Abstract: Introduction: The prevalence of asthma in Chile ranges from 10.2 to 14.9%. In previous studies, the Araucanía Region has not been included. Objective: To determine the prevalence of asthma in the school po pulation of the Araucanía Region. Subjects and Method: The ISAAC questionnaires were used for asthma symptoms in addition to a questionnaire for recording sociodemographic data, belonging to the Mapuche ethnicity, type of heating, exposure to indoor air pollution, and family history. The Binomial Regression Model was used to evaluate the effect of each of the different variables of inter est, adjusting by age groups (6-7 and 13-14 years). The model also evaluated the additive interaction between these variables and age. Results: 823 surveys were applied, where the prevalence of asthma was 14.2% and 23.2% in the 6-7 year old group and the 13-14 year old group, respectively. 43.7% de clare to be Mapuche, 32.9% live in rural areas, and 81.4% use firewood as a heating method. Through binomial regression model analysis, where for the study group, living in the coastal commune was significantly associated with a lower prevalence of asthma (-13.2% [CI: -17.7 to -8.6]. The history of an asthmatic mother was significantly associated with a higher prevalence of asthma (17.9% [CI: 2.7 to 33.1]. Living in a rural area, to be Mapuche or the type of heating used, showed differences statistically significant (p 0.18, p 0.609 and p 0.480, respectively) Conclusion: 13-14 year-olds school children in the Araucanía Region presented a higher prevalence of asthma. There was an association with asthma in the mother where this increase is not associated with living in a rural area, to be Ma puche or type of heating.

Resumen: Introducción: La prevalencia de asma en Chile es de un 10,2 a un 14,9%. En estudios previos no se ha incluido la Región de la Araucanía. Objetivo: Determinar la prevalencia de asma en la población escolar de la Región de La Araucanía. Sujetos y Método: Se utilizó cuestionario ISAAC para síntomas de asma además de un cuestionario para registro de datos sociodemográficos, pertenencia a etnia mapuche, tipo de calefacción, exposición a contaminantes intradomiciliarios y antecedentes familiares. Se uti lizó el Modelo de Regresión Binomial para evaluar el efecto de cada una de las diferentes variables de interés, ajustando por grupos de edad (6-7 y 13-14 años). También el modelo evaluó la interacción aditiva entre dichas variables y la edad. Resultados: Se aplicaron 823 encuestas, siendo la prevalencia de asma de un 14,2% en el grupo de 6-7 años y de un 23,2% en el grupo de 13-14 años. El 43,7% se declara perteneciente a etnia mapuche, 32,9% vive en zonas rurales y 81,4% utiliza leña como mé todo de calefacción. Se realizó análisis con modelo de regresión binomial donde para el grupo total estudiado, el vivir en comuna costera se asoció de forma significativa a menor prevalencia de asma (-13,2 pp [IC: -17,7 a -8,6]. El antecedente de madre asmática se asoció significativamente a mayor prevalencia de asma (17,9pp [IC: 2,7 a 33,1]. El vivir en zona rural, la pertenencia a etnia mapuche ni el tipo de calefacción utilizado mostraron diferencias estadísticamente significativa (p 0,18, p 0,609 y p 0,480 respectivamente). Conclusión: En escolares de 13-14 años de la Araucanía, existe una mayor prevalencia de asma. Se observa una asociación con asma en la madre (y este aumento no está asocia do a vivir en zona rural, pertenencia a etnia mapuche ni tipo de calefacción.

Background: Early viral detection in acute respiratory infections (ARI) is essential to establish appropriate therapy and prevent nosocomial transmission. Objective: To compare the efficacy of indirect immunofluorescence technique (IIF) with the polymerase chain reaction (PCR) to identify respiratory viruses in children hospitalized for ARI. Methods: 47 nasopharyngeal aspirates of children ≤ 2 years with ARI were included. IFI included respiratory syncytial virus (RSV), adenovirus, influenza A and B and parainfluenza. PCR also included the detection of metapneumovirus, enterovirus/rhinovirus, bocavirus and coronavirus. Sensitivity, specificity, positive and negative predictive value (VPP/NPV) and kappa correlation for RSV were estimated by IIF compared to PCR. Results: The IIF detected only RSV (29; 61.7%). PCR detected several viruses, including RSV in 26 cases (55.3%), followed by bocavirus (29.8%), rhinovirus/enterovirus (21.3%), adenovirus (14.9%) and parainfluenza (4,3%) among others, with 35.5% of coinfection. The IIF presented sensitivity: 85.7%, specificity: 73.6%, PPV: 82.7%, NPV: 77.7% and kappa: 0.5990 (95% CI, 0.3636-0.8346) for RSV. Conclusion: The IIF presents good sensitivity, but moderate specificity for RSV. However, IIF fails to detect other respiratory viruses. The introduction of PCR would improve the etiological diagnosis of ARI of viral origin.

Resumen Introducción: La temprana detección viral en infecciones respiratorias agudas (IRA) es esencial para establecer una terapia apropiada y prevenir el contagio intrahospitalario. Objetivo: Comparar la eficacia de la técnica de inmunofluorescencia indirecta (IFI) con la reacción de polimerasa en cadena (RPC) para identificar virus respiratorios en niños hospitalizados por IRA. Métodos: Se incluyeron 47 aspirados nasofaríngeos de niños ≤ 2 años con IRA. La IFI incluyó virus respiratorio sincicial (VRS), adenovirus, influenza A y B y parainfluenza. La RPC incluyó, además, la detección de metapneumovirus, enterovirus/rinovirus, bocavirus y coronavirus. Se estimó sensibilidad, especificidad, valor predictor positivo y negativo (VPP/VPN) y correlación kappa para VRS mediante IFI en comparación a la RPC. Resultados: La IFI detectó únicamente VRS (29; 61,7%). La RPC detectó diversos virus, entre ellos VRS en 26 casos (55,3%), seguido por bocavirus (29,8%), enterovirus/ rinovirus (21,3%), adenovirus (14,9%) y parainfluenza (4,3%) entre otros, con 35,5% de co-infección. La IFI presentó sensibilidad: 85,7%, especificidad: 73,6%, VPP: 82,7%, VPN: 77,7% y kappa: 0,5990 (IC 95%; 0,36360,8346) para VRS. Conclusión: La IFI presenta buena sensibilidad, pero moderada especificidad para VRS. Sin embargo, falla en la detección de otros virus respiratorios. La introducción de RPC permitiría mejorar el diagnóstico etiológico de las IRA de origen viral.

S. pneumoniae is a significant cause of community-acquired pneumonia in the elderly, and accounts for the majority of the pneumonia deaths among the elderly. We conducted this randomized double-blind study to evaluate the immune response to a 23-valent pneumococcal polysaccharide vaccine and the persistence of antibodies two years after the vaccination in an elderly population in Santiago, Chile. A total of 118 elderly nursing home residents received either the pneumococcal or a tetanus control vaccine. Serum samples were taken at enrolment, at two months, and at two years post-vaccination. Pre-vaccination anti-pneumococcal antibody geometric mean concentrations (GMC) were similar in both study groups, with increased levels of antibodies found only against serotype 14. The pneumococcal vaccine was highly immunogenic at 2 months, and titers remained high two years after the vaccination for the 10 serotypes studied in this elderly population. The results thus support the benefits of this pneumococcal vaccine in this elderly population who are at increased risk of invasive pneumococcal disease.

Background: S pneumoniae is the main cause of community-acquired pneumonia in the elderly, group that concentrates 95% of deaths. Aim: To assess the prevalence of nasal carriage of S pneumoniae in institutionalized elderly patients. Material and methods: One hundred eighteen institutionalized subjects aged over 60 years (65 males) were enrolled. Since they were also participating in a controlled protocol related to the immunogenicity of an anti-pneumococcal vaccine, our investigation was also blind and randomized. According to randomization, they received pneumococcal or tetanic vaccine. Nasal swab cultures were taken at the beginning of the trial and two months after vaccination. According to recommended methods, we identified S pneumoniae, the serotypes and their antimicrobial susceptibility. Results: In the first nasal sample, 16% of subjects were positive for S pneumoniae. The second sample was positive in 12%. Of the 33 isolated serotypes, 9.1% demonstrated intermediate resistance to penicillin and 3.3% were resistant to chloramphenicol. Conclusions: The study demonstrated a greater percentage of colonized patients than in the general population. The isolated serotypes are the same that cause invasive diseases in this age group, according to data of the Institute of Public Health of Chile. There were no differences in the percentage of colonization between subjects vaccinated against S pneumoniae and control groups, after two months of follow up. Isolated strains had a low resistance to penicillin. High level resistance was not observed

Background: Telithromycin is a new ketolide antimicrobial, that can be useful for the treatment of respiratory infections. Aim: To compare in vitro activity of telithromycin against respiratory pathogens, isolated in outpatient clinics. Material and methods: Two hundred eighty strains isolated from patients with respiratory infections, were studied. The strains studied were S pneumoniae, penicillin sensitive (SPNS:57); intermediate (SPNI:35), resistant (SPNR:25); S pyogenes (SP:57); H influenzae (HIN 51); M catarrhalis (MC:25) and S aureus meticillin sensitive (SAUS:30). Minimal inhibitory concentration (MIC) by broth microdilution was studied for telitrhomycin and levofloxacin in all strains. Other antimicrobials studied, but not in all strains were erythromycin, clindamycin, trimetoprim sulphamethoxazole, oxacillin, amoxicillin-clavulanic acid and cefuroxime. Results: All strains were sensible to telithromycin at a concentration 4 µg/ml. MIC 90 and its range for SPNS was 0.03 µg/ml (0.004-0.12), for SPNI was 0.03 µg/ml (0.004-025), for SPNR was 0.06 µg/ml (0.004-0.25), for HIN was 2 µg/ml (0.12-4), for SP was 0.5 µg/ml (0.004-2), for MC was 0.5 µg/ml (0.06-2) and for SAU was 0.25 µg/ml (0.06-0.25). Conclusions: All studied pathogens were sensible to telithromycin in vitro. This antimicrobial is an alternative for the treatment of community acquired respiratory infections