Children exposed to second-hand smoke are more likely to get invasive meningococcal disease than children who are not exposed, according to a study from the Harvard School of Public Health. Chien-Chang Lee and colleagues also found a possible association of second-hand smoke exposure with invasive pneumococcal disease and Haemophilus influenzae type b.
By reviewing and analysing 30 case-control and 12 cross-sectional studies, the authors used the findings of all studies that had compared the occurrence of invasive bacterial disease in children exposed to second-hand smoke with its occurrence in children not exposed to second-hand smoke. The authors found that exposure to second-hand smoke doubled the likelihood of invasive meningococcal disease and although there was an increase in the risk of developing invasive pneumococcal disease and Haemophilus influenzae type b, this increase could not be distinguished from chance finding, perhaps because a relatively small number of studies were available. However, nasal carriage of N. meningitidis (which causes meningitis) and S. pneumoniae in children exposed to second-hand smoke was significantly increased compared to those who were not exposed. The effects were generally stronger in the youngest children, those below 6 years of age, who are more vulnerable.
These results suggest that by decreasing children’s exposure to second-hand smoke, deaths and illness caused by invasive bacterial diseases could be reduced.