Use of a high-sensitivity rapid strep test without culture confirmation of negative results: 2 years' experience.
BACKGROUND
Optimal diagnostic management of patients with pharyngitis is controversial. In our study, we compared streptococcal complication rates at a large suburban medical center during 2 time periods: when pharyngitis patients were managed almost exclusively with throat culture and when they were managed primarily with a high-sensitivity antigen test without culture confirmation of negative results.


METHODS
Using a combination of Current Procedural Terminology and International Classification of Diseases, Ninth Revision codes, we studied all patients seen for either pharyngitis or known streptococcal complications during a 4-year period. We then reviewed all available charts of patients with known streptococcal complications for coding accuracy. We compared streptococcal complication rates during each -time period.


RESULTS
A total of 30,036 patients were seen for pharyngitis during the 4 years. A streptococcal diagnostic test was used in 66% of patient encounters. During the first 2 years (period 1), 99.9% of the tests ordered were blood agar plate throat cultures. During the second 2 years (period 2), 76.6% of tests ordered were high-sensitivity antigen tests without culture confirmation of negative results. Suppurative complications occurred in 37 patients in period 1 and 36 patients in period 2. There were no cases of acute rheumatic fever in either period. There was one case of poststreptococcal glomerulonephritis in period 2.


CONCLUSIONS
Use of a high-sensitivity antigen test without culture confirmation of all negative results has not been associated with an increase in suppurative and nonsuppurative complications of group A beta-hemolytic streptococci.
Webb
K H
KH
Biostar, Inc, Boulder, CO 80301, USA. kvwebb@biostar.com
Needham
C A
CA
Kurtz
S R
SR
D000038:Abscess / Q000382:microbiology; D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000942:Antigens, Bacterial; D001431:Bacteriological Techniques / Q000592:standards; D002648:Child; D003661:Decision Support Techniques; D005921:Glomerulonephritis / Q000382:microbiology; D006801:Humans; D007118:Immunoassay / Q000379:methods* / Q000592:standards; D008875:Middle Aged; D010612:Pharyngitis / Q000150:complications / Q000175:diagnosis* / Q000382:microbiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013290:Streptococcal Infections / Q000150:complications / Q000175:diagnosis* / Q000382:microbiology*; D013297:Streptococcus pyogenes / Q000276:immunology; D013997:Time Factors
D000942:Antigens, Bacterial