclusions Diverse immunocompromising conditions markedly reduce the humoral response to CoronaVac vaccine. These findings suggest that a boosting vaccination strategy should be considered in these vulnerable patients.
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    Respuesta inmune humoral inducida por la vacuna influenza en niños con diagnóstico de leucemia linfoblástica aguda
    (Sociedad Chilena de Infectología, 2020) Cerda Valenzuela, Carolina Angélica; Martínez Valdebenito, Constanza Pamela; Barriga Cifuentes, Francisco José; Contreras, Marcela; Vidal, Marcela; Moreno, Rosa; Claverie, Ximena; Contreras, Paola; Huenuman, Lesly; García Salum, Tamara Cristal; Rathnasighe, Raveen; Medina Silva, Rafael Andrés; Ferrés Garrido, Marcela Viviana; Le Corre Pérez, Monique Nicole
    Background: Patients with acute lymphoblastic leukemia (ALL) have high risk of severe influenza infection and vaccination is highly recommended. The immunogenicity and effectiveness of vaccination are lower than in healthy people. Aim: To evaluate the immune response induced by influenza vaccine in children with ALL and observe effectiveness. Method: Children with ALL in maintenance phase and healthy children were recruited. Blood samples were taken at vaccination day (D0) and at day 28 (D28). Humeral response was evaluated by hemaglutination inhibition test (HAI) against H1N1. Patients were followed up for one year, clinical data and influenza episodes were recorded. Results: 34 children with ALL and 9 healthy children were included. Concerning HAI on D28, 12/34 patients and 5/8 healthy children had titers >= 1/40, with seroprotection rates of 35 and 63% respectively. Seroprotected children were older than non-seroprotected ones. During follow-up, only 3 patients non seroprotected, presented influenza infection, without oxygen supplementation or critical care support. Discussion: Children with ALL had a lower seroprotection rate than healthy children. Nevertheless, none of the seroprotected children presented influenza infection, reinforcing the annual vaccination recommendation.