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BENEFIT OF USING OF COPAN’S UNIVERSAL TRANSPORT MEDIUM (UTM) AND FLOCKED SWAB WITH THE BINAX NOW FLU A/B TEST SYSTEMS FOR REFLEX TESTING Abstract

Christine Biggs 1, Ron Lollar 2 The Chester County Hospital, Pennsylvania1; Diagnostic Hybrids, Ohio2

BENEFIT OF USING OF COPAN’S UNIVERSAL TRANSPORT MEDIUM (UTM) AND FLOCKED SWAB WITH THE BINAX NOW FLU A/B TEST SYSTEMS FOR REFLEX TESTING Christine Biggs 1, Ron Lollar 2 The Chester County Hospital, Pennsylvania1; Diagnostic Hybrids, Ohio2 Background: The use of cartridge tests for Influenza A & B has been steadily growing since their introduction. Specificity of these tests is often high, but sensitivity can vary depending on many factors leading to recommendations that all negative specimens also be tested by cell culture. The “gold standard” specimen for viral respiratory testing is a nasopharyngeal (NP) aspirate or wash. The use of standard NP swabs offers a convenience to the Clinician in collecting the specimen but is normally considered an inferior sample and often eliminates the ability to perform a reflex culture. A new collection device, a “flocked” swab (Copan Diagnostics Inc., Corona, California), was recently introduced. The design of the swab allows for collection and release of a greater amount of patient sample. This new design would allow the collection of the specimen by all the hospital staff. The use of the flocked swab combined with a 1-mL fill UTM would offer flexibility in testing by allowing both the rapid antigen tests and viral culture. Design/Methods: 278 Specimens were collected as follows: Gently pass the swab through the nose and into the posterior nasopharynx. Rotate the swab on the nasopharyngeal membrane 5-6 times and allow it to remain in place for 10-15 seconds. Remove the swab and repeat the procedure in the other nares. Remove the swab and snap it off inside the UTM-RT tube. The specimens were then transported to the lab for testing with the Binax NOW Flu A/B test. The residual specimen was frozen at -80!C until processed for cell culture. The viral culture was performed using R-mix Too™. Cultures were setup in duplicate in 48-well cluster plates and incubated for 40 to 48-hours. The culture for each patient was stained the D3 Ultra™ Screening Reagents. Positive specimens were identified further using the second cluster plate cells and individual monoclonal antibodies in the D3 Ultra™ kits. Results: The sensitivity /Specificity of the Binax Flu A were 73% and 99% and for Flu B 55% and 100% respectively. There were 11 co-infections detected only by culture. Conclusions: This evaluation compared the Binax NOW A&B™ and the rapid R-Mix Too cell culture using specimens collected with the Flocked swab and the 1.0-mL UTM. The results of the evaluation have confirmed the need for cell culture testing of negative cartridge tests. The low sensitivity of the cartridge confirms the recommendations for reflex culture. Collecting specimens with the flocked swab/UTM combination gives the Clinician ease of use while allowing for the highest quality test result. It is also important to note that during the evaluation we have isolated not only Influenza A and B, but a significant number of other co-infecting viruses that would have otherwise gone undiagnosed by relying solely on rapid cartridge testing for Influenza alone.

Methods Specimen Collection: Specimens were collected as follows: 1. Gently pass the swab through the nose and into the posterior nasopharynx. 2. Rotate the swab on the nasopharyngeal membrane 5-6 times and allow it to remain in place for 10-15 seconds. 3. Remove the swab and repeat the procedure in the other nares. 4. Remove the swab and snap it off inside the 1.0-mL UTM tube. 5. Transport the specimen to the lab for testing at ambient temperature.

R-Mix Too Positive Monolayers

Binax Procedure: 1. Vortex Flocked Swab and UTM. 2. Remove Binax device from pouch just prior to testing and lay flat on work bench. 3. Fill pipette by firmly squeezing the top bulb and placing pipette tip into sample. Release bubble while tip is still in sample. This will pull liquid into pipette. Make sure there are no air spaces in the lower part of the pipette. 4. SLOWLY (drop by drop) add entire contents of pipette (100-µL) to the MIDDLE of this pad by squeezing the top bulb. 5. Immediately peel off brown adhesive liner from the test device. Close and securely seal the device. 6. Read results in the window 15-minutes after closing device.

Conclusions: This evaluation compared the Binax NOW A&B™ and the rapid R-Mix Too cell culture using specimens collected with the Flocked swab and 1.0-mL UTM. The results of the evaluation have confirmed the need for cell culture testing of negative cartridge tests. The low sensitivity of the cartridge confirms the recommendations for reflex culture. Collecting specimens with the flocked swab/UTM combination gives the Clinician ease of use while allowing for the highest quality test result. It is also important to note that during the evaluation we have isolated not only Influenza A and B, but a significant number of other co-infecting viruses that would have otherwise gone undiagnosed by relying solely on rapid cartridge testing for Influenza alone.

R-Mix Too Culture Procedure: 1. 278 Cultures were inoculated in duplicate according to DHI’s product insert. 2. Cultures were incubated for 40-hours and a single monolayer was stained according to the DHI D3 Ultra Respiratory Screening and ID kit product insert. 3. Monolayers were examined for the presence of fluorescent cells. 4. Cell spots were prepared for positive specimens using the second monolayer and stained with the individual antibody blends.

Influenza A Results

Influenza B Results Binax Influenza B

Binax Influenza A

R-Mix Too Culture

Positive

Negative

Positive

50*

18**

Negative

1

209

R-Mix Too Culture

Positive

Negative

Positive

11*

9**

Negative

0

258

Sensitivity

73%

Sensitivity

55%

Specificity

99%

Specificity

100%

* 6 Co-infections: 3-Flu A/P3, 1-each Flu A/P1, Flu A/P2, Flu A/RSV ** 2 Co-infections: 1-Flu A/AD, 1- Flu A/RSV

Additional Isolated Viruses

* 2 Co-infections: 1-Flu B/P2, 1- Flu B/P3 ** 1 Co-infection: Flu A/RSV

Adenovirus

7

AD/PIV-1

1

PIV-1

2

AD/PIV-3

1

PIV-2

1

PIV-1/RSV

1

PIV-3

2

PIV-3/RSV

1

RSV

13

Benefit of Using of Copan's UTM & Flocked Swab with the Binax Now Flu A/B Test Systems  

http://www.dhiusa.com/upload_files/files/CVS2007_Biggs_Flocked_swab_UTM_Copan_0424.pdf

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