[Respiratory tract infections in the elderly, advances and limitations in the diagnosis and treatment].

Advances and limitations in the diagnosis and treatment of respiratory tract infections were discussed in relation to the prognosis of the elderly patients. Haemophilus influenzae and Streptococcus pneumoniae are the major pathogens in the community-acquired respiratory tract infections. On the other hand, methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa are the major pathogens in the nosocomial respiratory tract infections. Detection of MRSA-PBP genes and antibiotic sensitivity tests are important for the diagnosis of MRSA. Vancomycin or arbekacin is the first-choice antibiotic for the treatment of severe infection caused by MRSA, and a combination therapy using one of the above agents and a partner antibiotic is necessary in some cases of MRSA infections. Reports concerning the significance of anaerobic bacteria in respiratory tract infections in Japan have been rare, presumably because procedures to recover anaerobic bacteria from specimens other than sputum, for example transtrancheal aspiration (TTA), bronchoscopic procedure and transcutaneous lung biopsy, are required for the diagnosis of the anaerobic respiratory tract infections. Nowadays, identification of cytomegalovirus (CMV) is a prerequisit for the rapid diagnosis of CMV infection. Therefore attempts are being made to detect a specific substance, for example messenger RNA during the stage of reactivation of CMV. Prophylaxis as well as treatment is necessary for the control of acute exacerbation of chronic respiratory tract infections. In this regard, long-term administration of a small dose of erythromycin or new-quinolone is promising.