PNEUMONIA

The attack rate of pneumonia increases with increasing age. About 14 p er 1000 adults >60 years old develop pneumonia each year. Risk factors for pneumonia include alcoholism, immunosuppressive therapy, heart di sease, age >70 years, large volume aspiration, presence of a swallowin g disorder and malnourishment. The 30-day mortality rate is about 15%, range 13.6 to 17.5%. Factors that are predictive of mortality are aty pical symptoms (poor eating, confusion, lethargy), neurological diseas e, current diagnosis of cancer, and recent or current use of antibioti cs. Streptococcus pneumoniae is the most commonly identified aetiologi cal agent; however, even in research studies, up to 50% of cases of pn eumonia are of unknown aetiology. Aerobic Gram-negative bacilli are mo re common as a cause of nursing-home-acquired pneumonia than in other settings; however, distinguishing colonization from infection is diffi cult. Empirical antimicrobial therapy for pneumonia is chosen on the b asis of the severity of the pneumonia, place of acquisition (home vers us nursing home) and knowledge of local antimicrobial resistance.