The presumptive etiologic diagnosis of pneumonia is based on epidemiological, clinical, radiologic, and lab data. Microbiological examination may also be done on sputum or endotracheal . . .
The presumptive etiologic diagnosis of pneumonia is based on epidemiological, clinical, radiologic, and lab data. Microbiological examination may also be done on sputum or endotracheal aspirates. The sensitivity and specificity of the Gram stain for identifying Streptococcus pneumoniae, however, is controversial. Reported sensitivity varies from 35% to 96%; specificity varies from 12% to 89%. The authors of this international study assessed the actual diagnostic value of aspirate Gram stain and sputum culture from 72 cases of bacteremic pneumococcal pneumonia in 70 patients.
Specimens were sent to the microbiology lab in 50 (69%) cases; 38 (76%) of these specimens were considered adequate for Gram stain report and culture. Gram stain was pot…