hope in the pipeline: virtual implementation to assess new diagnostic tools

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Dr. Presented by Ivor Langley, Liverpool School of Tropical Medicine and Dr. Hsien-Ho, National Taiwan University

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43rd Union World Conference on Lung Health November 2012 J2J Lung Health Media Training

Hope in the Pipeline: Virtual Implementation to assess new diagnostic tools

Ivor Langley, Liverpool School of Tropical Medicine, UK Hsien-Ho Lin, National Taiwan University

Agenda Background Tuberculosis diagnostics - Some challenges and opportunities - How can modelling help? Virtual implementation What is it? - Operational modelling - Transmission modelling - Linking operational and transmission models Virtual Implementation Case Study from Tanzania Next Steps

Liverpool School of Tropical Medicine, National Taiwan University, and NTLP Tanzania

2

TB diagnostics some challenges and opportunities- the challenges for TB diagnosis ACCESS TO DIAGNOSIS Case detection is only around 45-80% in many parts of the world

McNerney R, and Daley P (2011), Towards a point-of-care test for active tuberculosis: obstacles and opportunities, March 2011 | Volume 9 www.nature.com/reviews/micro 3 Liverpool School of Tropical Medicine, National Taiwan University, and NTLP Tanzania

TB diagnostics some challenges and opportunities- the challenges for TB diagnosis

SPEED OF DIAGNOSIS Many visits required to provide sputum samples, receive diagnosis, and commence treatment Leads to high diagnostic default rate MDR-TB diagnosis will take a lot longer ~2-4 months

At end of intermediate phases if smear Positive Test For Drug Resistance and put on MDR -TB Treatment if found

Treatment Monitoring

TB Diagnostic Centre

Home

Becomes Sick with cough

Home

Return Home

At end of intermediate phases if smear negative

TB Cure

Health ClinicTB Suspect

Returning Every 2 wks for Medicines

TB Receive Treatment Diagnostic Medicine CentreTB Diagnosed

Home

TB Provide Diagnostic Sputum Centre Sample 1

Smear Positive

TB Diagnostic CentreSmear Negative

No TB Found

Return Home

Home

Home

Return Home

TB Diagnostic CentreReceive Diagnosis

HomeReturn Home

TB Diagnostic CentreProvide Sputum Sample 2

Liverpool School of Tropical Medicine, National Taiwan University, and NTLP Tanzania

4

TB diagnostics some challenges and opportunities- the challenges for TB diagnosis ACCURACY OF DIAGNOSIS Sputum Smear Microscopy only detects around 30 70% of TB cases Accuracy is much worse for HIV+ patients (typically 40% of cases) Secondary techniques such as chest x-ray and short course antibiotics treatment are likely to have high false positive rate 25-50%

Liverpool School of Tropical Medicine, National Taiwan University, and NTLP Tanzania

5

TB diagnostics some challenges and opportunities- hope in the pipeline The introduction and scale-up of new tools for the diagnosis of Tuberculosis (TB) in developing countries has the potential to make a huge difference to the lives of millions of people particularly those living in poverty e.g.

Ziehl Neelsen MicroscopySensitivity 35-75% Specificity 99-100% Turnaround 24-48hrs Cost per test $1.50 Time per test ~60mins Extra Investment nil

LED Fluorescence MicroscopySensitivity 40-80% Specificity 99-100% Turnaround 24-48hrs Cost per test $1.50 Time per test ~55mins Extra Investment $1,250

GeneXpert MTB/RIFSensitivity 80-95% Specificity 98-99% Turnaround

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