RESUMEN
To help assess the causes and frequency of acute respiratory illnesses (ARI) during the first 18 months of life in Chile, a cohort of 437 children born in good health between May 1991 and April 1992 was followed at an urban health clinic in northern Santiago. Information was obtained from medical checkups performed at the clinic, from emergency health care services, from private physicians, and from interviews with each child's mother when the child was enrolled in the study and when it was 6, 12, and 18 months old. Followup was completed for 379 (87%) of the children. ARI accounted for 67% of all 3762 episodes of illness recorded for these children in the 18-month study period, 1384 (55%) of the ARI episodes affecting the upper respiratory tract and the remaining 1144 (45%) affecting the lower. The overall rate of ARI observed was 33 episodes per 100 child-months of observation. The incidences of upper, lower, and total ARI episodes decreased significantly in the third six months of life. A statistically significant association was found between upper ARI (> or = 2 episodes) and maternal smoking (> or = 5 cigarettes per day), but no significant associations were found with any of the other risk factors studied. However, lower ARI (> or 2 episodes) was significantly associated with maternal schooling (< 8 years), a family history of atopic allergy, and substandard housing conditions; and lower ARI (> or = 4 episodes) was significantly associated with these factors and also with the existence of one or more siblings, birth in a cold season, limited breast-feeding (< 4 months), and low socioeconomic status. Significant associations were found between obstructive bronchitis episodes and most of the risk factors studied (gender, siblings, season of birth, duration of breast-feeding, maternal schooling, smoking, use of polluting fuels in the home, and a family history of atopic allergy); similarly, significant associations were found between the occurrence of pneumonia and many risk factors (including siblings, season of birth, duration of breast-feeding, maternal schooling, smoking, and socioeconomic level). Overall, 42 of the study children were hospitalized during the study period for lower tract ARI, and two children died of pneumonia at home during their first 6 months of life. The rate of hospitalization fell significantly with increasing age.
Asunto(s)
Enfermedades Respiratorias/epidemiología , Enfermedad Aguda , Adolescente , Adulto , Factores de Edad , Lactancia Materna , Bronquitis/epidemiología , Chile/epidemiología , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Lactante , Recién Nacido , Masculino , Factores de Riesgo , Factores Sexuales , Factores Socioeconómicos , Factores de Tiempo , Contaminación por Humo de TabacoRESUMEN
AIM: To measure the impact of day care attendance on lower respiratory tract infections in children under two years old in two urban settings with different degrees of air pollution. SUBJECTS AND METHODS: A 26 week follow up, during fall and winter of 1991 and 1992, was performed to 98 children (48 attending day care and 50 controls) coming from Santiago, a city affected by severe air pollution and 95 children (46 attending day care and 49 controls) coming from San Felipe and Los Andes (villages with low air pollution). The incidence of lower respiratory infections was recorded by trained personnel and expressed as rates per 100 weeks of follow up. Day care settings in San Felipe and Los Andes were state funded whereas those from Santiago were private. All premises had wooden or plastic floors and smoking was forbidden. During the follow up years, no respiratory epidemics were recorded. RESULTS: The socioeconomic level of children from San Felipe and Los Angeles was better. Children from Santiago were more exposed to tobacco smoke. The highest incidence of lower respiratory infections was found in children attending day care in San Felipe and Los Andes (31.2 episodes/100 weeks of observation), closely followed by control and day care attending children from Santiago (28.7 respectively) and control children from San Felipe and Los Andes (18.2). CONCLUSIONS: Day care attendance in areas with low air pollution increases the risk of lower respiratory infections. Instead, in highly polluted areas, the infection rates do not increase.