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TB: A Global Emergency

TB: A Global Emergency. 1/3 of the world (2 billion people) infected 1 person infected/second resulting in >30 million new infections, 8 million new cases Left untreated 1/3 die, 1/3 self-cure, 1/3 remain infectious TB kills 1 person every 10 seconds = 5000/day = 2-3 million each year. India

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TB: A Global Emergency

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  1. TB: A Global Emergency • 1/3 of the world (2 billion people) infected • 1 person infected/second resulting in >30 million new infections, 8 million new cases • Left untreated 1/3 die, 1/3 self-cure, 1/3 remain infectious • TB kills 1 person every 10 seconds = 5000/day = 2-3 million each year

  2. India China Indonesia Bangladesh Pakistan Nigeria Philippines South Africa Ethiopia Vietnam Russian Federation Congo Brazil Tanzania Kenya Thailand Myanmar Afghanistan Uganda Peru Zimbabwe Cambodia 22 High Burden Countries

  3. TB: Clinical Features • TB is caused by Mycobacterium tuberculosis • TB can affect any organ system: bone, kidney, CNS; 80% are pulmonary • Classic pulmonary systems of active disease: cough > 3 weeks duration, chest pain, bloody sputum • Classic systemic symptoms: fever, night sweats, weight loss, malaise • Treated for many years with long hospitalization, surgery, myriad of drugs leading to belief that TB is not treatable or treatment worse than disease.

  4. TB Infection vs TB Disease • TB infection – organism is present, but dormant, cannot infect others • TB disease – person is sick and can transmit disease to others if in lungs • 10% of individuals with TB infection will develop TB disease • Each individual with active TB can infect 10-15 people/year

  5. When does TB infectionbecome disease? • Most likely to occur in first two years after infection • If person becomes immunocompromised • HIV • Cancer • Chemotherapy • Poorly controlled diabetes • malnutrition

  6. The 5 Essential Components of the DOTS Strategy • Government commitment to a National TB Program • Priority to detect infectious cases by sputum smear microscopy • Standardized regimens of short-course chemotherapy, given under direct observation for , at least, the intensive phase • Regular, uninterrupted supply of anti-TB meds • Monitoring system for program supervision and evaluation

  7. 1. Political/Administrative Commitment • Perception of TB as a priority problem with real solution • Government acknowledges importance of disease • Public commitment to National TB Program (NTP) • Support for personnel, training, transportation, drugs

  8. 2. Accurate Diagnosis=Sputum Microscopy • Identification/cure of infectious cases (smear+) is highest priority of TB control • Smear+s 4-20 times more infectious; may infect 10-15/year; more likely to die if untreated • Timely results to reduce potential for transmission • Quality assurance/training--national reference lab is key

  9. Cough 3 weeks If 1 positive, X-ray and evaluation AFB X 3 If 2/3 positive: Anti-TB Rx Ifnegative: Broad-spectrum antibiotic 10-14 days If symptoms persist, repeat AFB smears, X-ray If consistent with TB Anti-TB Treatment Diagnosis of pulmonary TB

  10. Chest X-ray (CXR) as Diagnostic Tool • No CXR pattern is typical • Many TB cases are missed (10-15% culture+s) • Many non-TB cases misdiagnosed (40% diagnosed by CXR alone do not have active TB • Previous MD training emphasized CXR as best diagnostic tool • Often reaction to poor, inaccurate, or unavailable lab services

  11. X-ray-based evaluation causes over-diagnosis of TB Over- diagnosis NTI, Ind J Tuberc, 1974

  12. Microscopy is a more specific test than X-ray for TB diagnosis Specificity

  13. 3. Adequate Supply of Drugs • Treatment requires regular doses of combination regimens for >6 months • Identification of an adequate supply of appropriate drugs for patients prior to initiation of treatment essential • If regimens incomplete, real chance of development of drug-resistant strains which are hard or impossible to cure • Requires continuum of drug management services: selection,procurement, distribution, use.

  14. 4. Directly Observed Treatment • Why? Many patients don’t take medicines regularly, even if excellent health education provided • Who? All patients... impossible to predict which patient will take medicine (1/3 not adherent) • What? Observer watches and helps patient swallow tablets • Where? Anywhere! (home, clinic, work, school, etc) • Who does it? HCW, community liaisons, teachers, Direct observation ensures treatment for entire course with the right drugs, in the right doses, at the right intervals

  15. DOT is necessary even when drug supply ensured Treatment Success No DOT DOT Chaulk CP. JAMA 1998;279:943-8

  16. DOT prolongs survival of HIV-infected TB patients SCC with DOT SCC without DOT

  17. 5. Systematic Monitoring/Accountability TB Register • Recording system is simple to use, essential, integrated component of DOTS enabling • Monitoring of patient outcomes • Evaluation of program performance • Analysis of epidemiologic data • Identification of areas for OR • Every level of health system accountable for patient diagnosis and cure; “report card”

  18. TB and HIV/AIDS • HIV negatively impacts TB and TB negatively impacts HIV • HIV+ individuals infected with TB are 30x more likely to develop TB disease • TB is leading cause of death among HIV+, accounting for ~40% of AIDS deaths • HIV increases the prevalence of active TB in HIV- and HIV+ populations

  19. Multidrug-Resistant TB (MDRTB) • Defined as resistance to INH and RIF • Caused by inconsistent or partial treatment of susceptible TB (primary) • Cure rates <70% cause the epidemic and drug resistance to increase • Drugs are more toxic and expensive, and less effective; treatment more difficult/expensive, and more likely fatal in developing world • Poorly supervised, incomplete treatment is worse than no treatment at all: Prevention of MDRTB is the primary strategy to address MDRTB

  20. USAID TB Strategy • Support for the STOP TB Initiative • Establishment of field sites/programs to serve as models for innovative wide-scale TB control • Investigation/implementation of potential technologies and methodologies for TB prophylaxis, diagnosis, and treatment • Support for surveillance to monitor TB trends and identify MDRTBstrains before they become widespread

  21. USAID Expanded Response • Continued investments in global and regional partnerships: • support for the Stop TB initiative • continued work with other USG agencies • Global partnership to develop new anti-TB drugs • Global Drug Facility • New International coalition of organizations and agencies including KNCV, IUATLD, WHO, CDC, ALA/ATS to provide TA/develop TB expertise • Continued support for coordinated research to optimize diagnostics and treatment regimens

  22. USAID Expanded Response • Expanded research investments • rapid and sensitive TB diagnostic tests • increase funding, work with our partners to mobilize efforts and expertise of PH workers, industry, academic researchers, donors, other partners in lab/OR components • Target collaborative efforts to develop cost-effective TB drugs and combination therapies • Potential expansion to vaccine development

  23. USAID Expanded Response • Focused, expanded programs in key countries, targeting • countries of greatest need, defined by TB burden • countries with high HIV/AIDS prevalence • countries at risk of escalating MDR epidemics

  24. Partners/Implementers • Current • WHO, CDC, Fogarty/NIH, IUATLD, Gorgas Institute, MSH/RPM, PATH, QAP, FHI • TBCTA (TB Coalition for Technical Assistance) • Potential • NGOs (MSF, DOW, MERLIN) • Foundations, World Bank, US Model Centers

  25. Global Programs/Mechanisms • Global/Bureau umbrella agreements with WHO and CDC • Multiple agreements to address technical areas: RPM, PATH, TBCTA • New interagency alliances under development for drug procurement/ management/development • Standard indicators already developed

  26. Common Health Assumptions not applicable to TB • Access is necessary but NOT sufficient • Drugs • Services • Not every health center/NGO site appropriate as TB care center • Poor program is worse than no program at all

  27. Priorities of TB Control • Make sure the person completes TB treatment! • Do not cause drug resistance; a poor TB program is worse than no TB program! • Treating non-pulmonary cases and those infected without active disease are of lesser public health importance

  28. With TB, treatment is more than treatment, treatment is prevention

  29. Role of Rifampicin • Necessary for short-course treatment • Essential for at least first 2 months of regimens • Bactericidal for rapidly dividing and slow-growing organisms • Prevents emergence of resistance to other drugs • Intermittent treatment more effective than daily treatment in animal model; equally effective in clinical trials

  30. Role of Isoniazid • Mainstay of anti-TB treatment • Life saving in TB meningitis • Bactericidal for rapidly dividing organisms • Prevents emergence of resistance to other drugs • Intermittent treatment more effective than daily treatment in animal model; equally effective in clinical trials • Safe and effective for preventive treatment

  31. DOTS can reduce the TB burden Annual percentage decline in incidence/prevalence

  32. TB: the leading single infectious cause of death in SE Asia Number of deaths (1000s) Deaths from infectious agents in South-East Asia

  33. TB is a Leading Killer of Women Deaths among women

  34. Diagnosis of pulmonary TB • Patients with TB feel ill and seek care promptly • Active case finding is unnecessary and unproductive • Microscopy is appropriate technology, indicating infectiousness, risk of death, and priority for treatment • X-ray is non-specific for TB diagnosis • Serological and amplification technologies (PCR, etc.) currently of no proven value in TB control

  35. HIV Negative 70 60 Early HIV 50 40 Late HIV 30 20 10 0 Proportion of pulmonary TB patients with positive AFB smears AFB positivity in TB patients

  36. Prompt treatment of infectious cases reduces spread of TB • Smear-positive patients usually seek care • Smear-positive patients are 4-20 times more infectious • Untreated, a smear-positive patient may infect 10-15 persons/year • Smear-positive patients are much more likely to die if untreated Rouillon A. Tubercle 1976;57:275-99

  37. Severe Less Severe Lymph nodes Meningitis Pleural effusion (unilateral) Miliary Bone (excluding spine) Pericarditis Bilateral or extensive Peripheral joint pleural effusion Spinal Intestinal Severe and less severe forms of extra-pulmonary TB TB/HIV, A Clinical Manual, World Health Organization 1996

  38. Role of Pyrazinamide • Essential for 6- and 8-month regimens • No benefit if given > 2 months • Relatively ineffective at preventing emergence of resistance to other drugs

  39. Pyrazinamide essential for first two months of 6/8-month treatment Relapses Am Rev Respir Dis 1987;136:1339-42

  40. Role of Ethambutol/ Streptomycin • Prevent emergence of resistance to other drugs given • Hasten sputum conversion • Bacteriostatic or weakly bactericidal against rapidly dividing organisms

  41. Relapse rates low with directly observed treatment in both HIV(+) and HIV(-) patients Relapse rates Relapse (%) Am J Respir Crit Care Med 1996:154:1034-38

  42. Drugs Adverse reactions Peripheral neuropathy l Isoniazid Hepatitis l Gastroentestinal (anorexia, nausea, l vomiting, abdominal pain) Rifampicin Hepatitis l Reduced effectiveness of oral l contraceptive pill Joint pains l Pyrazinamide Hepatitis l Ethambutol Optic neuritis l Auditory & vestibular nerve damage l Streptomycin (also to foetus) Renal damage l Adverse reactions to anti-TB drugs

  43. CHOICE Quantification Financing USE PURCHASE Management of Stocks Information for user & for consumer Tender bids Order Quality Control DISTRIBUTION STORAGE Re-packaging Transportation Management of Drug Logistics Adequate buffer stocks must be maintained at national, state/regional, and local levels

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