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
The experience of a group of 9 doctors and 6 nurses, most of them younger than 30years of age, whom were part of the several volunteer groups directed towards the most damaged earthquake regions, is described. The team had to overcome a number of intense personal emotions related with the magnitude of the destruction, especially in the "adobe"-constructed houses and villages, in order to provide useful medical support. Moving out of the hospital setting, reaching out to the community in schools and emergency posts proved to be important in rural communities. An appropriate coordination of the volunteer groups, with the simultaneous action of municipal and state health authorities, together with well-guided leadership, was critical for an effective response in the larger city of Talcahuano /Hualpén. Within the second week of the aftermath, acute respiratory and intestinal infections were the most common medical complaints together with intense -in many cases severe- emotional distress associated mostly with fear to after shakes ("replicas"), tsunami, and social unrest. The severe earthquake that struck Chile has left many lessons for the future that will need to be analyzed seriously and with the conviction that effective and timely prevention of catastrophic aftermath consequences, although costly, must be a key element of the country's development plan. More importantly, the hundreds if not thousands of volunteers from a variety of health related professions that were moved by the scenes of suffering, and whom responded to individual or group initiatives, allow to foresee that the nation has the moral stamina required to overcome the tragedy and become a better society.
Subject(s)
Adult , Female , Humans , Male , Earthquakes , Emotions , Relief Work/organization & administration , Volunteers/psychology , Chile , Volunteers/organization & administrationABSTRACT
The human bocavirus (HBoV), virus of the Parvoviridae family, discovered by molecular methods in 2005,has been reported in respiratory samples, stool, urine and blood, both in children and adults. Prevalence ratesrange from 0.8% in fecal samples of individuals with acute diarrhea, up to 19% in respiratory samples and blood.HBoV has been detected in up to 43% of nasopharyngeal samples in asymptomatic children. In Chile, HBoV wasdetected in 24.2% of nasopharyngeal swabs in children under 5 years of age with respiratory symptoms of which74% had coinfection with other viruses. In asymptomatic children under 5 years of age, 37.5% of NP sampleswere positive for HBoV. We discuss the role of HBoV as a causal agent of respiratory and/or enteric disease inlight of the high rates of coinfection and asymptomatic infections.
Subject(s)
Adult , Child , Child, Preschool , Humans , Bocavirus/isolation & purification , Gastrointestinal Diseases/virology , Parvoviridae Infections/virology , Respiratory Tract Infections/virology , Chile , SeasonsABSTRACT
The article briefly reviews the epidemiology of human papillomavirus (HPV) infection and associated diseases in the world and in Chile and the scientific information of the licensed HPV vaccines: Gardasil® and Cervarix®. Considering the available information, the Consultive Committee of Immunizations of the Chilean Society of Infectious Diseases, summarizes its conclusions and makes recommendations for vaccination against HPV in Chile.
El artículo revisa brevemente la epidemiología de las infecciones por virus papiloma humano (VPH) y las enfermedades asociadas, tanto en el mundo como en Chile y la información científica de las vacunas contra VPH licenciadas: Gardasil® y Cervarix®. Considerando la información disponible, el Comité Consultivo de Inmunizaciones de la Sociedad Chilena de Infectología, resume sus conclusiones y hace sus recomendaciones para la vacunación contra VPH en Chile.
Subject(s)
Adolescent , Adult , Female , Humans , Middle Aged , Young Adult , Advisory Committees , Alphapapillomavirus/immunology , Papillomavirus Vaccines , Papillomavirus Infections/prevention & control , Chile/epidemiology , Papillomavirus Infections/epidemiology , Papillomavirus Vaccines/adverse effects , Papillomavirus Vaccines/immunology , Societies, Medical , Young AdultABSTRACT
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
Molecular, clinical and epidemiolagical studies have established beyond doubt that human papiloma viruses (HPV) cause cervical cancer. The virus is also associated with genital warts and other less common cancers in oropharynx, vulva, vagina and penis. Worldwide, VPH genotypes 16 and 18 are the most common high risk genotypes, detected in near 70 percent of women with cervical cáncer. The discovery of a cause-effect relationship between several carcinogenic microorganisms and cancer open avenues for new diagnostic, treatment and prevention strategies. In this issue of Revista Médica de Chile, two papers on HPV are presented. Guzman and colleagues demonstrate that HPV can be detected in 66 percent to 77 percent of healthy male adolescents by polymerase chain reaction and that positivity depends on the site of the penis that is sampled. These results support the role of male to female transmission of high risk HPVs in Chile and should lead to even more active educational campaigns. The second paper provides recommendations for HPV vaccine use in Chile, generated by the Immunization Advisory Committee of the Chilean Infectious Disease Society. To issue these recommendations, the Committee analyzes the epidemiological information available on HPV infection and cervical cancer in Chile, vaccine safety and effectiveness data, and describes cost-effectiveness studies. Taking into account that universal vaccination is controversial the Committee favors vaccine use in Chile and it's incorporation into a national program. However, there is an indication that the country requires the implementation of an integrated surveillance approach including cross matching of data obtained from HPV genotype surveillance, monitoring of vaccination coverage, and surveillance of cervical cáncer The final decision of universal vaccine use in Chile should be based on a through analysis of information.
Subject(s)
Adolescent , Female , Humans , Male , Alphapapillomavirus/genetics , Papillomavirus Infections/virology , Papillomavirus Vaccines , Uterine Cervical Neoplasms/virology , Alphapapillomavirus/immunology , Chile/epidemiology , Papillomavirus Infections/epidemiology , Papillomavirus Infections/prevention & control , Uterine Cervical Neoplasms/epidemiology , Uterine Cervical Neoplasms/prevention & controlABSTRACT
This article briefly reviews the epidemiology of human papillomavirus (HPV) infection and associated diseases globally and in Chile, and the scientific ínformatíon of the licensed HPV vaccines: Gardasil® and Cervarix®. Considering the available information, the Advisory Committee on Immunizations of the Chilean Society of Infectious Diseases recommends vaccination of teenage girls, ideally before initiating sexual actívíty, Le. approximately at the age of 12 to 13 years and vaccination of women of any age if they have not started sexual activity. If women are vaccinated after initiating sexual activity, they should be informed of the lower efficacy of immunization if HPV infection has occurred. Education on responsible sexuality and sexually transmitted diseases should be maintained as a priority. Vaccination should be highly considered for inclusion in the National Immunization Program.
Subject(s)
Adolescent , Adult , Child , Female , Humans , Male , Middle Aged , Young Adult , Advisory Committees , Immunization , Papillomaviridae , Papillomavirus Infections/prevention & control , Papillomavirus Vaccines , Chile/epidemiology , Papillomaviridae/classification , Papillomaviridae/genetics , Papillomaviridae/immunology , Papillomavirus Infections/epidemiology , Papillomavirus Infections/virology , Papillomavirus Vaccines/adverse effects , Papillomavirus Vaccines/immunology , Societies, Medical , Young AdultABSTRACT
El timerosal es un derivado del mercurio utilizado desde 1930 como preservante de vacunas. En las últimas décadas ha sido cuestionada su seguridad, especialmente por la posibilidad de toxicidad neurológica. La revisión de varios estudios realizados en niños que recibieron vacunas que contienen timerosal y la posición de organismos de expertos internacionales en relación al uso de este compuesto en vacunas, permite al Comité Consultivo de Inmunizaciones concluir que no existe evidencia de eventos adversos en lactantes o niños por exposición al timerosal contenido en vacunas rutinarias y, por lo tanto, no habría razón para modificar las actuales prácticas de inmunización en Chile.
Thimerosal is a mercury derivative included in vaccines since 1930 with the aim to prevent microbial contamination. During the last decades, the use of thimerosal has been questioned, specifically because of a potential association with neurotoxicity. After a thorough review of published studies on pediatric use of thimerosal-containing vaccines, and of position papers from international expert groups, the Consultive Committee of Immunizations of the Chilean Society of Infectious Diseases concludes that there is no solid evidence of adverse events associated with the use of thimerosal containing vaccines in infants and children. Therefore, a change in current vaccine practices refererred to thimerosal-containing vaccines is not justified in Chile.
Subject(s)
Child , Humans , Infant , Preservatives, Pharmaceutical , Thimerosal , Vaccines/chemistry , Autistic Disorder/chemically induced , Chile , Preservatives, Pharmaceutical/adverse effects , Reference Standards , Societies, Medical , Thimerosal/adverse effects , Vaccines/adverse effectsABSTRACT
Rotavirus es la primera causa de diarrea aguda grave en niños bajo 3 años de edad en el mundo. Esta infección es responsable de 25 millones de consultas, 2 millones de hospitalizaciones y 440.000 muertes por año en niños con menos de 5 años. El desarrollo de vacunas anti-rotavirus ha sido un camino largo y tortuoso marcado por la abrupta caída de Rotashield® en 1999 debido a su asociación con invaginación intestinal. Luego de seis años de intensa investigación, el mundo celebra la licencia de dos nuevas vacunas que, a pesar de ser diferentes en su formulación y forma de administración, han demostrado ser seguras y no asociadas a invaginación intestinal, en estudios de Fase III de gran magnitud, que enrolaron más de 60.000 niños. Estas dos vacunas, Rotarix® de Glaxo SmithKline Biologicals y Rotateq® de Merck Sharp & Dohme son altamente eficaces contra diarrea grave causada por rotavirus de los serotipos más prevalentes en el mundo. La incorporación de estas vacunas, más temprano que tarde, especialmente en los países más pobres del mundo, requerirá de un esfuerzo conjunto de los gobiernos, laboratorios productores, organismos internacionales y no gubernamentales y fundaciones de beneficencia.
Subject(s)
Humans , Child , Efficacy , Rotavirus Infections/immunology , Rotavirus Infections/prevention & control , Rotavirus Vaccines/immunology , Rotavirus Vaccines/therapeutic use , Diarrhea/virology , Gastrointestinal Diseases/virology , Rotavirus Infections/genetics , Intussusception/chemically induced , Rotavirus Vaccines/adverse effects , Rotavirus Vaccines/genetics , Viral Vaccines/adverse effectsABSTRACT
Background. Intussusception (IS) is a potentially severe disease that affects an undetermined number of Chilean infants. The withdrawal of a rotavirus vaccine in 1999 due to its association with IS, highlighted the need for updated information on IS worldwide including Chile, before introduction of new vaccines. Aim: To estimate the incidence and to describe the epidemiology and clinical presentation of IS in the Metropolitan Area of Chile. Material and methods. IS cases occurring between 1996 and 2001 in the seven public pediatric hospitals and in six private clinics (during 2000 and 2001) were identified. Incidence rates were calculated using updated population estimates. A systematic review of the medical charts of IS cases occurring in the public hospitals for 2000-2001 was performed. Results. IS incidence rates for the Public Sector ranged from 32 to 39 per 100.000 children < 2 years of age. These figures did not vary significantly among the different Health Care Services, nor after inclusion of the private clinics. IS was more common in males (66%) and infants younger than 12 months (83%), with 67% of cases occurring between 3 and 8 months of age. The most common presenting symptoms were abdominal pain (90%), vomiting (86%), and rectal bleeding (75%). Ileocolic IS predominated (83%) and surgical correction was the preferred treatment (81%). No death occurred in this series. Conclusions: IS incidence rates were intermediate compared to other series, stable over time, and similar between the public and private sector. Clinical characteristics were similar to those previously reported with a disproportionately high use of surgical correction over enema, currently considered the preferred treatment option. (Rev MÚd Chile 2004; 132: 565-72).
Subject(s)
Humans , Male , Female , Infant , Intussusception/diagnosis , Intussusception/epidemiology , Chile/epidemiology , Intestinal Diseases , Incidence , Intussusception/surgery , Intussusception/therapyABSTRACT
Background: Human calciviruses (HuCVs) cause diarrhea outbreaks associated with consumption of contaminated food and water. Seroepidemiological studies in developing countries, suggest that HuCVs can cause acute gastroenteritis in children. Aim: To study the presence of Norwalk (NV) and Mexico (MX) virus, two HuCVs, in stools of Chilean children from different settings. Subjects and methods: ELISA tests for NV and MX were performed in 677 stool samples for children aged 0 to 132 years old, with acute diarrhea occurring in day care centers or consulting in outpatient clinics or emergency rooms. We also studied eight samples from children involved in a diarrhea outbreak that occurred in a rural community in 1992. A subset of samples was tested with polymerase chain reactions using different primers. Results: Only one sample from a child with acute diarrhea occurring in a day care center was positive for HuCV by polymerase chain reaction. Three samples from the outbreak were positive by the latter method and by ELISA. The HuCV obtained from the day care center was genetically different from other known HuCV. Conclusions: Despite the high seroprevalence, NV and MX viruses were detected in a very low proportion of Chilean children stools
Subject(s)
Humans , Child, Preschool , Infant , Child , Adolescent , Norwalk virus/isolation & purification , Feces/virology , Chile/epidemiology , Polymerase Chain Reaction , Disease Outbreaks/statistics & numerical data , Caliciviridae Infections , Diarrhea, Infantile/etiology , Gastroenteritis/etiologyABSTRACT
La epidemiología de la hepatitis A está cambiando en Chile como consecuencia del desarrollo económico y cultural. Estudios recientes de seroprevalencia efectuados en Santiago permiten afirmar que actualmente coexisten en el país poblaciones que adquieren la infección tempranamente en la vida y otras que permanecen susceptibles hasta la adultez. Dos vacunas elaboradas con virus inactivado, con alta eficacia y seguridad están licenciadas en el país y se comercializan libremente. La inexistencia de registros nacionales acabados sobre la incidencia de la enfermedad por edad y regiones geográficas dificulta efectuar estudios de costo/beneficio para considerar la introducción de la vacuna anti hepatitis A al Programa Ampliado de Inmunizaciones (PAI). Una acabada vigilancia de la morbimortalidad por hepatitis A y estudios de seroprevalencia representativos de todo el país permitirán orientar la decisión de las autoridades de salud hacia la aplicación programática de esta vacuna en relación con otras prioridades en el área. Es necesario evaluar la seroconversión conferida por las vacunas inactivadas en el primer año de vida a hijos de madres seropositivas en la perspectiva de combinar esta vacuna con las utilizadas en el PAI. Por otra parte, el impacto de la inmunización artificial temprana de una población altamente expuesta a la infección con una vacuna cuyo efecto protector es de duración aún desconocida, es un aspecto a vigilar en caso de iniciarse este programa. Se hace énfasis en la indicación de inmunización selectiva de grupos de mayor riesgo de infectarse (politransfundidos), homosexuales masculinos, drogadictos intravenosos), desarrollar enfermedad severa (portadores de hepatopatías crónicas) o impacto epidemiológico (manipuladores de alimentos)
Subject(s)
Humans , Hepatitis A/prevention & control , Viral Hepatitis Vaccines/therapeutic use , Chile/epidemiology , Hepatitis A/epidemiology , Vaccination Coverage , Risk Groups , Vaccines, Inactivated/therapeutic use , Viral Hepatitis Vaccines/economicsABSTRACT
Las pruebas disponibles para detección de rotavirus (RV) presentan diferente eficiencia en el diagnóstico. Se evaluaron aquí cuatro métodos de diagnóstico de RV en deposiciones. Con este objeto se analizaron 51 muestras de niños con diarrea aguda (21 RV positivos) por los métodos de electroforesis de ARN viral (Rotagel, ISP-Chile), aglutinación de látex (Rotavirus Antigen Látex Test, Meridian), ELISA (Pathfinder, Kallestad), e inmunoensayo ligado a aglutinación (RV-Test Pack, Abbott). Todas las muestras fueron corroboradas con un ensayo de ELISA confirmatorio y su resultado fue considerado el estándar para comnparaciones. La sensibilidad y específicidad para ELISA fue 100 y 90 por ciento; RV-Test Pack: 95 y 97 por ciento; electroforesis de ARN 81 y 100 por ciento; aglutinación de látex 71 y 100 por ciento. El tiempo de procesamiento de la muestra tuvo un rango entre 15 min (RV-Test Pack) a 120 min (Rotagel). El precio de costo por muestra (en US$) fue: RV-Test Pack 10,2; ELISA-Pathfinder; látex 2,4; y Rotagel 0,5. RV-Test Pack aparece como la prueba de elección para el diagnóstico de RV por su rapidez y confiabilidad, sin embargo su precio podría impedir su uso en numerosos centros clínicos. La prueba de ELISA mostró eficiencia diagnóstica similar, su precio es más bajo, pero tiene mayores requerimientos técnicos y un tiempo de procesamiento más largo
Subject(s)
Humans , Male , Female , Infant , Feces/parasitology , Predictive Value of Tests , Rotavirus/isolation & purification , Clinical Laboratory Techniques , Cohort Studies , Diarrhea, Infantile/diagnosis , Efficiency , Electrophoresis , Enzyme-Linked Immunosorbent Assay , Reproducibility of Results , RNA , Sensitivity and Specificity , Latex Fixation Tests/methodsABSTRACT
Protective immunity against rotavirus infection is directed against antigenic epitopes on the outer capsid proteins VP7 and VP4. The aim of this study was to characterize the VP7 and VP4 antigenic types circulating in different hospital areas of Santiago, Chile, obtained from children consulting for acute no bloody diarrhea in 5 hospitals representative of the 5 major health areas in Santiago. In addition, 256 rotavirus positive samples, obtained from children with acute diarrhea consulting in the north health area of Santiago between 1985-1987 were studied. All samples were processed for rotavirus by an ELISA and all rotavirus positive samples were selected for VP4 typing by PCR (types P1-P4). A total of 782 rotavirus positive samples were obtained of wich 618 (79 percent) were typeable for one specific VP7 type. VP7 type G1 represented 63 percent of the rotavirus positive samples and predominated in all areas evaluated throughout the entire period of observation. VP7 type G2 represented 13 percent of rotavirus samples, following G1 in predominance. G2 types decreased progressively in all areas in both study periods. G4 types were detected mainly during 1985-1987, and G3 types have so far not been detected. Preliminary analysis of VP4 types suggests that P1 types are predominant and closely associated with VP7 G1 type. These results are relevant for the adoption of appropiate preventive strategies for rotavirus infection, specifically aimed to the development of effective vaccines
Subject(s)
Rotavirus/genetics , Diarrhea, Infantile/microbiology , In Vitro Techniques , Specimen Handling , Enzyme-Linked Immunosorbent Assay , Polymerase Chain Reaction , Prospective Studies , Retrospective Studies , Epitopes/isolation & purificationABSTRACT
El virus Norwalk ha sido reconocido como un agente frecuente de diarrea aguda en países desarrollados, especialmente como causal de brotes en adultos. La información disponible en países en desarrollo y en poblaciones pediátricas es reducida. Nuestro objetivo fue evaluar la seroprevalencia para virus Norwalk en habitantes de Santiago, e identificar posibles factores de riesgo. Se evaluaron 291 sueros obtenidos entre los años 1990-1991 de individuos menores de 21 años, estratificados por nivel socioeconómico y edad. Para cada individuo se completó un cuestionario relacionado con variables demográficas, ambientales, de hábitos recreativos y de consumo de alimentos. Los sueros fueron evaluados para anticuerpos anti-virus Norwalk mediante test de ELISA basado en partículas virales recombinantes sintéticas. La seroprevalencia global para virus Norwalk fue de 83 por ciento y el nivel de seroprevalencia fue inversamente proporcional al estrato socioeconómico evaluado (p < 0,001). La seroprevalencia aumentó con la edad (p < 0,001) observándose un aumento significativo de seroprevalencia entre los 3 (47 por ciento) y 4 años (82 por ciento) de edad (p = 0,04). La seroprevalencia fue mayor en: individuos del sexo femenino (p = 0,006) aquellos con antecedente de baño en fuentes de agua dulce (p = 0,048), aquellos que presentaban antecedentes de consumo de mariscos crudos (p = 0,0001), vegetales no cocidos (p < 0,0001), y en aquellos niños con madres con menor nivel de educación (p = 0,009). En Santiago la seroprevalencia para virus Norwalk es alta, la adquisicón de anticuerpos ocurre mayoritariamente antes de los 5 años de edad y está fuertemente asociada al nivel socioeconómico al que pertenece el individuo. El consumo de mariscos y vegetales crudos así como el contacto con fuentes de agua potencialmente contaminadas parecen ser factores significativos de riesgo para esta infección. Estos resultados deben orientar el diseño de nuevos estudios prospectivos destinados a identificar la presencia de virus en individuos pertenecientes a grupos de mayor riesgo