Respiratory syncytial virus (RSV), historically being the major causative agent. RSV causes respiratory disease in young children worldwide and by the age of two years most children have been infected.
The aim of this study was to investigate the effect of passive smoking alone and in conjunction with breastfeeding and Crowding index and Family history of atopy in determining the risk of bronchitis in Children under of 5 years of age .
We studied 100 consecutive Children aged from (1)day to (60)months (56boys and 44 girls),median age 30 months, who required hospital admission for acute bronchiolitis at the Pediatric Department ,Children Welfare teaching hospital ,medical city complex - Baghdad.
The cases were compared with 100 patients at the same age groups with no history of Bronchilolitis .The following parameters was studied in both groups: Exposure to passive smoking, type of feeding (Breast, Bottle, and Mixed), Family history of atopy, and crowding index.
High level of exposure to passive smoking on the other hand significantly increase the risk of having bronchiolitis by (2.3) times compared to those with negative exposure. Breast feeding significantly decrease the risk of having bronchiolitis by 5 times compared to those on mixed and bottle feeding.
A positive family history of atopy significantly increase the risk of bronchiolitis by (9.5 )times . Subjects with moderately high crowding index (interquartile range )has 6.3 times of having increase the risk of bronchiolitis compared to those of living in uncroweded residence (first quartile crowding index).Highly crowding index (forth quartile)significantly increase the risk by 101 times compared to the those in un crowded (first quartile )residence.
Although Smoking , Lack of Breast feeding and family history of atopy are important risk factors for RSV bronchiolitis But Crowding seems to be the most important risks factors for RSV bronchiolitis in this study.