摘要：Objectives. We sought to quantify the effect of good smoking hygiene on infant risk of respiratory tract infection in the first 12 months of life. Methods. A cohort of 4486 infants in Tasmania, Australia, was followed from birth to 12 months of age for hospitalization with respiratory infection. Case ascertainment was 98.2%. Results. Relative to the infants of mothers who smoked postpartum but never in the same room with their infants, risk of hospitalization was 56% (95% confidence interval [CI] = 13%, 119%) higher if the mother smoked in the same room with the infant, 73% (95% CI = 18%, 157%) higher if the mother smoked when holding the infant, and 95% (95% CI = 28%, 298%) higher if the mother smoked while feeding the infant. Conclusions. Parents who smoke should not smoke with their infants present in the same room. Postnatal exposure of infants to cigarette smoke is causally associated with an increased risk of lower respiratory tract infections such as bronchitis and pneumonia, increased prevalence of fluid in the middle ear, symptoms of upper respiratory tract irritation, and a small but significant reduction in lung function. 1 This exposure also has been linked with new cases of childhood asthma and with additional episodes and increased severity of symptoms in asthmatic children. 1, 2 Medical authorities therefore recommend that parents provide a smoke-free environment for infants and children. The Committee on Substance Abuse of the American Academy of Pediatrics advocates that caregivers ask parents about tobacco use and smoke exposure at each consultation from the first prenatal visit onward. Parents who smoke should be offered assistance to stop smoking. Those parents who cannot quit should be encouraged to smoke outside the home. 3 Earlier studies have suggested that the physical distance between the new baby and the smoking parent correlates with the amount of cotinine in the baby’s urine, 3, 4 that urinary cotinine concentrations are lower when parents refrain from smoking in the same room with the baby, 5– 7 and that lower urinary cotinine is associated with reduced risk of respiratory infection in some 8– 11 though not all 12 studies of infants. The protective contribution of not smoking in the vicinity of the infant has not been fully evaluated for respiratory tract infection, however. We undertook the first investigation of whether parents who smoke can nevertheless reduce the increased risk of respiratory infection for their infants by exercising good “smoking hygiene” (i.e., never smoking in the same room with the infant or while holding or feeding the infant). We report the results of a 12-month follow-up on a cohort of 4486 infants conducted with extensive standardized information on parental smoking and near-complete ascertainment of infants hospitalized with respiratory infection in the first 12 months of life.
