ABSTRACT
BACKGROUND: Recent information on the prevalence of allergic sensitization (AS) in children from low-income urban areas is limited. METHODS: We conducted a cross-sectional, randomized, population-based study to determine the prevalence of AS, and its relationship with asthma and rhinitis in low-income schoolchildren in Santiago, Chile. The parents answered a standardized questionnaire on respiratory symptoms, and a skin prick test (SPT) for common aeroallergens was performed on all children. RESULTS: In the 545 schoolchildren studied (mean age 8.3 ± 0.9 years), the prevalence of positive SPT was 25.5%. The current prevalence of asthma, rhinitis, and rhinoconjunctivitis was 20%, 43.4%, and 27.8%, respectively. SPT was positive in 30.6%, 32.8%, and 38.0% of children with current asthma, rhinitis, and rhinoconjunctivitis, respectively. Positive SPT was significantly associated with rhinitis and rhinoconjunctivitis (p < 0.001) but not with asthma. Breastfeeding for at least 4 months was significantly protective against AS (odds ratio [OR] 0.48, 95% confidence interval [CI] 0.26-0.78; p = 0.008); no other factor studied was associated with AS. CONCLUSIONS: The prevalence of AS was low; less than 40% of children with current asthma, rhinitis, or rhinoconjunctivitis symptoms evidenced AS. The prevalence of non-atopic asthma and rhinitis is consistent with previous findings in children from low-income urban areas. Other environmental factors, such as the high burden of respiratory infections and environmental pollution, might be more critical than atopy for developing asthma and rhinitis in schoolchildren from deprived urban areas.
INTRODUCCIÓN: La información reciente sobre la prevalencia de sensibilización alérgica (SA) en niños de áreas urbanas de bajos recursos es limitada. MÉTODOS: Se realizó un estudio transversal, aleatorio, a nivel poblacional, para determinar la prevalencia de SA y su relación con asma y rinitis en escolares de bajos recursos en Santiago de Chile. Los padres respondieron un cuestionario estandarizado de síntomas respiratorios y se realizaron pruebas cutáneas (PC) para alérgenos comunes en los niños. RESULTADOS: En los 545 escolares estudiados (media de edad 8.3 ± 0.9 años) la prevalencia de PC positivas fue del 25.5%. La prevalencia actual de asma, rinitis y rinoconjuntivitis fue del 20%, 43.4% y 27.8%, respectivamente. Las PC fueron positivas en el 30.6%, 32.8% y 38.0% de los niños con síntomas actuales de asma, rinitis y rinoconjuntivitis, respectivamente. La rinitis y la rinoconjuntivitis se asociaron significativamente con PC positiva (p < 0.001), pero no el asma. La lactancia materna por al menos cuatro meses protegió significativamente contra SA (razón de momios [RM] 0.48, intervalo de confianza [IC] 95% 0.26-0.78; p = 0.008); ningún otro factor estudiado se asoció con SA. CONCLUSIONES: La prevalencia de SA fue baja; menos del 40% de los niños con síntomas actuales de asma, rinitis o rinoconjuntivitis evidenció SA. La alta prevalencia de asma y rinitis no atópicas concuerda con hallazgos previos en niños de áreas urbanas de bajos ingresos. Otros factores ambientales como la alta carga de infecciones respiratorias y contaminación ambiental podrían ser más importantes que la atopia para el desarrollo de asma y rinitis en escolares de áreas urbanas desfavorecidas.
Subject(s)
Parents , Poverty , Child , Humans , Cross-Sectional StudiesABSTRACT
Abstract Background: Recent information on the prevalence of allergic sensitization (AS) in children from low-income urban areas is limited. Methods: We conducted a cross-sectional, randomized, population-based study to determine the prevalence of AS, and its relationship with asthma and rhinitis in low-income schoolchildren in Santiago, Chile. The parents answered a standardized questionnaire on respiratory symptoms, and a skin prick test (SPT) for common aeroallergens was performed on all children. Results: In the 545 schoolchildren studied (mean age 8.3 ± 0.9 years), the prevalence of positive SPT was 25.5%. The current prevalence of asthma, rhinitis, and rhinoconjunctivitis was 20%, 43.4%, and 27.8%, respectively. SPT was positive in 30.6%, 32.8%, and 38.0% of children with current asthma, rhinitis, and rhinoconjunctivitis, respectively. Positive SPT was significantly associated with rhinitis and rhinoconjunctivitis (p < 0.001) but not with asthma. Breastfeeding for at least 4 months was significantly protective against AS (odds ratio [OR] 0.48, 95% confidence interval [CI] 0.26-0.78; p = 0.008); no other factor studied was associated with AS. Conclusions: The prevalence of AS was low; less than 40% of children with current asthma, rhinitis, or rhinoconjunctivitis symptoms evidenced AS. The prevalence of non-atopic asthma and rhinitis is consistent with previous findings in children from low-income urban areas. Other environmental factors, such as the high burden of respiratory infections and environmental pollution, might be more critical than atopy for developing asthma and rhinitis in schoolchildren from deprived urban areas.
Resumen Introducción: La información reciente sobre la prevalencia de sensibilización alérgica (SA) en niños de áreas urbanas de bajos recursos es limitada. Métodos: Se realizó un estudio transversal, aleatorio, a nivel poblacional, para determinar la prevalencia de SA y su relación con asma y rinitis en escolares de bajos recursos en Santiago de Chile. Los padres respondieron un cuestionario estandarizado de síntomas respiratorios y se realizaron pruebas cutáneas (PC) para alérgenos comunes en los niños. Resultados: En los 545 escolares estudiados (media de edad 8.3 ± 0.9 años) la prevalencia de PC positivas fue del 25.5%. La prevalencia actual de asma, rinitis y rinoconjuntivitis fue del 20%, 43.4% y 27.8%, respectivamente. Las PC fueron positivas en el 30.6%, 32.8% y 38.0% de los niños con síntomas actuales de asma, rinitis y rinoconjuntivitis, respectivamente. La rinitis y la rinoconjuntivitis se asociaron significativamente con PC positiva (p < 0.001), pero no el asma. La lactancia materna por al menos cuatro meses protegió significativamente contra SA (razón de momios [RM] 0.48, intervalo de confianza [IC] 95% 0.26-0.78; p = 0.008); ningún otro factor estudiado se asoció con SA. Conclusiones: La prevalencia de SA fue baja; menos del 40% de los niños con síntomas actuales de asma, rinitis o rinoconjuntivitis evidenció SA. La alta prevalencia de asma y rinitis no atópicas concuerda con hallazgos previos en niños de áreas urbanas de bajos ingresos. Otros factores ambientales como la alta carga de infecciones respiratorias y contaminación ambiental podrían ser más importantes que la atopia para el desarrollo de asma y rinitis en escolares de áreas urbanas desfavorecidas.
ABSTRACT
BACKGROUND: The prevalence of atopy in asthmatic children is widely variable around the world as demonstrated by large multicentric international studies. AIM: To determine the prevalence of atopy, defined as a positive reaction to one or more allergens in the skin prick test (SPT), in children with persistent asthma. MATERIAL AND METHODS: We studied 1,199 children (54% male), aged between 4 and 16 years with confirmed diagnosis of asthma and followed at a Department of Pediatric Respiratory Medicine, between 2006 and 2011. SPT was performed according to international recommendations using standardized aeroallergens, in the forearm. A positive reaction was defined as a wheal ≥ 3 mm to one or more allergens. RESULTS: The overall prevalence of atopy (positive SPT) was 49.4% (95% confidence interval (CI) 46.5-52.2) and there was a significant trend towards a higher prevalence with increasing age (p < 0.01). The main allergens with positive reactions were Dermatophagoides with 24.9% (95% CI 26.7-31.9), grass 24.0% (95% CI 21.6-26.5), weeds 19.0% (95% CI 16.9-21.4), cat 17.7% (95% CI 15.4-20.2), and Alternaria with 11.0% (95% CI 9.1-13.1). Sixty five percent of positive children reacted to one or more allergens. There were no adverse reactions. CONCLUSIONS: In the southern metropolitan area of Santiago de Chile, half of children with asthma are sensitized to common aeroallergens.
Subject(s)
Allergens/analysis , Asthma/epidemiology , Hypersensitivity/epidemiology , Adolescent , Animals , Asthma/etiology , Cats , Child , Child, Preschool , Chile/epidemiology , Dogs , Female , Humans , Hypersensitivity/etiology , Male , Prevalence , Skin Tests , Surveys and QuestionnairesABSTRACT
Background: The prevalence of atopy in asthmatic children is widely variable around the world as demonstrated by large multicentric international studies. Aim: To determine the prevalence of atopy, defined as a positive reaction to one or more allergens in the skin prick test (SPT), in children with persistent asthma. Material and Methods: We studied 1,199 children (54% male), aged between 4 and 16 years with confirmed diagnosis of asthma and followed at a Department of Pediatric Respiratory Medicine, between 2006 and 2011. SPT was performed according to international recommendations using standardized aeroallergens, in the forearm. A positive reaction was defined as a wheal ≥ 3 mm to one or more allergens. Results: The overall prevalence of atopy (positive SPT) was 49.4% (95% confidence interval (CI) 46.5-52.2) and there was a significant trend towards a higher prevalence with increasing age (p < 0.01). The main allergens with positive reactions were Dermatophagoides with 24.9% (95% CI 26.7-31.9), grass 24.0% (95% CI 21.6-26.5), weeds 19.0% (95% CI 16.9-21.4), cat 17.7% (95% CI 15.4-20.2), and Alternaria with 11.0% (95% CI 9.1-13.1). Sixty five percent of positive children reacted to one or more allergens. There were no adverse reactions. Conclusions: In the southern metropolitan area of Santiago de Chile, half of children with asthma are sensitized to common aeroallergens.
Subject(s)
Adolescent , Animals , Cats , Child , Child, Preschool , Dogs , Female , Humans , Male , Allergens/analysis , Asthma/epidemiology , Hypersensitivity/epidemiology , Asthma/etiology , Chile/epidemiology , Hypersensitivity/etiology , Prevalence , Surveys and Questionnaires , Skin TestsABSTRACT
BACKGROUND: Highly active antiretroviral therapy (HAART) in HIV/AIDS infection induces an important reduction of the viral load (VL) and an immune system reconstitution. CD4+ T lymphocyte count is the immunological measurement commonly used for the follow up of HIV/AIDS patients. AIM: To study prospectively the restoration of the innate immune system in patients with HIV/AIDS infection during their first year on HAART. PATIENTS AND METHODS: 25 naive HIV/AIDS patients, from San José Hospital and University of Chile Clinical Hospital, Santiago, Chile, were studied between years 2002-2003. Every 4 months after HAART initiation, CD3+, CD4+, CD8+ T lymphocytes and CD16/56+ natural killer (NK) cells were quantified by flow cytometry. NK cell cytotoxicity was measured using radioactive chrome liberation (Cr51). Tumor necrosis factor alpha (TNF-alpha) and interleukin-10 (IL-10) were measured in peripheral blood mononuclear cells and viral load was determined using Amplicor HIV-1 from Roche Diagnostics Systems. RESULTS: Thirteen of the 25 patients continued in the study. They were all males, average age 35 years old (23-50). At baseline average CD4+ count was 146 cells/microL (31-362) and average viral load was 82.000 copies/mL (4.000-290.000). A raise in CD3+, CD4+, CD8+, and CD16/56 cells was noted at months 9-12 of therapy. Viral load became undetectable in the same period. NK cell function was decreased at the beginning of the therapy (1-4 months), reaching its highest values at months 9-12. There was no significant change in IL-10. TNF-alpha increased in six patients during the study. CONCLUSIONS: In this group of patients, innate immunity was restored during HAART. These results should be confirmed in studies with a longer follow up period and also measuring cytokines such as MIP-1a, MIP-1ss and RANTES.
