Rapid assays for the diagnosis of influenza A and B viruses in patients evaluated at a large tertiary care children's hospital during two consecutive winter seasons.
BACKGROUND
The rapid and accurate diagnosis of influenza facilitates antiviral therapy, judicious antibiotic usage, and cohorting patients to decrease nosocomial infection.


OBJECTIVE
To determine the utility of rapid influenza tests in a children's hospital.


METHODS
Two in vitro rapid immunochromatographic assays that detect and distinguish influenza A and B viruses were compared to the reference standard of viral culture.


RESULTS
In 9186 patients tested, overall sensitivity of the rapid assays for influenza A was 64.4% and specificity was 98.3%. Sensitivity and specificity were 28% and 99.9%, respectively, for influenza B. Overall sensitivity and specificity for Remel Xpect (2004/2005) were 47.7% and 98.7% for influenza A, and 20.3% and 99.8% for influenza B, respectively. Overall sensitivity and specificity of Binax NOW Flu A&B (2005/2006) were 78.3% and 98% for influenza A, and 35.9% and 99.9% for influenza B, respectively. The results for influenza B with both assays were significantly lower than previously reported and lower than stated in the manufacturer's package insert.


CONCLUSIONS
In a contemporary clinical setting, rapid assays for influenza displayed significantly lower sensitivities, especially for influenza B, than prior reports. Differences in pre- and post-licensure performance demonstrate the importance of continuous evaluation of rapid diagnostic tests for influenza.
Cruz
Andrea T
AT
Department of Pediatrics, Section of Infectious Disease, Baylor College of Medicine, Houston, TX, USA. atcruz@texaschildrenshospital.org
Cazacu
Andreea C
AC
Greer
Jewel M
JM
Demmler
Gail J
GJ
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D002845:Chromatography / Q000379:methods*; D006776:Hospitals, Pediatric; D006801:Humans; D007223:Infant; D009980:Influenza A virus / Q000302:isolation & purification*; D009981:Influenza B virus / Q000302:isolation & purification*; D007251:Influenza, Human / Q000175:diagnosis* / Q000821:virology; D011237:Predictive Value of Tests; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D013781:Texas; D013997:Time Factors; D014776:Virus Cultivation
D011933:Reagent Kits, Diagnostic