Cigarette smoking and invasive pneumococcal disease

Smokers and people exposed to passive smoking have a higher-than-normal risk of developing invasive pneumococcal disease. Invasive pneumococcal disease is an infection caused by Streptococcus pneumoniae that is present in blood or cerebrospinal fluid. In a study of 228 patients with invasive pneumococcal disease, 58% were smokers compared to 24% of 301 healthy volunteers. This translates to a four-fold greater risk of invasive pneumococcal disease. Nonsmokers exposed to environmental cigarette smoke were twice as likely to develop invasive pneumococcal disease as people not exposed to passive smoke.