Risk Factors for Respiratory Syncytial Virus-associated Lower Respiratory Illnesses in the First Year of Life

The relation of breast feeding and other factors to the incidence of respiratory syncytial virus-associated lower respiratory tract illnes (RSV-LR) in the first year of life is examined. The study population is 1,179 healthy infants enrolled at birth between May 1980 and January 1984 into the Tucson Children's Respiratory Study, Tucson, Arizona. Each subject's data were assessed at each month of age during the first year of life, during those months when respiratory syncytial virus was isolated. A number of significant relations were observed, particularly between 1 and 3 months of age. At this age, the risk of having a RSV-LRI increased in association with <1-month or no breast feeding, with being male, and with increasing numbers of others sharing the child's bedroom