Rapid diagnosis of bacteremic pneumococcal infections in adults by using the Binax NOW Streptococcus pneumoniae urinary antigen test: a prospective, controlled clinical evaluation.
The diagnosis of severe pneumococcal infections is inadequate, relying heavily on culture of Streptococcus pneumoniae from blood or other normally sterile fluids, and is severely limited by prior administration of antibiotics. We evaluated prospectively the Binax NOW S. pneumoniae urinary antigen test, a rapid immunochromatographic assay, for the diagnosis of bacteremic pneumococcal infections in hospitalized adult patients. Antigen was detected in 88 of 107 cases overall, resulting in a test sensitivity of 82% (95% confidence interval [95% CI], 74 to 89%). Antigen detection was greater in those with pneumonia (67 of 77 [87%]) than in those without pneumonia (21 of 30 [70%]) (P = 0.04). Urinary antigen was also detected in 3 of 106 adult patients with community-acquired septicemic infections caused by other organisms, giving a test specificity of 97% (95% CI, 92 to 99%). For 45 pneumococcal bacteremia patients with a positive test on treatment day 1, urinary antigen excretion was monitored for the first week of antibiotic treatment. Antigen was still detectable in 83% (29 of 35 tested; 95% CI, 66 to 93%) on treatment day 3. Detection of urinary antigen is a valuable, sensitive, and rapid test for the early diagnosis of bacteremic pneumococcal infections in adult patients, even after antibiotic treatment has commenced.
Smith
Michael D
MD
Public Health Laboratory, Taunton and Somerset Hospital, Taunton, TA1 5DB, United Kingdom. mike.smith@tst.nhs.uk
Derrington
Petra
P
Evans
Rachel
R
Creek
Marjorie
M
Morris
Rhonwen
R
Dance
David A B
DA
Cartwright
Keith
K
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000942:Antigens, Bacterial / Q000652:urine*; D016470:Bacteremia / Q000175:diagnosis* / Q000382:microbiology; D002845:Chromatography; D006801:Humans; D007118:Immunoassay / Q000379:methods; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000175:diagnosis* / Q000382:microbiology; D011446:Prospective Studies; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D013296:Streptococcus pneumoniae / Q000302:isolation & purification*; D013997:Time Factors
D000942:Antigens, Bacterial; D011933:Reagent Kits, Diagnostic