Etiology and treatment of pneumonia.

BACKGROUND: Lower respiratory tract infections are a common cause of morbidity among children. Among these infections pneumonia is the most serious illness and can be difficult to diagnose. The etiology of pneumonia is still partly unknown, primarily because of difficulty in obtaining adequate samples and lack of reliable diagnostic methods. ETIOLOGY OF PNEUMONIA: Streptococcus pneumoniae is recognized as an important cause of pediatric pneumonia regardless of age in both the inpatient and outpatient setting. In developed countries S. pneumoniae probably accounts for 25 to 30% of cases of pediatric community-acquired pneumonia. Viruses (mostly respiratory syncytial virus) are responsible for approximately 20% of cases, and Chlamydia pneumoniae and Mycoplasma pneumoniae occur commonly in older children. FUTURE CHALLENGES: Despite the effectiveness of antimicrobial therapy, the emergence of resistant bacterial pathogens has resulted in increased interest in developing more effective vaccines. If conjugate pneumococcal vaccines prove effective at eradicating carriage of pneumococci in the nasopharynx, immunization may be an important tool against the spread of pneumococcal disease. Future challenges include implementation of effective intervention strategies, production of simple diagnostic tools and development of effective vaccines.