ABSTRACT
Outbreaks of acute gastroenteritis are a public health problem. Norovirus is known as the most common cause (50%). In Chile, immediate notification allows surveillance of these events. We describe an acute gastroenteritis outbreak that occurred in Antofagasta region, between March and April 2010. An observational study was conducted to perform the outbreak investigation. Local residents who met case definition were included. Stool samples, epidemiological surveys and environmental samples were requested. The outbreak began approximately on March 8, 2010 and lasted until April 28 with 31,036 reported cases (rate 54 per 1000 inhabitants). The most affected age group was between 25 and 44 years, and diarrhea was the main symptom (97% of cases). We determined the presence of norovirus genogroup II in clinical and environmental samples. This outbreak was caused by consumption of raw vegetables from La Chimba, which were watered and contaminated with treated sewage containing low concentration of free residual chlorine. Subsequently, the outbreak spread from person to person in a poor sanitary environment.
Antecedentes: Los brotes por gastroenteritis aguda constituyen un problema de salud pública. Se conoce al norovirus como la causa más común (50%). En Chile, la vigilancia de estos eventos, se establece mediante la notificación inmediata. Objetivo: Investigar y caracterizar el brote de gastroenteritis aguda ocurrido en la Región de Antofagasta, durante los meses de marzo y abril de 2010. Método: Se efectuó un estudio observacional descriptivo para realizar la investigación de brote. Se incluyó a residentes de la región que cumplían con la definición de caso. Se solicitó muestras de deposición, encuesta epidemiológica y muestras ambientales. Resultados: Se estimó que el brote comenzó el 8 de marzo de 2010 y duró hasta el 28 de abril del mismo año; se notificaron 31. 036 casos (tasa 54 por 1.000 habitantes). El grupo de 25 y 44 años de edad fue el más afectado y la diarrea fue el síntoma predominante (97% de los casos). Se determinó la presencia de norovirus genogrupo II en muestras clínicas y ambientales. Conclusiones: El brote se originó por el consumo crudo de hortalizas que provenían del sector La Chimba, las que fueron regadas y contaminadas con agua servida tratada que contenía baja concentración de cloro libre residual y posteriormente se propagó por transmisión persona-persona, en un ambiente sanitario deficiente.
Subject(s)
Adolescent , Adult , Child, Preschool , Female , Humans , Infant , Male , Middle Aged , Caliciviridae Infections/epidemiology , Disease Outbreaks , Gastroenteritis/epidemiology , Norovirus/isolation & purification , Acute Disease , Caliciviridae Infections/transmission , Chile/epidemiology , Feces/virology , Gastroenteritis/virologyABSTRACT
A sentinel-based outpatient and inpatient surveillance for rotavirus infection has been implemented in Chile. Aim: Update the impact of rotavirus infections in Chile. Methods: Ambulatory surveillance is performed in 14 centers from 8 Regions and hospital-based surveillance in 8 hospitals from three Regions (V, VIII and Metropolitan). Results: In 2007, 339 stool samples that represented 9.3 percent of all outpatient cases were studied of which 15 percent were rotavirus positive. A total of 2.074 children younger than 5 years of age were hospitalized representing 9 percent of all hospitalizations for this age group. Rotavirus was detected in 13.6 percent of these cases. Conclusions: In the current epidemiological situation, rotavirus surveillance needs to be sustained with increased efforts to detect cases in order to avoid underreporting. Serotype/genotype surveillance of rotavirus strains needs to be included in the near future.
En Chile, se realiza la vigilancia de gastroenteritis causadas por rotavirus en niños bajo 5 años a través de centros centinelas ambulatorios y hospitalarios. Objetivo: Conocer la epidemiología de las diarreas por rotavirus y evaluar la carga de morbi-mortalidad. Método: La vigilancia ambulatoria se desarrolla en 14 centros de 8 regiones y la vigilancia hospitalaria se lleva a cabo en 8 hospitales pediátricos de las regiones Vª, VIIIªy RM. Resultados: En 2007, 9,3 por ciento de las consultas por diarrea fue estudiada (339), detectándose rotavirus en 15 por ciento de ellas. Se hospitalizaron por diarrea, 2.074 casos, 9 por ciento del total de las hospitalizaciones en este grupo etario. De estas, 13,6 por ciento fueron por rotavirus. Conclusiones: Dada la situación epidemiológica actual, es importante mantener la vigilancia, ampliar la pesquisa de los casos, aplicar el protocolo de vigilancia establecido y determinar el serotipo/genotipo circulante en el país.
Subject(s)
Child, Preschool , Female , Humans , Infant , Male , Gastroenteritis/epidemiology , Gastroenteritis/virology , Rotavirus Infections/epidemiology , Sentinel Surveillance , Acute Disease , Chile/epidemiology , Diarrhea/epidemiology , Diarrhea/microbiology , IncidenceABSTRACT
Los hantavirus son virus envueltos, de genoma ARN trisegmentado. Los hantavirus americanos provienen de la subfamilia de roedores Sigmodontinae y pueden causar el síndrome cardiopulmonar por hantavirus (SCPH) mientras que los hantavirus europeos y asiáticos provienen de las subfamilias Murinae y Arvicolinae que pueden producir la fiebre hemorrágica con síndrome renal. En este artículo se describen las técnicas de laboratorio desarrolladas al momento actual para certificar la infección por hantavirus en humanos
Subject(s)
Humans , Animals , Orthohantavirus/isolation & purification , Hantavirus Pulmonary Syndrome/diagnosis , Vero Cells/virology , Clinical Laboratory Techniques , Orthohantavirus/pathogenicity , Immunoglobulin M , RNA , Rodentia/virologyABSTRACT
En Chile la infección humana por hantavirus está ligada al ratón Oligoryzomys longicaudatus, reportándose la circulación de hantavirus en especímenes capturados desde la Región Metropolitana hasta la XI Región. Se han notificado casos de síndrome cardiopulmonar por hantavirus desde la sexta a la undécima regiones. La emergencia de esta enfermedad en la población chilena estimuló el desarrollo de un laboratorio nacional de referencia para su diagnóstico etiológico. Se describen las etapas de desarrollo de este laboratorio y su contribución a establecer el trazado epidemiológico de la infección en Chile. Relatamos brevemente el aislamiento postmortem de virus Andes a partir de un niño
Subject(s)
Humans , Orthohantavirus/isolation & purification , Rodentia/virology , Hantavirus Pulmonary Syndrome/diagnosis , Contact Tracing , Orthohantavirus/pathogenicity , Immunohistochemistry , Reverse Transcriptase Polymerase Chain Reaction , Hantavirus Pulmonary Syndrome/etiologyABSTRACT
Background: Tropical spastic paraparesis (TSP) is an endemic disease in Chile. In most countries, only 50 percent of patients are seropositive to HTLV-I. However, new studies suggest that seronegative TSP is also associated with HTLV-I. Aim: To describe clinical and virological features of seronegative patients with TSP. Patients and methods: seventy two chilean patients with TSP, studied by clinical, radiological and laboratory methods during 1998, are reported. The determination of antibodies to HTLV-I was accomplished by ELISA, immunofluorescence and western-blot analysis. Polymerase chain reaction for tax and 5'Ltr genes was made using primers SK 43-44, LTR1 and LTR6. Results: Thirty one patients were HTLV-I positive and 41 were negative. No clinical, radiological or laboratory differences were observed between both groups. In seropositive patients, tax and 5'ltr viral gene sequences of the HTLV-I provirus were detected in DNA of peripheral blood mononuclear cells. In seronegative cases, sequences of tax gene were detected, exclusively, in 18 of 41 patients. Conclusions: These results confirm an association with HTLV-I infection in 43,9 percent of the TSP seronegative patients. These findings support the hypothesis that a defective provirus infects peripheral blood mononuclear cells in seronegative cases of TSP. The importance tax gene in the diagnosis of the TSP is also emphasized
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Genes, pX/genetics , Paraparesis, Tropical Spastic/virology , Enzyme-Linked Immunosorbent Assay , HTLV-I Infections , Case-Control Studies , Polymerase Chain Reaction , HTLV-I Antigens , Paraparesis, Tropical Spastic/complications , Paraparesis, Tropical Spastic/immunology , Sjogren's Syndrome/etiologyABSTRACT
We report eight patients with familial tropical spastic paraparesis belonging to four families. The diagnosis was reached by clinical, radiological and electrophysiological studies. Human lymphotropic virus type I infection was confirmed by ELISA, immunofluorescence essays, Western blot and polymerase chain reaction in DNA of peripheral blood mononuclear cells, using primers for tax and 5'ltr genes. In all these families there was a vertical transmission of the disease from the first to the second generation. All patients improved their spastic gait after prednisone treatment. Among patients of the second generation, all had dacrysialoadenitis, three had leukemia like lymphocytes in the blood smear, two had mycosis fungoides and one had hepatic cirrhosis