Strategies for the prevention of pneumonia.

Pneumonia remains a major source of morbidity and economic cost to our society, despite the availability of new antibiotics for therapy. To truly reduce the impact of this illness, serious efforts at preventing infection must be undertaken. In the area of community-acquired infections, safe and effective vaccines are available against S. pneumoniae, the most common pneumonic pathogen, and influenza. High-risk individuals (Table 2), who should be considered for vaccination, include: the elderly; residents of chronic-care facilities; and patients with chronic cardiac, respiratory, renal, and hematologic illnesses. Influenza vaccine is effective in preventing infections in such high-risk populations, including the elderly. There is some controversy about the efficacy of pneumococcal vaccine in an at-risk population with severe co-morbid illness, but there is little doubt that the vaccine is effective in a more healthy elderly population. Both patients and physicians fail to appreciate the safety and utility of these vaccines as evidenced by their low rates of use. Remarkably, only about 10 per cent of appropriate persons have ever received the pneumococcal vaccine, even though it needs to be given only once in a lifetime. In the area of nosocomial pneumonia, several strategies for prevention have proven to be useful. Most promising is the use of topical antibiotics in the upper and lower airway. Although the efficacy of this approach is well established, its safety has been questioned in prior studies. For many reasons, this position should be reevaluated, and this therapy should be considered for use in carefully selected patients at risk, using modern techniques of aerosol therapy. Active investigation into vaccines against gram-negative bacterial look to yield promising results in the future. In addition, passive "serum" therapy with preformed antibodies is a strategy for preventing gram-negative lung infection that has shown use in animal studies and may circumvent certain logistical problems of vaccine therapy. Infection control methods and sensible handling of respiratory therapy equipment are simple, yet effective, means for preventing contamination of the airway in mechanically ventilated patients. Finally, for patients both in and out of the hospital, an understanding of the nature of host defense impairments leading to pneumonia will allow for strategies to boost host defenses.(ABSTRACT TRUNCATED AT 400 WORDS)