title: Cigarette smoking and infection.
abstract: BACKGROUND
  Infectious diseases may rival cancer, heart disease, and chronic lung disease as sources of morbidity and mortality from smoking. We reviewed mechanisms by which smoking increases the risk of infection and the epidemiology of smoking-related infection, and delineated implications of this increased risk of infection among cigarette smokers.
  
  
  METHODS
  The MEDLINE database was searched for articles on the mechanisms and epidemiology of smoking-related infectious diseases. English-language articles and selected cross-references were included.
  
  
  RESULTS
  Mechanisms by which smoking increases the risk of infections include structural changes in the respiratory tract and a decrease in immune response. Cigarette smoking is a substantial risk factor for important bacterial and viral infections. For example, smokers incur a 2- to 4-fold increased risk of invasive pneumococcal disease. Influenza risk is severalfold higher and is much more severe in smokers than nonsmokers. Perhaps the greatest public health impact of smoking on infection is the increased risk of tuberculosis, a particular problem in underdeveloped countries where smoking rates are increasing rapidly.
  
  
  CONCLUSIONS
  The clinical implications of our findings include emphasizing the importance of smoking cessation as part of the therapeutic plan for people with serious infectious diseases or periodontitis, and individuals who have positive results of tuberculin skin tests. Controlling exposure to secondhand cigarette smoke in children is important to reduce the risks of meningococcal disease and otitis media, and in adults to reduce the risk of influenza and meningococcal disease. Other recommendations include pneumococcal and influenza vaccine in all smokers and acyclovir treatment for varicella in smokers.
authors.affiliation: Clinical Pharmacology Unit, Kaplan Medical Center, Rehovot, Israel.
authors.forename: Lidia
authors.initials: L
authors.lastname: Arcavi
authors.forename: Neal L
authors.initials: NL
authors.lastname: Benowitz
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D001424:Bacterial Infections / Q000453:epidemiology* / Q000276:immunology; D015984:Causality; D004198:Disease Susceptibility / Q000276:immunology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012307:Risk Factors; D017678:Sex Distribution; D012907:Smoking / Q000009:adverse effects / Q000276:immunology; D016540:Smoking Cessation; D014029:Tobacco Use Disorder / Q000453:epidemiology* / Q000276:immunology*; D014777:Virus Diseases / Q000453:epidemiology* / Q000276:immunology