Experience with the rapid Directigen test for influenza.
OBJECTIVE
To determine the sensitivity and positive predictive value of the Becton-Dickson Directigen AB performed on-site in a nursing home compared to viral culture.


METHODS
A 721-bed skilled nursing facility for veterans and spouses. DESIGN MEASUREMENTS: Nasopharyngeal specimens were obtained with a low clinical threshold from residents during 3 influenza seasons for rapid antigen testing in the nursing home. The specimens were then transported for viral culture by courier on ice to a laboratory 45 miles away.


RESULTS
A total of 327 samples were obtained; 36 were positive for influenza A by rapid test, and all but 2 grew the organism on tissue culture with a positive predictive value of 94%. Nineteen specimens were negative by rapid test, but grew influenza A on tissue culture with a sensitivity of 64%. Influenza prophylaxis was usually initiated the day the first positive rapid test was encountered when influenza was active in the community.


CONCLUSIONS
The Directigen AB is a reliable indicator of influenza when influenza has been culture-confirmed in the community. Although sensitivity is limited, a group of rapid tests provided early laboratory confirmation and facilitated the application of prophylaxis.
Drinka
Paul J
PJ
Wisconsin Veterans Home, King, WI 54946-0620, USA. Paul.Drinka@dva.state.wi.us
D000368:Aged; D000369:Aged, 80 and over; D016000:Cluster Analysis; D016358:Contact Tracing; D003428:Cross Infection / Q000175:diagnosis / Q000821:virology; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D007159:Immunologic Tests / Q000379:methods* / Q000592:standards; D017053:Infection Control; D009980:Influenza A virus / Q000276:immunology; D009981:Influenza B virus / Q000276:immunology; D007251:Influenza, Human / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control / Q000821:virology*; D008297:Male; D009305:Nasopharynx / Q000821:virology; D009735:Nursing Homes; D011159:Population Surveillance; D011933:Reagent Kits, Diagnostic / Q000592:standards*; D012621:Seasons; D012680:Sensitivity and Specificity; D013997:Time Factors; D014728:Veterans; D014776:Virus Cultivation; D014922:Wisconsin / Q000453:epidemiology
D011933:Reagent Kits, Diagnostic