National Center for Biotechnology Information NCBI NLM MEDLINE humans pubmed abstract nih national institutes of health national library of medicine research support non-u.s. gov't adult female male adolescent aged middle aged Prospective Studies 80 and over sensitivity and specificity anti-bacterial agents / therapeutic use community-acquired infections / drug therapy community-acquired infections / microbiology pneumonia pneumococcal / microbiology haemophilus infections / diagnosis bacterial / drug therapy bacterial / diagnosis* bacterial / microbiology pmid:11049763 doi:10.1086/318151 b rosón j carratalà f gudiol community-acquired infections / diagnosis* gentian violet haemophilus infections / microbiology haemophilus influenzae phenazines pneumococcal / diagnosis sputum / microbiology* staining and labeling / statistics & numerical data