Presentation on theme: "Increasing the predictive value of clinic- based rapid HIV antibody screening using oral fluid and whole blood testing in 10 NYC STD clinics, New York."— Presentation transcript:
Increasing the predictive value of clinic- based rapid HIV antibody screening using oral fluid and whole blood testing in 10 NYC STD clinics, New York City, 2006- 2007 Julia R. Cummiskey, MPH 1 Maushumi Mavinkurve, MPH 1, Rachel Paneth- Pollak, MPH 1, Jessica Borrelli, MPH 1, Alexis V. Kowalski, MPH 1, Susan Blank, MD MPH 1,2 1 New York City Department of Health & Mental Hygiene 2 Centers for Disease Control & Prevention
NYC STD Clinics The Bureau of STD Control operates 10 clinics across the five boroughs of New York City Services are free and confidential
NYC STD Clinics Services include: Testing and treatment for Syphilis, Gonorrhea, and Chlamydia HIV counseling and testing Hepatitis screening and vaccination PAP smears Emergency contraception
Rapid Testing, NYC STD Clinics Jan. 04 – Introduced rapid testing via finger-stick (FS) Mar. 05 – Replaced FS w/oral fluid (OF) rapid testing Nov. 05 – Documented cluster of false pos. OF tests Dec. 05 – Introduced FS as back-up for OF+* * OF+ : preliminary positive OF results throughout
Consequences of False Positive Cluster, Nov./Dec. 2005 Patients: undue emotional stress Staff: loss of time and resources to locate and notify non-cases Patients & staff: loss of confidence in testing services
Response to Cluster of False Positives, NYC, Dec. 2005 Revised testing algorithm to include FS rapid test for OF+ samples (same assay) Revised patient management algorithm accordingly
Whole-Blood (finger-stick) Whole-Blood (finger-stick)+ Rapid Oral Fluid HIV Antibody Test Oral-Fluid +Oral-Fluid - Finger-Stick Rapid HIV Test Finger-Stick +Finger-Stick - Confirmatory Testing (EIA / WB) or Conventional (EIA / WB) HIV Testing Algorithm, NYC STD Clinics, Dec. 2005
Rapid HIV Testing, NYC STD Clinics (2006) 53,169 OF rapid HIV antibody tests 497 (0.9%) OF+
Evaluation of Revised HIV Rapid Testing Algorithm Objective: Evaluate predictive value of using FS results to guide patient management
Evaluation of Revised HIV Rapid Testing Algorithm Methods: Compared results of FS rapid tests and Western Blot (WB) tests for patients with OF+ test results
OF Rapid HIV Testing, NYC STD Clinics, December 2005 – September 2007 97,653 OF rapid tests performed. 1,171 (1.2%) were OF+ 815 (67%) followed by FS rapid HIV test
FS Rapid HIV Testing, NYC STD Clinics, December 2005 – September 2007 815 FS tests performed 678 (83.2%) + 137 (16.8%) - All OF+ samples subjected to WB irrespective of FS results
Results of WB Tests, NYC STD Clinics, December 2005 – September 2007 678 Finger-Stick + 654 (98.1%) WB+ 13 (1.9%) WB –
Results of WB Tests, NYC STD Clinics, December 2005 – September 2007 137 Finger-Stick – 128 (99.2%) WB – 1 (0.8%) WB +
Positive Predictive Values PPV of OF test alone 920/(920+146) = 86.3% PPV of Finger-Stick following OF+ 654/(654+13) = 98.1%
Confirmatory WB Results for OF+ Tests With and Without FS Tests 795 OF+ tests, w/ FS 655 (82.4%) WB+ 271 OF+ tests w/out FS 265 (97.8%) WB+
HIV Testing Algorithm in Practice, December 2005 – September 2007 OF = Oral Fluid FS = Finger-Stick WB = Western Blot
Comparing FS Done & FS Not Done by Clinic December 2005 – September 2007
Comparing FS Done & FS Not Done by Gender and Behavior December 2005 – September 2007
Comparing FS Done & FS Not Done by Testing History December 2005 – September 2007
Lessons Learned Intro. of less invasive rapid HIV testing correlates with increased demand for testing. FS rapid HIV testing has applications for rapid OF HIV test quality assurance.
Lessons Learned Patient mgmt. can be guided by combined outcomes of 2 rapid tests. Significant differences appear between the individuals that got a 2nd rapid test and those who did not.
Post-Script Late 2007, revised algorithm permitted rapid detection of another cluster of OF false positives. We investigated and removed affected test lots from our clinics. We notified other recipients of agency- purchased test kits.
Acknowledgments Julia A. Schillinger, M.D., MSc. Preeti Pathela, DrPH Ellen J. Klingler, MPH Bernard M. Branson, M.D. Thomas A. Peterman, M.D., MSc. Special thanks to Jessica Borrelli, MPH!