Tuberculosis Control Dr. Yeşim YASİN Fall-2013. Outline What is Tuberculosis (TB)? Burden of TB,...
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Transcript of Tuberculosis Control Dr. Yeşim YASİN Fall-2013. Outline What is Tuberculosis (TB)? Burden of TB,...
Tuberculosis Control
Dr. Yeşim YASİN Fall-2013
Outline
• What is Tuberculosis (TB)?
• Burden of TB, TB/HIV, MDR-TB
• Strategy, targets, progress
• Prevention and Control Programmes of TB
• Challenges towards elimination
2
What is TB?
• One of the oldest diseases known in the
history.
• It is a preventable and a curable disease if
detected and treated early.
3
4
Prevelance of infection
• About one-third of the world‘s population is
infected with TB bacilli
people have been infected by TB bacteria
but are not (yet) ill with disease and cannot
transmit the disease.
5
• After a healthy person with a healthy
immune system breaths in TB bacteria, he
or she will have 10% lifetime chance of
developing TB.
• Immune-compromised persons have a
much higher risk of falling ill. 6
active TB (disease)
delays in seeking care/diagnosis/treatment
results in transmission of the
bacteria to others7
People ill with TB (active case)
can infect up to 10-15 people
through close contact over the
course of a year
• Without proper treatment
up to two thirds of people
ill with TB will die. 8
Natural history of TB
Factors
Agent factors
Host factors
Social factors
9
Agent Factors
AgentSource of infection communicability
TB bacilli have a thick waxy coat,they are slow growing and they can survive in the
body for many years in a dormant or inactive state whereby people are infected but
show no signs of TB disease.
The most common source of Tuberculosis infection is
the human case whose sputum is positive for the tubercle bacilli, and who
has either received no treatment for it or not got treated fully. Such sources can discharge the bacilli in
their sputum for years
Transmitted by droplet nuclei
10
Host factors
Host Factors
All age groups
Males>Females Nutrition İmmunity
Host susceptibility is universal, but the risk of infection is directly and mainly related to the degree of exposure.
After 20 years of age, TB tends to affect more males due to higher exposure to infection and higher prevalence of risk factors.
People who are co-infected with HIV and TB are 21 to 34 times more likely to become sick with TB
11
Social factors
Social Factors
Population explosion
Over-crowded
living con.
Under- nutrition
Lack of education
12
Incidence of some selected infectious diseases by years
(per 100000 population), Turkey
Health statistic year book 2010
13
2011 Data-Turkey• Incidence: 24/100K (WHO estimate)• Patients in total: 15.679 (21/100K) registered• Patients in total in Istanbul: 4.898 (36/100K) registered• New cases in Istanbul: 4.457 AFB+ patients: 1.794
(registered)
14
TB mortality risk factors
• Site (higher in positive smear)• Type of disease (association to…)• Timeliness of diagnosis and treatment• Appropriate diagnosis• Mistake in reading X-rays• Mistake in interpreting signs and symptoms
• Timely/Delayed diagnosis• Timely/Delayed treatment• Quality of treatment
Why worry about TB?
16
Some facts• TB is the second (only to HIV/AIDS) greatest killer worldwide due to a
single infectious agent.
• 8.7 million new cases in 2011; 13% is co-infected with HIV
• 22 high-burden countries account for 80% of the world’s TB cases.
• 1.4 million people died: 430.000 were HIV+
• Almost 60.000 people worldwide lives with MDR-TB
• The largest number of new TB cases occurred in Asia, accounting for
60% of new cases globally
• Funding is inadequate
17
Estimated number of cases
• 8.7 million (8.3-9.0 million)• 1.1 million (13%) (1.0-1.2 million)• Up to 0.5 million
Estimated number of deaths
• 1.4 million (1.3-1.6 million)• 430,000 (400,000-460,000)• Unknown, but
probably>150,000
18
All forms of TB
HIV associated TB
MDR-TB
Incidence rates, 2011
19
TB cases, deaths, 1990-2011
20
Incidence Mortality
All cases
HIV+ cases
Peak > 9 million in early 2000s, 8.7 million in 2011
Total mortality peaked early 2000s at >1.8 million 1.4 million in 2011
HIV+ mortality
millions
TB/HIV Coinfection80% of all TB/HIV cases are in Africa TB leading cause of death in PLHIV: ¼ of PLHIV worldwide die due to TB. PLHIV infected with TB: 20-40 times more likely to develop active TB. Untreated, TB in PLHIV leads to death in weeks 21
Distribution of MDR-TB among new TB cases, 1994-2011
22
Number of MDR-TB cases, 2011
23
Russian Federation 44,000 (14% of global MDR burden)
China61,000 (20% of global MDR burden)
India66,000 (21% of global MDR burden) South Africa
8,100 Based on survey data
Pakistan 10,000 (3% of global MDR burden)
Ukraine 9,000 Based on survey data
To date, 84 countries that reported XDR-TB
24
About 9% of MDR-TB cases are XDR
• 1. Pursue high-quality DOTS expansion
• 2. Address TB-HIV, MDR-TB, and needs of the poor and vulnerable
• 3. Contribute to health system strengthening
• 4. Engage all care providers • 5. Empower people with
TB and communities • 6. Enable and promote
research 25
Goal 6: to have halted by 2015 and begun to reverse the incidence…
2015: 50% reduction in TB prevalence and deaths compared to 1990
2050: elimination (<1 case per million population)
Global progress on impact
• 51 million patients cured, 1995-2011
• 20 million lives saved since 1995
• 2015 MDG target on track: global TB incidence rate peaked in early 2000s
• BUT, TB incidence declining too slowly, 1.4 million people still dying, MDR-TB response slow, gaps in financing
26
27
Prevention and Control of TB
29A B
Risk and Prevention-1
1- Cough out TB particles - strength of cough (adults>>>children)
2- Live bacteria- smear + or culture +
3- Cavity30
Risk and Prevention-1
Risk and Prevention-2• Person A• Medication (DOT)• Isolation• <4 years• At night
• Surgical mask
• Person B• Space• Natural ventilation/fan• Air purifying respirator (N95)• Ultra Violet Germicidal Irradiation (UVGI)• High Efficiency Particulate Air (HEPA) Filter• Negative pressure
31
Risk and Prevention-2
TB CONTROL
•Detection and treatment of cases•Treatment of latent infection•Vaccination
32
TB Control
The three priority strategies for TB
prevention and control programs are:
• Identifying and treating individuals who have active TB.
• Finding and screening individuals who have had contact with
TB patients to determine whether they are infected or have
active TB, and providing appropriate treatment.
• Screening populations at high risk for TB infection to detect
infected persons and provide therapy to prevent progression
to active TB.33
Tuberculosis prevention and control
programs
• 1994 “Directly Observed Treatment, Short Course”
(DOTS) strategy
• each country to detect smear-positive TB cases
• offer standardized DOT ,
• with the objective of curing over 85% of TB patients.
34
DOTS
• Governmental commitment to TB Control• Reliable and continious supply of high-
quality Anti-TB drugs•Microbiologic confirmation of TB diagnosis• Supervision (DOT) of standardized short
course Anti-TB theraphy-at least during the initial phase• System for registration and follow-up
35
DOTS
What can DOTS do
• Increase treatment completion and cure rates• Reduce the emergence of drug resistant
TB• Improve cost-effectivenss of TB Control• Reduce TB incidence in conjunction with
other interventions.36
What can DOTS do?
Challenges
• HIV epidemic•MDR-TB, XDR-TB• Health system weakness and political will• Poor infrastructure and lack of support• Private practitioners• Prisons
37
Challenges
DOTS in Turkey
• Since 2003 Ministry of Health performed
pilot studies for DOTs (Directly Observed
Theraphy Short-course).
• In 2006 Tuberculosis Control Programme
was integrated to primary health care
system and DOTs is expanded in Turkey.38
DOTs in Turkey
DOT
• DOT can lead to reductions in
relapse and acquired drug
resistance
39
DOT
Tuberculosis Prevention and Control
Program in Turkey
• Main strategies include:
• BCG vaccination
• Case finding
• Effective chemotheraphy
• Health education
• Chemoprophylaxis
• Monitoring and evaluation system 40
BCG vaccination
BCG only at birth (or first contact with health services)
• This is the current recommendation of the EPI
(Expanded Program on Immunization) and the Global
Tuberculosis Programme and is the policy in our country.
• BCG protects against serious childhood forms of
Tuberculosis, such as TB meningitis and miliary TB.
• It may not protect to a high degree against adult
pulmonary forms of the disease.41
Case finding
• The aim is to reduce the transmission of TB by
screening high risk populations (eg. those at
an increased risk of exposure to TB infection,
most notably contacts of infectious cases) and
to detect and treat active disease earlier than
would otherwise occur. 42
Chemoprophylaxis
• Primary prevention
• Decrease incidence rate of TB
• By using Isoniazid (INH)
43
Chemoprophylaxis
Tuberculosis 1• Tuberculosis control and elimination
2010–50: cure, care, and social development
Knut Lönnroth, Kenneth G Castro, Jeremiah Muhwa Chakaya, Lakhbir Singh Chauhan, Katherine Floyd, Philippe Glaziou, Mario C Raviglione
44
Challenges to “elimination”
1. Commitment by governments and stakeholders fluctuating
2. Funding not secure; catastrophic costs for the poor un-resolved
3. Only 2/3 of estimated cases reported or detected 4. TB/HIV major impact in Africa 5. MDR-TB, with high burden in former USSR , China etc 6. Un-engaged non-state practitioners 7. Social and economic determinants maintaining TB 8. Research in need of intensification and investments
45
1- Lack of commitment
46
2- Funding
47
US
billi
ons
dolla
rs
Funding gap vs Global Plan ~ US$2–3 billion per year Funding gaps reported by countries US$0.7 billion in 2013
2013 2014 2015
3- The case detection/notification gap
• Global notifications Estimated incidence
• 3: The case detection/notification gap Nearly 3 million TB cases either not notified or not detected 481990 2000 2010
TB c
ases
(mill
ions
)3.7
7.88.7
5.8
GeneXpert
4985 countries using it by mid-2013
4- Responding to the TB/HIV epidemic
The WHO policy on collaborative TB/HIV activities
50
4- Responding to TB/HIV epi. through collaborative efforts
51
5- Responding to MDR-TB
The New England Journal of Medicine
MDR Tuberculosis — Critical Steps for Prevention and Control
Eva Nathanson, M.Sc., Paul Nunn, F.R.C.P., Mukund Uplekar, M.D., Katherine Floyd, Ph.D., Ernesto Jaramillo, M.D., Ph.D., Knut Lönnroth, M.D., Ph.D., Diana Weil, M.Sc., and Mario Raviglione, M.D.
52
Review Article
53
WHA resolution 2009 (22 May) includes all essential policies
6- Unregulated private sector• Private sector is first point of care
in many settings. India: 70% of people with cough go first to private practitioners
• Diverse network of formal and informal providers ranging from hospitals and corporate sector to the traditional healers and quacks
• Private sector engagement crucial in closing the gap on case detection
• Contribution to finding people with TB between 10%-40% in countries
• Collaboration exists but still not enough in many settings. Efforts need to be made on both ends
54
7- Alleviation of risk factors & soc-economic determinants
RR for active TB Weighted prevalence (22 HBCs)
Population attributable fraction
HIV infection 20.6/26.7 1.1% 19%
Malnutrition 3.2 16.5% 27%
Diabetes 3.1 3.4% 6%
Alcohol use (>40 g/day)
2.9 7.9% 13%
Active smoking 2.6 18.2% 23%
Indoor air pollution 1.5 71.1% 26%55
8- Intensive investments in R&D to develop new tools
56
Diagnostic Vaccine Treatment
Sputum smear microscopy BCG 1st-line TB drugs Discovered 1882 Developed 1920s Discovered 1943-1970
8- New tool pipelines in 2013
Diagnostics: • 7 new diagnostics or diagnostic methods endorsed by WHO since
2007; • 6 in development; • yet no Point of Care (PoC) test envisaged
Drugs: • 1 new drug (Bedaquiline) approved in late 2012, but probably little
impact on epidemiology; • 1 expected to be approved in 2013; • a regimen and other 2-3 drugs likely to be introduced in the next 4-7
years Vaccines:
• 11 vaccines in advanced phases of development; • 1 just reported with no detectable efficacy
57
8. Research as the key for elimination• 1.For elimination one would need rapid diagnostics at point of
care, potent short treatments, mass treatment of latent TB infection (TLTBI), and potent pre- and post-exposure vaccines. None is available today
• 2.Basic research is fundamental to gain further knowledge and R&D pipelines must be expanded, nurtured and well-financed
• 3.Increased financial resources for research: the need for research is estimated at 2 billion US$ per year; today, about 650 million US$ are invested.
• 4.Develop coalitions to maximize outcomes and ensure a continuum of research efforts so that basic science and R&D pipelines are informed by needs, and operational research allows rapid adaptation and introduction in high-burden settings
58
THANK YOU!
59