Parents who smoke put their children at risk of infectionsBMJ 2006; 332 doi: https://doi.org/10.1136/bmj.332.7542.628-e (Published 16 March 2006) Cite this as: BMJ 2006;332:628
Children whose parents smoke are at increased risk of certain infections due to the potentially virulent Streptococcus pneumoniae bacteria in their nose and throat, researchers have found. Infections include bronchitis, meningitis, pneumonia, and middle ear infections.
The research team, headed by David Greenberg, a paediatrician and infectious disease expert at the Soroka University Medical Centre in Negev, Israel, and colleague Noga Givon-Lavi, published their findings in Clinical Infectious Diseases (2006;42:897-903). The article will be accompanied by an editorial (p 904-6).
The researchers hope that their findings will persuade parents to quit smoking, especially when around their children (if not completely). “This should definitely encourage the parents not to smoke in the presence of their child, especially if this child has predisposing factors, such as asthma,” they said.
The team studied 208 babies from primary healthcare clinics in two Jewish and two Bedouin towns in southern Israel. They took nose and throat swabs from both babies and their mothers to determine carriage of S pneumoniae bacteria.
Forty five per cent of the children, aged 1-59 months, had two non-smoking parents. Pneumococcal carriage was 16% higher in children with exposure to smoking than in unexposed children. Exposed children were also more likely than non-exposed children to carry pneumococcal serotypes responsible for most of the invasive S pneumoniae disease. In addition, 32% of mothers who smoked carried S pneumoniae compared with 15% of mothers who were exposed to smoking and 12% of mothers not exposed to smoking.
Higher carriage rates of these pathogenic bacteria can translate into higher rates of infection, said Dr Greenberg, since carriage in the nose is the first step in causing disease. The team also found that compared with smokers, non-smokers carried more anaerobic bacteria, which actually interfere with the pathogenic bacteria in the nasal passages and throat.
The accompanying editorial commentary by Timothy Murphy of the University of Buffalo says that the study makes an important contribution to further our understanding of the epidemiology and pathogenesis of otitis media and notes that the team's link between smoking and a higher rate of pneumococcal colonisation in smoking mothers and their children explains, at least in part, the higher incidence of middle ear infection of the children of smoking parents.