Passive smoking induces nasal biofilms in children

Objectives: Passive exposure of children to cigarette smoke has been implicated in several recalcitrant respiratory childhood disorders. However, to our knowledge, no information is available regarding the connection between passive exposure to tobacco smoke and the formation of nasal biofilms in children. The present study was therefore geared at investigating the hypothesis that exposure of children to household passive smoking may induce the formation of nasal biofilms. Methods: The study included 20 children between the ages of 6 and 12 years with a positive history of prolonged exposure to household passive smoke, and who required inferior turbinate reduction together with other procedures. Another 20 children who required similar surgeries but with negative history of exposure to household smoking formed the control group. None of children, in the study and control groups, had evidence of adenoids or infective rhinosinusitis. At the time of surgery, a tiny biopsy was taken from the lower border of the inferior turbinate. The specimens were processed for scanning and transmission electron microscopy. Results: The nasal mucosa of 11 out of 20 children with positive history of exposure to passive smoking showed biofilm formation. Ten of these biofilms grew S. aureus. On the other hand, only one child in the control group showed nasal biofilm. Longer exposure to tobacco smoke and higher urinary cotinine levels were associated with more frequent biofilm formation. Likewise, children of heavy smokers developed biofilms more frequently than other children. On the other hand, the age of the children and nasal allergy had no effect on the chances of biofilm formation. Conclusions: This is a preliminary report showing that children exposed to household passive cigarette smoking may develop nasal biofilms. Development of these biofilms may increase susceptibility of affected children to persistent sinonasal and possibly other respiratory infections.