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Our tryst with Nucleic Acid Testing

Our tryst with Nucleic Acid Testing. Dolly Daniel, Dept of Transfusion Medicine, CMC, Vellore. A Large mission hospital > 100 years old Over 2200 IP beds Over 6000 OP a day About 75000 units of blood / components- annual usage Strong component of education / service and research.

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Our tryst with Nucleic Acid Testing

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  1. Our tryst with Nucleic Acid Testing Dolly Daniel, Dept of Transfusion Medicine, CMC, Vellore

  2. A Large mission hospital > 100 years old Over 2200 IP beds Over 6000 OP a day About 75000 units of blood / components- annual usage Strong component of education / service and research CMC, Vellore

  3. BB- Id Testing • Only Hepatitis B testing • 1988 – HIV • 1997 – HCV • All testing initiated before testing became mandatory for licensing

  4. Why NAT at CMC??? • Donor spread • Seropositivity • Anecdotal incidents of seroconversion

  5. The American Red Cross accepts blood donations only from volunteer donors. Among Red Cross donors in a given year, 19 percent donate occasionally, 31 percent are first-time donors, and 50 percent are regular, loyal donors.

  6. Detection of HIV-1 and HCV Infections among Antibody-Negative Blood Donors by Nucleic Acid–Amplification Testing -NEJM 2004 37,164,054 units screened Negative on serology 12 positive for HIV-1 RNA (1 in 3.1 million) (2 of which were detected by HIV-1 p24 antigen) 170 positive for HCV RNA ( 1 in 230,000) The respective rates of positive HCV and HIV-1 nucleic acid–amplification tests were 3.3 and 4.1 times as high among first-time donors as among donors who gave blood repeatedly Follow-up studies of 67 HCV RNA–positive donors demonstrated that seroconversion occurred a median of 35 days after the index donation Three cases of long-term immunologically silent HCV infection were documented

  7. Donor Profile Almost 70% are replacement donors In the West – 100% Voluntary Repeat donors? ?? Process of deferral / self deferral / temporary / permanent and attitudes - very different

  8. Linear Trend line

  9. Linear Trend line

  10. Issues • Patient Safety • (Staff requesting better ID screens) • Quality of blood products • One product being issued to even 5 babies

  11. . Eskimo: "If I did not know about God and sin, would I go to hell?" Priest: "No, not if you did not know." Eskimo: "Then why did you tell me?"” Annie Dillard

  12. The Indian Experience – IJMR Feb 2008

  13. India and NAT • Total no of samples: 12224 • Replacement donors : 8999 • Voluntary donors : 3225 • Seropositivity - 0.26% – HIV, 0.33% HCV, 1.12% HBV

  14. Seronegative but NAT positive • Yield - 8 / 12224 • Overall positivity – 1/1528 donations • HIV - 1/ 12224 • HCV / HIV 1 co infection- 1/12224 • HBV – 6/12224

  15. NAT testing would prevent • 3272 infectious transfusions • 818 HIV infected units • 409 HCV infected units & 2454 HBV infected units from being transfused. • If components are being processed – then double or triple these numbers

  16. Translation to the CMC scenario • Our donor distribution is very similar • We have about 27000 donors bled each year X 2 / 3 components • Approx 1/1500 transfusions infected • Therefore about 35 of our patients are being infected annually by TTIs. • (calculation of 2 components per donation)

  17. CMC Stats -2007-2008

  18. Institution • 3 years …….. • Justified • Negotiated • Presentations to clinicians

  19. The process • Challenges • Infrastructure and space requirements • Cost impact

  20. Assessments • Projected numbers of possible yields • Health technology assessment • Permitted on a trial basis

  21. "The trouble with jogging is that by the time you realize you're not in shape for it, it's too far to walk back." Franklin Jones

  22. The interim we waited….. • No substitute for repeat voluntary donors • No substitute for the practice of appropriate and rational use of blood

  23. The Numbers Total Donors Screened – 26500 Sero positives – 594 Sero Negative - 25906

  24. Seropositives • HIV – 51 ( 0.18%) • HBV – 364 ( 1.30%) • HCV –179 ( 0.67%) • Seropositive NAT Negative - 252 • HIV – 37 • HCV – 166 • HBV - 49

  25. Total seronegative units NAT positive – 68 Positive on repeat testing and discriminatory assays - 28 (0.105%) 1 per 950 donors approx)

  26. Spread of positives HBV 22 HCV 3 HBV & HCV 2 HIV 1

  27. One time positives and their significance? ? False positives ? Low viral loads – Poissonian distribution Follow up recommended ?

  28. Is it worth continuing? • Cost per prevented infection • At the cost of what?

  29. He who sleeps on the floor will not fall off the bed. Robert Gronock. .

  30. In the context of transfusion services • Has to be driven in the context of each individual institution • Accessibility missing …… NAT available • Basics of safe donor recruitment and appropriate use of blood and components

  31. To conclude • NAT seems to have worked for us… • The confirmation of NAT yields is worth following up • Working up samples which are one time NAT reactive – a must

  32. Above all • Each institution needs to thrash out the issue for itself • Imperative that simple and safety measures like repeat voluntary donor recruitment and rational use of blood be focused upon alongside

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