Contribution of a urinary antigen assay (Binax NOW) to the early diagnosis of pneumococcal pneumonia.
We evaluated the usefulness of a rapid urinary antigen test (Binax NOW; Binax) to detect Streptococcus pneumoniae for the early diagnosis of community-acquired pneumococcal pneumonia (PP) in 220 nonseverely immunosuppressed adults. We compared results of this test with those of sputum Gram staining. The rapid urinary antigen test showed limited sensitivity (65.9%; 95% confidence interval [CI], 51.4-80.4) but high specificity (100%; 95% CI, 99.7-100) for diagnosing PP. The test was more sensitive for patients with versus those without high-risk pneumonia (94% vs. 63%; P<.001) and for patients without versus those with demonstrative results of a sputum Gram stain (97% vs. 55%; P<.001), and it tended to be more sensitive for patients with versus those without bacteremic PP (92% vs. 74%; P=NS). Rapid urinary antigen testing permitted early diagnosis of PP in 26% more patients than did Gram staining but missed 22% of the rapid diagnoses initially identified by Gram staining. On the basis of our results, a sequential approach is proposed, with reservation of urinary antigen testing for high-risk patients for whom demonstrative results of a sputum Gram stain are unavailable.
Rosón
Beatriz
B
Department of Infectious Diseases, Hospital Universitari de Bellvitge, University of Barcelona, Barcelona, Spain. broson@csub.scs.es
Fernández-Sabé
Nuria
N
Carratalà
Jordi
J
Verdaguer
Ricard
R
Dorca
Jordi
J
Manresa
Frederic
F
Gudiol
Francesc
F
D000328:Adult; D000942:Antigens, Bacterial / Q000652:urine*; D006801:Humans; D011008:Pneumococcal Infections / Q000175:diagnosis*; D011018:Pneumonia, Pneumococcal / Q000175:diagnosis* / Q000382:microbiology; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D013296:Streptococcus pneumoniae / Q000302:isolation & purification*
D000942:Antigens, Bacterial; D011933:Reagent Kits, Diagnostic