[Etiologic diagnosis in meningitis and encephalitis molecular biology techniques]. / Diagnóstico etiológico en meningitis y encefalitis por técnicas de biología molecular.

INTRODUCTION: The aetiological study of infections of the central nervous system has traditionally been performed using bacterial cultures and, more recently, using polymerase chain reaction (PCR) for herpes simplex virus (HSV). Bacterial cultures may not have good performance, especially in the context of patients who have received antibiotics prior to sampling, and a request for HSV only by PCR reduces the information to only one aetiological agent. The aim of this study is to determine the infectious causes of meningitis and encephalitis, using traditional microbiology and molecular biology to improve the aetiological diagnosis of these diseases. PATIENTS AND METHOD: A prospective study was conducted on 19 patients with suspected meningitis, admitted to the Luis Calvo Mackenna Hospital in Santiago, Chile, from March 1, 2011 to March 30, 2012. After obtaining informed consent, the CSF samples underwent cytochemical study, conventional culture, multiplex PCR for the major producing bacterial meningitis (N. meningitidis, S. pneumoniae, H. influenzae), real-time single PCR for HSV-1 and 2, VZV, EBV, CMV, HHV-6 and enterovirus. Clinical and epidemiological data were also collected from the clinical records. RESULTS: Of the 19 patients analysed, 2 were diagnosed by conventional methods and 7 by adding molecular biology (increase to 37%). Three patients had meningitis due to S. pneumoniae, one due to Enterobacter cloacae, 2 patients meningoencephalitis HSV-1, and one VZV meningitis. CONCLUSIONS: The addition of PCR to conventional diagnostic methods in CNS infections increases the probability of finding the causal agent. This allows a more adequate, timely and rational management of the disease.

[Thoraco-abdominal pseudotumor associated with Bartonella henselae and Eikenella corrodens in an immunocompetent patient]. / Pseudotumor toraco-abdominal asociado a Bartonella henselae y Eikenella corrodens en un paciente pediátrico inmunocompetente.

Inflammatory pseudotumors are a rare pathology and scarcely reported in the literature and have been associated with polymicrobial infections. Here, we present the case of a 9 years old boy from Bolivia, who presented with abdominal pain, weight loss and vomiting, who was diagnosed with a thoraco-abdominal pseudotumor. The micro-biology and molecular laboratories in tissue allowed the identification of one of the probable etiological agents.

[Panton-Valentine leukocidin toxin associated methicillin-susceptible Staphylococcus aureus infection: a report of two pediatric cases]. / Staphylococcus aureus sensible a meticilina, productor de leucocidina de Panton Valentine. A propósito de dos casos pediátricos de infección osteoarticular.

Staphylococcus aureus colonizes the nasopharynx in one third of healthy individuals and is also responsible for several infections in pediatrics such as endocarditis, pneumonia and osteoarticular infections. It has several virulence mechanisms, such as Panton Valentine leukocidin (PVL), which is an exotoxin that causes cell death. It is commonly related to methicillin-resistant Staphylococcus aureus (MRSA) and more serious pulmonary and musculoskeletal infections. However, PVL is not exclusive to MRSA. Two clinical cases of patients with infection by methicillin-sensitive Staphylococcus aureus producing this exotoxin are presented.

[Serratia marcescens multifocal osteomyelitis in a child with chronic granulomatous disease]. / Osteomielitis multifocal por Serratia marcescens en un niño con enfermedad granulomatosa crónica.

Chronic granulomatous disease (CGD) is a rare primary immuno-deficiency. It is characterized by an alteration in the function of phagocytes causing recurrent bacterial and fungal infections. This is a case report of a child with multifocal osteomyelitis by Serratia marcescens, an infrequent as a cause of bone infections, although associated with CGD. The study of infections with clinical presentation and unusual agents should lead to suspicion of CGD. The diagnosis early in life, as well as timely antimicrobial treatment and the subsequent antimicrobial prophylaxis will avoid infectious recurrences and sequelae.

[Clinical and cost characterization of hospitalization associated with varicella in children from the Metropolitan Region and Valparaíso, Chile]. / Caracterización clínica y de costos de la hospitalización asociada a varicela en niños de la Región Metropolitana y de Valparaíso, Chile.

BACKGROUND: Varicella is a relevant infection in Chile and may cause serious complications and death, which could be associated with significant health care resource utilization and associated costs. In Chile, sentinel surveillance is carried out only on an outpatient basis, without knowing the impact of varicella in serious cases who need to be hospitalized. AIM: To describe the clinical characteristics and the costs associated with hospitalized children with diagnosis of varicella prior to the vaccine introduction in the National Immunization Program in Chile. PATIENTS AND METHODS: A multicenter, observational, and retrospective study in hospitalized children (0-15 years) with a diagnosis of varicella, were conducted in five hospitals in Chile between January 2011 and December 2015. A review of the clinical records was performed to evaluate the clinical characteristics of the disease and costs associated with hospitalization episodes for varicella. RESULTS: A total of 685 hospitalized children for varicella were included in this study. The median age was 3 years (IQR: 1-5), most children were between 1 and 4 years of age (52% of total cases). 56% were male, and only 7 patients (1%) had a history of previous varicella vaccination. The median lenght of days of hospitalization was 3 days (IQR: 2-5). 13% of the cases required hospitalization in a more complex care unit, 6% in the intermediate unit and 7% in the pediatric intensive treatment unit, both with a median stay of 3 days. The main complications were: skin and soft tissue infections (42%), neurologic (8%) and septic or toxic shock (4%). There were 3 cases of death (0.4%). The direct cost of a varicella case was US $ 417, the indirect cost was US $ 224 and the proportional cost of a case of death was US $ 3,575. It is estimated that the total cost of a hospitalized varicella case in Chile was US $ 4,216. CONCLUSIONS: Varicella is associated with a significant burden of disease in Chile. The median hospital stay was three days with 13% of cases requiring medical care in a complex unit, with high associated costs which could be significantly reduced with the recently incorporation of the varicella vaccine into the National Immunization Program.

[Recommendations for the suspected diagnosis and management of Multisystemic Inflammatory Syndrome (MIS-C) in the context of a SARS-CoV-2 pandemic. April 2021]. / Recomendaciones para la sospecha diagnóstica y manejo del Síndrome Inflamatorio Multisistémico (SIM-COVID-19) en contexto pandemia SARS-CoV-2. Abril 2021.

Multisystem inflammatory syndrome temporally associated with COVID-19 (MIS-C) is a post-infectious complication described in children and adolescents with previous exposure to SARS-CoV-2. Because of its potential to evolve to severe disease -including cardiovascular impairment and multiple organ failure it requires a prompt diagnosis and appropriate management, including intensive care for most cases. These guidelines compile recent information from scientific literature, from our local clinical experiences during the past pandemic year, and have been discussed by experts. The recommendations provided are meant to help the clinical work of health teams attending the pediatric population.

[Recommendations for the diagnosis and management of cytomegalovirus infection in pregnant woman and newborn infant]. / Recomendaciones para el diagnóstico y manejo de la infección por citomegalovirus en la mujer embarazada y el recién nacido.

The Chilean Society of Infectology, through its Neonatal Infections Committee in conjunction with the Chilean Society of Obstetrics and Gynecology, propose a document for the Diagnosis and Management of Cytomegalovirus Infection in Pregnant Woman and Newborn Infant. This guideline suggests the management of mother and child infection, its diagnostic and therapeutic options. Considers the global and Latin American epidemiology, with recommendations for clinical and laboratory evaluation; diagnostic criteria, therapeutic approaches according to the clinical situation, analyzes prevention measures and establishes a national proposal for monitoring this disease.

[Central nervous system infection by Bartonella henselae associated with a choroid plexus papilloma]. / Infección por Bartonella henselae con compromiso de sistema nervioso central, asociado a un papiloma del plexo coroídeo.

Bartonella henselae infection is a prevalent illness in Chile. It presents generally as a cat scratch disease or as a prolonged fever syndrome. There are atypical manifestations, which include central nervous system, bone, cardiac and hepato-esplenic compromised. We present an adolescent case with a history of fever, vomiting and ataxia, whose diagnosis was a central nervous system infection by Bartonella henselae associated with a choroid plexus papilloma. This case corresponds to an unusual presentation, with a challenging diagnosis. It is controversial whether to treat this patient, which antimicrobial is the right choice and how long the treatment should be.

Staphylococcus aureus sensible a meticilina, productor de leucocidina de Panton Valentine: a propósito de dos casos pediátricos de infección osteoarticular / Panton-Valentine leukocidin toxin associated methicillin-susceptible Staphylococcus aureus infection: a report of two pediatric cases

Resumen Staphylococcus aureus coloniza la nasofaringe en un tercio de los individuos sanos y además es causante de infecciones graves en pediatría, como endocarditis, neumonía e infecciones osteoarticulares. Posee varios mecanismos de virulencia, siendo la leucocidina de Panton Valentine (LPV) uno de ellos, una exotoxina que causa muerte celular. Su producción está comúnmente relacionada con Staphylococcus aureus resistente a meticilina (SARM) e infecciones pulmonares y musculo-esqueléticas graves. Sin embargo, la producción de LPV no es exclusiva de SARM. Se presentan dos casos clínicos de pacientes con infección por Staphylococcus aureus sensible a meticilina productora de esta exotoxina.

Abstract Staphylococcus aureus colonizes the nasopharynx in one third of healthy individuals and is also responsible for several infections in pediatrics such as endocarditis, pneumonia and osteoarticular infections. It has several virulence mechanisms, such as Panton Valentine leukocidin (PVL), which is an exotoxin that causes cell death. It is commonly related to methicillin-resistant Staphylococcus aureus (MRSA) and more serious pulmonary and musculoskeletal infections. However, PVL is not exclusive to MRSA. Two clinical cases of patients with infection by methicillin-sensitive Staphylococcus aureus producing this exotoxin are presented.

Osteomielitis multifocal por Serratia marcescens en un niño con enfermedad granulomatosa crónica / Serratia marcescens multifocal osteomyelitis in a child with chronic granulomatous disease

Resumen La enfermedad granulomatosa crónica (EGC) es una inmunode-ficiencia primaria poco frecuente. Se caracteriza por una alteración en la función de los fagocitos, causando infecciones recurrentes bacterianas y fúngicas. Presentamos el caso clínico de un niño con una osteomielitis multifocal por Serratia marcescens , microorganismo infrecuente como causa de infecciones óseas en niños, aunque asociado a la EGC. El estudio de infecciones con presentación clínica y agentes inhabituales deben hacer sospechar una EGC. Su diagnóstico precoz en la vida, así como el tratamiento antimicrobiano oportuno y el uso posterior de una profilaxis antimicrobiana adecuada logrará evitar recurrencias infecciosas y secuelas.

Abstract Chronic granulomatous disease (CGD) is a rare primary immuno-deficiency. It is characterized by an alteration in the function of phagocytes causing recurrent bacterial and fungal infections. This is a case report of a child with multifocal osteomyelitis by Serratia marcescens, an infrequent as a cause of bone infections, although associated with CGD. The study of infections with clinical presentation and unusual agents should lead to suspicion of CGD. The diagnosis early in life, as well as timely antimicrobial treatment and the subsequent antimicrobial prophylaxis will avoid infectious recurrences and sequelae.

Pseudotumor toraco-abdominal asociado a Bartonella henselae y Eikenella corrodens en un paciente pediátrico inmunocompetente / Thoraco-abdominal pseudotumor associated with Bartonella henselae and Eikenella corrodens in an immunocompetent patient

Resumen Los pseudotumores inflamatorios son poco frecuentes y escasamente descritos en la literatura y han sido asociados a infecciones polimicrobianas. Se presenta el caso de un niño de 9 años, procedente de Bolivia, quien consultó por dolor abdominal, baja de peso y vómitos, diagnosticándose un pseudotumor tóraco-abdominal. El laboratorio clínico, mediante el estudio de biología molecular en tejido, permitió la identificación de uno de los probables agentes etiológicos.

Abstract Inflammatory pseudotumors are a rare pathology and scarcely reported in the literature and have been associated with polymicrobial infections. Here, we present the case of a 9 years old boy from Bolivia, who presented with abdominal pain, weight loss and vomiting, who was diagnosed with a thoraco-abdominal pseudotumor. The micro-biology and molecular laboratories in tissue allowed the identification of one of the probable etiological agents.

Caracterización clínica y de costos de la hospitalización asociada a varicela en niños de la Región Metropolitana y de Valparaíso, Chile / Clinical and cost characterization of hospitalization associated with varicella in children from the Metropolitan Region and Valparaíso, Chile

INTRODUCCIÓN: La varicela es una infección relevante en la salud pública de Chile, pudiendo causar en algunas ocasiones complicaciones graves e incluso la muerte, lo que se asocia a un significativo gasto en salud. En Chile sólo se realiza vigilancia centinela a nivel ambulatorio, sin conocerse el impacto de la varicela en casos más graves que determinan hospitalización. OBJETIVOS: Realizar una descripción clínica y de los costos asociados a la atención de niños hospitalizados con diagnóstico de varicela, en años previos a la introducción de la vacuna en el Programa Nacional de Inmunización en Chile. MATERIALES Y MÉTODOS: Estudio multicéntrico, observacional y retrospectivo, en todos los casos de niños hospitalizados (0-15 años) con diagnóstico de varicela, entre enero de 2011 y diciembre de 2015 en cinco hospitales de Chile. Se realizó revisión de fichas para evaluar características clínicas de la enfermedad y los costos asociados a la hospitalización por varicela. RESULTADOS: Un total de 685 hospitalizaciones por varicela fueron incluidas en el estudio. La mediana de edad fue de 3 años (RIC:1-5), siendo la mayoría de los niños con edades comprendidas entre los 1 y 4 años (52% del total de casos). El 56% fueron hombres y sólo 7 niño s (1%) tuvieron antecedente de vacuna varicela. La mediana de días de hospitalización fue de 3 días en cada episodio (RIC: 2-5). El 13% de los casos requirió hospitalización en unidades de mayor complejidad, 7% de los niños ingresó a Unidad de Tratamiento Intensivo y 6% ingresó a Intermedio, ambos con una mediana de 3 días de hospitalización. Las principales complicaciones fueron: infección de piel y tejidos blandos (42%), alteraciones neurológicas (8%) y shock séptico/tóxico (4%). La letalidad fue de 0,4%. El costo de un caso de varicela considerando los costos directos fue de US$417, el costo indirecto fue de US$224 y los costos proporcionales de una muerte de US$3.575. Se estima que el costo total de un caso de varicela hospitalizado en Chile, considerando todos los factores anteriores, fue de US$4.216. CONCLUSIONES: La varicela es una enfermedad inmunoprevenible frecuente. Se observaron casos con una mediana de 3 días de hospitalización por complicaciones, con 13% de los casos requiriendo hospitalización en unidades de mayor complejidad, con un alto costo asociado, que se estima podría disminuir significativamente con la reciente incorporación de la vacuna al Programa Nacional de Inmunizaciones.

BACKGROUND: Varicella is a relevant infection in Chile and may cause serious complications and death, which could be associated with significant health care resource utilization and associated costs. In Chile, sentinel surveillance is carried out only on an outpatient basis, without knowing the impact of varicella in serious cases who need to be hospitalized. AIM: To describe the clinical characteristics and the costs associated with hospitalized children with diagnosis of varicella prior to the vaccine introduction in the National Immunization Program in Chile. PATIENTS AND METHODS: A multicenter, observational, and retrospective study in hospitalized children (0-15 years) with a diagnosis of varicella, were conducted in five hospitals in Chile between January 2011 and December 2015. A review of the clinical records was performed to evaluate the clinical characteristics of the disease and costs associated with hospitalization episodes for varicella. RESULTS: A total of 685 hospitalized children for varicella were included in this study. The median age was 3 years (IQR: 1-5), most children were between 1 and 4 years of age (52% of total cases). 56% were male, and only 7 patients (1%) had a history of previous varicella vaccination. The median lenght of days of hospitalization was 3 days (IQR: 2-5). 13% of the cases required hospitalization in a more complex care unit, 6% in the intermediate unit and 7% in the pediatric intensive treatment unit, both with a median stay of 3 days. The main complications were: skin and soft tissue infections (42%), neurologic (8%) and septic or toxic shock (4%). There were 3 cases of death (0.4%). The direct cost of a varicella case was US $ 417, the indirect cost was US $ 224 and the proportional cost of a case of death was US $ 3,575. It is estimated that the total cost of a hospitalized varicella case in Chile was US $ 4,216. CONCLUSIONS: Varicella is associated with a significant burden of disease in Chile. The median hospital stay was three days with 13% of cases requiring medical care in a complex unit, with high associated costs which could be significantly reduced with the recently incorporation of the varicella vaccine into the National Immunization Program.

Recomendaciones para la sospecha diagnóstica y manejo del Síndrome Inflamatorio Multisistémico (SIM-COVID-19) en contexto pandemia SARS-CoV-2. Abril 2021 / Recommendations for the suspected diagnosis and management of Multisystemic Inflammatory Syndrome (MIS-C) in the context of a SARS-CoV-2 pandemic. April 2021

Resumen El síndrome inflamatorio multisistémico asociado a COVID-19 (SIM-COVID-19) es una complicación post-infecciosa descrita en niños y adolescentes con antecedente de exposición a SARS-CoV-2. Su potencial de evolución clínica grave, con compromiso hemodinámico y de falla de múltiples órganos lo convierten en una identidad que requiere de sospecha temprana, rápido diagnóstico y manejo adecuado, incluyendo terapia intensiva en la mayoría de los casos. Las siguientes recomendaciones recopilan información de la literatura científica, de la experiencia nacional en este año de pandemia y han sido consensuadas con expertos. Se presentan como guías de manejo de modo de facilitar el trabajo de equipos de salud a cargo de la atención pediátrica.

Abstract Multisystem inflammatory syndrome temporally associated with COVID-19 (MIS-C) is a post-infectious complication described in children and adolescents with previous exposure to SARS-CoV-2. Because of its potential to evolve to severe disease -including cardiovascular impairment and multiple organ failure it requires a prompt diagnosis and appropriate management, including intensive care for most cases. These guidelines compile recent information from scientific literature, from our local clinical experiences during the past pandemic year, and have been discussed by experts. The recommendations provided are meant to help the clinical work of health teams attending the pediatric population.

Recomendaciones para el diagnóstico y manejo de la infección por citomegalovirus en la mujer embarazada y el recién nacido / Recommendations for the diagnosis and management of cytomegalovirus infection in pregnant woman and newborn infant

Resumen La Sociedad Chilena de Infectología, a través de su Comité de Infecciones Neonatales, en conjunto con la Sociedad Chilena de Obstetricia y Ginecología, proponen un documento de diagnóstico y manejo de la Infección por Citomegalovirus en la Mujer Embarazada y el Recién Nacido. Esta guía aborda el manejo de la infección en el binomio, su enfrentamiento diagnóstico y terapéutico, orientado al equipo de salud que atiende a mujeres embarazadas y recién nacidos con infección por citomegalovirus (CMV) en Chile. Considera la situación epidemiológica global y latinoamericana, con recomendaciones para la evaluación clínica y de laboratorio; establece criterios de diagnóstico, propone enfoques terapéuticos de acuerdo a la situación clínica, analiza las medidas de prevención y establece una propuesta nacional para el seguimiento de esta enfermedad. Se ha puesto especial énfasis en entregar, de forma práctica, y con la mayor evidencia posible, las recomendaciones para el manejo del binomio con infección por CMV.

Abstract The Chilean Society of Infectology, through its Neonatal Infections Committee in conjunction with the Chilean Society of Obstetrics and Gynecology, propose a document for the Diagnosis and Management of Cytomegalovirus Infection in Pregnant Woman and Newborn Infant. This guideline suggests the management of mother and child infection, its diagnostic and therapeutic options. Considers the global and Latin American epidemiology, with recommendations for clinical and laboratory evaluation; diagnostic criteria, therapeutic approaches according to the clinical situation, analyzes prevention measures and establishes a national proposal for monitoring this disease.

Recomendaciones para el diagnóstico y el manejo de la infección por citomegalovirus en la mujer embarazada y el recién nacido / Recommendations for the diagnosis and management of cytomegalovirus infection in pregnant women and newborns

Resumen La Sociedad Chilena de Infectología, a través de su Comité de Infecciones Neonatales, en conjunto con la Sociedad Chilena de Obstetricia y Ginecología, proponen un documento de diagnóstico y manejo de la infección por citomegalovirus (CMV) en la mujer embarazada y el recién nacido. Esta guía aborda el manejo de la infección en el binomio, su enfrentamiento diagnóstico y terapéutico, orientado al equipo de salud que atiende a mujeres embarazadas y recién nacidos con infección por CMV en Chile. Considera la situación epidemiológica global y latinoamericana, con recomendaciones para la evaluación clínica y de laboratorio; establece criterios de diagnóstico, propone enfoques terapéuticos de acuerdo a la situación clínica, analiza las medidas de prevención y establece una propuesta nacional para el seguimiento de esta enfermedad. Se ha puesto especial énfasis en entregar, de forma práctica, y con la mayor evidencia posible, las recomendaciones para el manejo del binomio con infección por CMV.

Abstract The Chilean Society of Infectology, through its Neonatal Infections Committee in conjunction with the Chilean Society of Obstetrics and Gynecology, propose a document for the Diagnosis and Management of Cytomegalovirus Infection in Pregnancy and Newborn. This guideline suggests the management of mother and child infection, its diagnostic and therapeutic options. Considers the global and Latin American epidemiology, with recommendations for clinical and laboratory evaluation, diagnostic criteria, therapeutic approaches according to the clinical situation, analyzes prevention measures and establishes a national proposal for monitoring this disease.

Infección por Bartonella henselae con compromiso de sistema nervioso central, asociado a un papiloma del plexo coroídeo / Central nervous system infection by Bartonella henselae associated with a choroid plexus papilloma

Resumen La infección por Bartonella henselae es una enfermedad prevalente en nuestro país. En general, se presenta como la enfermedad por arañazo de gato o un síndrome febril prolongado. Existen manifestaciones atípicas dentro de las cuales está el compromiso óseo, cardíaco, hepatoesplénico y del sistema nervioso central. Se presenta el caso de una adolescente con historia de vómitos, fiebre y ataxia, en que se diagnosticó una infección por Bartonella henselae con compromiso del sistema nervioso central, asociada a un papiloma del plexo coroídeo. Este caso corresponde a una presentación inusual, de difícil diagnóstico. Su tratamiento es motivo de controversia, tanto en si es necesario tratar, la elección del antimicrobiano, como su duración.

Bartonella henselae infection is a prevalent illness in Chile. It presents generally as a cat scratch disease or as a prolonged fever syndrome. There are atypical manifestations, which include central nervous system, bone, cardiac and hepato-esplenic compromised. We present an adolescent case with a history of fever, vomiting and ataxia, whose diagnosis was a central nervous system infection by Bartonella henselae associated with a choroid plexus papilloma. This case corresponds to an unusual presentation, with a challenging diagnosis. It is controversial whether to treat this patient, which antimicrobial is the right choice and how long the treatment should be.

Diagnóstico etiológico en meningitis y encefalitis por técnicas de biología molecular / Etiologic diagnosis in meningitis and encephalitis molecular biology techniques

Introducción: El estudio etiológico de las infecciones del sistema nervioso central se ha realizado tradicionalmente con cultivos bacterianos y con reacción en cadena de la polimerasa (PCR) para virus herpes simple (VHS). Los cultivos bacterianos pueden disminuir su rendimiento en pacientes que hayan usado antibióticos previos a la toma de muestra, y el solicitar PCR solo para virus VHS reduce el diagnóstico etiológico a un solo agente. El objetivo de este trabajo fue determinar las causas infecciosas en meningitis y encefalitis en niños, utilizando conjuntamente la microbiología convencional y la biología molecular, con el fin de mejorar el diagnóstico etiológico de estas enfermedades. Pacientes y método: Se estudiaron 19 pacientes con sospecha de meningitis y encefalitis, de manera prospectiva, hospitalizados en el hospital Luis Calvo Mackenna en Santiago de Chile, entre el 1 de marzo de 2011 y el 30 de marzo de 2012. Luego de obtener el consentimiento informado, a las muestras de LCR se les realizó examen citoquímico, cultivo, PCR múltiple bacteriana (N. meningitidis, S. pneumoniae, H. influenzae) y PCR en tiempo real para HSV-1 y 2, VVZ, VEB, CMV, VHH-6 y enterovirus. Se recabaron datos clínicos y epidemiológicos desde la ficha clínica del paciente. Resultados: De los 19 pacientes analizados 2 (10%) fueron diagnosticados por métodos microbiológicos convencionales y 7 (37%) al adicionar biología molecular (p = 0,02). Tres pacientes presentaron meningitis por S. pneumoniae, uno por Enterobacter cloacae, 2 pacientes meningoencefalitis por VHS-1 y uno meningitis por VVZ. Conclusiones: La adición de la PCR a los métodos microbiológicos convencionales de diagnóstico en las infecciones del sistema nervioso central aumenta significativamente la probabilidad de detectar el agente causal. La incorporación rutinaria del diagnóstico molecular permitiría un manejo más oportuno y racional.

Introduction: The aetiological study of infections of the central nervous system has traditionally been performed using bacterial cultures and, more recently, using polymerase chain reaction (PCR) for herpes simplex virus (HSV). Bacterial cultures may not have good performance, especially in the context of patients who have received antibiotics prior to sampling, and a request for HSV only by PCR reduces the information to only one aetiological agent. The aim of this study is to determine the infectious causes of meningitis and encephalitis, using traditional microbiology and molecular biology to improve the aetiological diagnosis of these diseases. Patients and method: A prospective study was conducted on 19 patients with suspected meningitis, admitted to the Luis Calvo Mackenna Hospital in Santiago, Chile, from March 1, 2011 to March 30, 2012. After obtaining informed consent, the CSF samples underwent cytochemical study, conventional culture, multiplex PCR for the major producing bacterial meningitis (N. meningitidis, S. pneumoniae, H. influenzae), real-time single PCR for HSV-1 and 2, VZV, EBV, CMV, HHV-6 and enterovirus. Clinical and epidemiological data were also collected from the clinical records. Results: Of the 19 patients analysed, 2 were diagnosed by conventional methods and 7 by adding molecular biology (increase to 37%). Three patients had meningitis due to S. pneumoniae, one due to Enterobacter cloacae, 2 patients meningoencephalitis HSV-1, and one VZV meningitis. Conclusions: The addition of PCR to conventional diagnostic methods in CNS infections increases the probability of finding the causal agent. This allows a more adequate, timely and rational management of the disease.