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Innovations in molecular diagnostics to enhance meningitis surveillance

Innovations in molecular diagnostics to enhance meningitis surveillance. Xin Wang Ph. D and Leonard Mayer Ph. D Meningitis Laboratory DBD/MVPDB/CDC. Meningitis epidemics in the meningitis belt of sub-Saharan Africa -the highest incidence (up to 1000 per 100, 000 population) in the belt

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Innovations in molecular diagnostics to enhance meningitis surveillance

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  1. Innovations in molecular diagnostics to enhance meningitis surveillance Xin Wang Ph. D and Leonard Mayer Ph. D Meningitis Laboratory DBD/MVPDB/CDC

  2. Meningitis epidemics in the meningitis belt of sub-Saharan Africa -the highest incidence (up to 1000 per 100, 000 population) in the belt -occur in cycles of 8-10 years during dry season -predominately caused by serogroup A meningococci; others SGs detected -MenAfriVac: an affordable serogroup A conjugate vaccine developed to eradicate A epidemics. Introduced in 2010 in 3 countries. http://www.meningitis.org/assets/x/53978

  3. Evidence-based vaccination strategies Prediction or early detection of epidemics and outbreaks Essential roles of laboratory in meningitis surveillance/control Assessment of vaccine impact/disease burden Rapid and accurate lab confirmation Monitoring of circulating meningococcal strains

  4. Methods for the detection of meningococcal disease

  5. “All LA true-positive cerebrospinal fluid samples showed the causative microorganisms by Gram stain.” • “Total patient charges were $175,000 ($7,954 per true-positive), with no detectable clinical benefit.” A Gram stain costs US$ 0.90 5,169 assays performed on 1,268 clinical specimens

  6. Development of real-time PCR assays: singleplex PCR

  7. Development of real-time PCR assays: multiplex PCR • Allows simultaneous detection of multiple targets / organisms in a single reaction • Conserves limited quantities of clinical specimens • Significantly reduces costs, such as reagents and person time • Important in resource-limited settings • Three multiplex assays have been developed (NmHiSp, BCY and AXW) • The sensitivity and specificity of the multiplex real-time PCR assays was indistinguishable from that of the singleplex real-time PCR assays

  8. Laboratory Assessment evaluate infrastructure identify needs Support for rt-PCR Testing Equipment Reagents/consumables Quality Control Internal and External Quality Control Proficiency Test Building real-time PCR capacity in African regions rt-PCR Trainings Lectures Lab practice Pre-/post tests Improve specimen collection/ transport Data management reporting Sustain rt-PCR Capacity Long-term mentorship Country ownership Partnership

  9. rt-PCR implementation in Africa Burkina Faso DRC Niger Ghana

  10. Burkina Faso--a successful example Enhanced Surveillance was implemented in 2003; Case-based Surveillance was implemented nationwide in 2010 to assess the impact of MenAfriVac Efforts being made to improve specimen collection, transport to a national reference laboratory for confirmation, and case-based data management and quality. Laboratory network at national level led by CHUP-CDG has been further strengthened in support of real-time PCR implementation and quality control The Bacteriology-Virology Laboratory CHUG-CDG  is a finalist for the ASLM Best Practice in Laboratory Medicine in Africa Award 2012 for “Use of real-time PCR for the detection of bacterial meningitis pathogens”

  11. Improvement of specimen collection and laboratory capacity in Burkina Faso n=254 n=800 n=3415 100%, 66%, 63%, 45% No. of cases No. of cases 94%, 0, 68%, 95%

  12. Real-time PCR confirmed more cases than other methods, 2010-2012 No. of cases tested R. Ouédraogo et al, unpublished data.

  13. Real-time PCR implementation in SURVAC countries Impact of real-time PCR should be evaluated when the number of CSF tested is significantly improved.

  14. Conclusions Simple, cost-effective molecular tools are increasingly used for disease diagnosis and surveillance. While challenges remain, implementation of real-time PCR at national level in Africa has been proven to be successful. rt-PCR improved meningitis confirmation in Burkina Faso; rt-PCR impact on laboratory capacity of other countries should be evaluated when the technology is fully operational and/or substantial number of CSFs being tested.

  15. Our vision for the future of African laboratories Enhanced laboratory capacity through real-time PCR implementation at national level to improve specimen testing in African countries. Strengthened inter-country laboratory network to promote scientific collaborations, to create training opportunities for laboratorian and to provide technical support between the countries. Essential roles of AFRO regional laboratories in reinforcement of laboratory capacity and improvement of laboratory quality control and quality assurance in these countries.

  16. Acknowledgement T H A N K Y O U ! Meningitis Laboratory and Epidemiology Team, MVPDB/CDC Burkina Faso Prof. Rasmata Ouédraogo Prof. Lassana Sangaré Dr. Absetou Ky Ba Dr. Ouangrawa Soumeya Dr. Abdoul Salam Ouedraogo Dr. Denis Yelbeogo Dr. Isaie Medah WHO partners (IST and AFRO) Partners of SURVAC countries

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