India is the highest TB burden country in the world & accounts for nearly 1/5th (20 per cent) of global burden of tuberculosis, 2/3rd of cases in SEAR. Every year approximately 1.8 million persons develop tuberculosis, of which about 0.8 million are new smear positive highly'- infectious cases.Annual risk of becoming infected with TB is 1.5 % and once infected there is 10 % life-time risk of developing TB disease

1. EPIDEMIOLOGY
AND
PREVENTION OF
TUBERCULOSIS

2. CONTENTS
 Introduction
 History
 Burden
 Epidemiological determinants
 Types
 pathogenesis
 Childhood TB
 HIV & TB
 Prevention
 Summary
 References
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3. INTRODUCTION
 Tuberculosis (TB) - Infectious bacterial
disease caused by Mycobacterium
tuberculosis - most commonly affects the
lungs.
 Transmitted from person to person via
droplets from the throat & lungs of people
with the active respiratory disease.
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4. HISTORY
 Consumption, phthisis, scrofula, Pott's disease,
and the White Plague are all terms used to refer to
tuberculosis throughout history.
 It is generally accepted that the microorganism
originated from other, more primitive organisms of
the same genus Mycobacterium
 Researchers theorize that humans first acquired it
in Africa about 5,000 years ago
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5. HISTORY
 Hippocrates, in Book 1 of his Of the Epidemics, describes the
characteristics of the disease: fever, colorless urine, cough
resulting in a thick sputa, and loss of thirst and appetite
 He notes that most of the sufferers became delirious before
they succumbed to the disease
 Hippocrates and many other at the time believed
phthisis to be hereditary in nature
 Aristotle disagreed,
believing the disease was contagious.
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6. CONT.
 1865- Jean-Antoine Villemin proved TB is contagious
 1882- Robert Koch discovers M.tuberculosis
 1884- First TB sanatorium established in U.S
 1943- Streptomycin- a drug to treat TB was discovered
 1943-1952- Two more drugs discovered to treat TB – INH &
PAS
 Mid 1970s- most TB sanatoriums in U.S closed
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7. FATHER OF MODERN TB
EPIDEMIOLOGY
 Karel Styblo, MD, (1921 – 13 March 1998) was born in
Czechoslovakia.
 Internationally renowned for his work with tuberculosis
(TB) - medical advisor to the Royal Netherlands
Tuberculosis Association - director of the International
Union Against Tuberculosis and Lung Disease (IUATLD) in
Paris from 1979
 Known as the “Father of modern TB epidemiology" and the
"father of modern TB control"
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8. BURDEN
 GLOBALLY
 In 2013, mortality of TB including HIV was 16 per
lakh cases
 Mortality of TB excluding HIV was 5 per lakh cases
 Prevalence of TB was 159 per lakh
 Incidence of TB was 80 per lakh
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9. INDIA
 India is the highest TB burden country in the world &
accounts for nearly 1/5th (20 per cent) of global
burden of tuberculosis, 2/3rd of cases in SEAR.
 Every year approximately 1.8 million persons
develop tuberculosis, of which about 0.8 million are
new smear positive highly'- infectious cases.
 Annual risk of becoming infected with TB is 1.5 %
and once infected there is 10 % life-time risk of
developing TB disease
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13. EPIDEMIOLOGICAL DETERMINANTS
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14. AGENT FACTORS
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 Agent
 Mycobacterium tuberculosis
- facultative intracellular
parasite, ingested by
phagocytes & resistant to
intracellular killing
 Source of infection
 Human - human case
positive for tubercle bacilli &
who has either received no
treatment or has not been
fully treated
 Bovine - infected milk
 Communicability
 Patients are infective as long
as they remain untreated

15. HOST FACTORS
 Age,
 Affects all ages
 In India, 0-14 age group – 2%
15-24 age group - 20%
 Sex,
 More prevalent in males
 Nutrition,
 Malnutrition – predisposes to TB
 Immunity,
 Man has no inherited immunity against TB
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16. Social factors
 TB is a social disease with medical aspects, also
known as barometer of social welfare
 Social factors include poor quality of life, poor
housing, overcrowding, population explosion,
undernutrition, lack of education, large families, &
lack of awareness of causes of illness
 All these factors are interrelated & contribute to the
occurrence & spread of TB
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17. MODE OF TRANSMISSION
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 Transmitted mainly by
droplet infection and
droplet nuclei – by
sputum-positive patients
with pulmonary TB
 Coughing generates the
largest number of
droplets of all sizes
 Frequency & vigour of
cough & the ventilation
of the enviroment
influence transmission of
infection

18. Incubation period
 Time from receipt of infection to the development of
a positive tuberculin test ranges from 3 to 6 weeks
 Development of disease depends upon the closeness
of contact, extent of disease & sputum positivity of
the source
 Incubation period may be weeks,
months or years
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19. TYPES OF TB
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 Pulmonary,
 In active cases – most commonly involves the lungs
(90% cases)
 Symptoms – Chest pain & a prolonged cough
producing sputum
 About 25% of people - asymptomatic
 Extra pulmonary,
 In 15–20% of active cases, the infection spreads
outside the lungs, causing other kinds of TB
 More commonly in immunosuppressed persons and
young children
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20. CONT.
 Extrapulmonary tuberculosis,
Common sites are
 Meninges
 Lymph nodes
 Bones & joints
 Intestine
 Genitourinary tract
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21. CONT.
 A potentially more serious, widespread
form of TB - "disseminated" TB - commonly
known as Miliary Tuberculosis.
 Miliary TB -10% of extrapulmonary cases
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22. PATHOGENESIS
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26. CLINICAL FEATURES
•Coughing that lasts two or more
weeks
•Coughing up blood
•Chest pain, or pain with breathing or
coughing
•Unexplained weight loss
•Fatigue
•Fever
•Night sweats
•Chills
•Loss of appetite
Signs and
symptoms
of active
Tuberculosis
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27. CHILDHOOD TUBERCULOSIS
 WHO estimates(2013) – Upto 80,000 children die from
TB each year & children account for over half a million
new cases annually.
 Estimated deaths only include – HIV-negative children
 Actual burden of TB in children is likely higher, especially
given the challenge in diagnosing childhood TB
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28. CONT.
 Children with TB,
 Poor families
 Lack of knowledge about the disease
 Live in communities with limited access to health services
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29. HIV & TB
 People living with HIV – 26 to 31 times more likely to
develop TB than persons without HIV
 TB - Most common presenting illness
 Among people living with HIV
 Among those taking antiretroviral treatment
 It is the major cause of HIV-related death.
 Sub-Saharan Africa – dual epidemic, accounting for
approximately 78% of the estimated burden in 2013
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30. COLLABORATIVE TB/HIV ACTIVITIES
 To address HIV-related TB, WHO recommends a 12 point
package of collaborative TB/HIV activities.
 Objectives,
 Reducing burden of TB among people living with HIV
 Reducing burden of HIV among TB patients.
 Implementation of these activities from 2005 to 2011 –
Saved 1.3 million lives
 Universal access to these life-saving measures must be
achieved & eliminate HIV-associated TB deaths
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31. MDR-TB
 Multi-drug-resistant tuberculosis (MDR-TB) is
defined as – tuberculosis that is resistant to at
least isoniazid (INH) and rifampicin (RMP),the
two most powerful first-line treatment anti-TB
drugs
 When the course of antibiotics is interrupted –
levels of drug in the body are insufficient to kill
100% of bacteria
 Spread from person to person as readily as drug-
sensitive TB and in the same manner
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32. CONT.
 Most commonly develops in the course of TB
treatment,
 Inappropriate treatment
 Missing doses or
 Failing to complete their treatment
 Multidrug-resistant strain can transmit TB if
pathogens are alive & patient coughing
 TB strains –often less fit & less transmissible &
outbreaks occur more readily in people with
weakened immune systems (HIV)
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33. PREVENTION OF DRUG RESISTANCE TB
Rapid diagnosis & treatment of TB:
• One of the greatest risk factors, especially in developing
countries
• If TB is identified & treated soon, drug resistance can be
avoided.
Completion of treatment:
• Previous treatment of TB is an indicator of MDR TB.
• Incomplete antibiotic treatment, or improper
prescription of antibiotic regimen – resistance can
develop.
• Drugs that are of poor quality or less in quantity,
especially in developing countries contribute to MDR TB
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34. Patients with HIV/AIDS should be identified & diagnosed as
soon as possible. They lack the immunity to fight the TB
infection & are at great risk of developing drug resistance.
Identify contacts who could have contracted TB: i.e.
family members, people in close contact, etc.
Much research and funding is needed in the
diagnosis, prevention and treatment of TB and MDR
TB
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PREVENTION OF DRUG RESISTANCE TB

35. EXTENSIVELY DRUG
RESISTANT
XDR-TB is defined as TB that has developed resistance
to at least rifampicin and isoniazid , as well as to any
member of the quinolone family and at least one of the
following second-line anti-TB injectable drugs:
Kanamycin
Capreomycin
Amikacin
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36. CONT.
 If TB bacteria are found in the sputum – diagnosis of TB can be made in a day or
two, but can’t distinguish bet. drug-susceptible & drug-resistant TB.
 To evaluate drug susceptibility, bacteria need to be cultivated & tested in a suitable
laboratory. Final diagnosis in this way for TB, & especially for XDR-TB, may take
from 6 to 16 weeks
 The original method used to test for MDR-TB & XDR-TB – Drug Susceptibility
Testing (DST).
 DST is capable of determining how well four primary ATT drugs inhibit the
growth of Mycobacterium Tuberculosis
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37. PREVENTION & CONTROL OF
TUBERCULOSIS
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38. Prevention & control
 Primary prevention- health education & specific
protection
 Population strategy & high risk strategy
 Secondary prevention- early diagnosis & specific
treatment
 Tertiary prevention- rehabilitation & disability
limitation
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39. PREVENTION & CONTROL OF TB
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 Early diagnosis and treatment,
particularly of sputum smear
positive cases – cornerstone of
tuberculosis control
 The Revised National
Tuberculosis Control
Programme (RNTCP) has
focused on achieving high cure
rates
 The protective efficacy of BCG
has ranged between 0 to 80% in
different studies

40. BCG-VACCINE
 The first human was vaccinated by the intradermal
technique in 1927
 BCG is the only widely used live bacterial vaccine. It
consists of living bacteria derived from an attenuated
bovine strain of tubercle bacilli
 The WHO has recommended the "Danish 1331" strain
for the production of BCG vaccine
 Since January 1967, the BCG Laboratory at Guindy,
Chennai, has been using the "Danish 1331" strain for
the production of BCG vaccine
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41. CONT..
 There are two types of BCG vaccine - the liquid
(fresh) vaccine and the freeze dried vaccine.
 For vaccination. the usual strength is 0.1 mg 0.1
ml volume. The dose to newborn aged below 4
weeks is 0.05 ml.
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42. RNTCP
 Need for a Revised Strategy
 India has had an on-going National TB Program, NTP
since 1962. Program reviews showed that only 30% of
estimated tuberculosis patients were diagnosed & treated
successfully.
 Based on the findings & recommendations of the review
in 1992, the GOI evolved a revised strategy and launched
the Revised National TB Control Programme (RNTCP) in
the country.
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43. COMPONENTS OF RNTCP
 The directly observed treatment, short-course
DOTS strategy along with the other ingredients of
the Stop TB Partnership are implemented as a
comprehensive package for TB control.
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44. FIVE PRINCIPAL COMPONENTS OF DOTS
Political and administrative commitment
Case detection by sputum smear microscopy
Uninterrupted supply of high-quality anti-TB drugs
Standardized treatment regimens with directly observed
treatment for at least the first two months
Systematic monitoring and accountability
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45. MANTOUX TEST
 The Mantoux test OR Mendel-Mantoux test OR the Mantoux
screening test OR tuberculin sensitivity test OR Pirquet test
OR PPD test for purified protein derivative-screening tool for
TB
 Tuberculin is a glycerol extract of the tubercle bacillus. PPD
tuberculin -precipitate of species-nonspecific molecules
obtained from filtrates of sterilized, concentrated cultures
 A standard dose is 5 tuberculin units (TU - 0.1 ml) is injected
intradermally (between the layers of dermis) and read 48 to 72
hours later
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46. CONT.
 The reaction is read by measuring the diameter of
induration (palpable raised, hardened area) across
the forearm (perpendicular to the long axis) in
millimeters
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47. CLASSIFICATION OF TUBERCULIN REACTION
The person's medical risk factors determine at which increment (5 mm,
10 mm, or 15 mm) of induration the result is considered positive.A
positive result indicates TB exposure.
5 mm or more is positive in
• An HIV-positive person
• Persons with recent contacts with a TB patient
• Persons with nodular or fibrotic changes on chest X-ray consistent with old healed TB
• Patients with organ transplants, and other immunosuppressed patients
10 mm or more is positive in
• Injection drug users
• Residents and employees of high-risk congregate settings (e.g., prisons, nursing homes, hospitals,
homeless shelters, etc.)
• Mycobacteriology lab personnel
• Persons with clinical conditions that place them at high risk (e.g., diabetes, prolonged corticosteroid
therapy, chronic malabsorption syndromes, etc.)
• Children less than 4 years of age, or children and adolescents exposed to adults in high-risk categories
15 mm or more is positive in
• Persons with no known risk factors for TB
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48. STOP TB STRATEGY
• DOTS expansion & enhancement
• Addressing TB/HIV, MDR - TB &
other challenges
• Contributing to health system
strengthening
• Engaging all care providers
• Empowering patients & communities
• Enabling & promoting research
STOP TB
STRATEGY
6 Major
components
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49. SUMMARY
 Despite all these national programmes & efforts from
govt of India , TB still continues to be a major socio-
economic burden of the country
 Still there is need to create awareness among health
care professionals, and the community
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50. REFERENCES
 WHO., Tuberculosis, URL available
http://www.who.int/topics/tuberculosis/en/ [Last
accessed on 20 feb 2015
 Park.K , Park’s Textbook of Preventive and Social
Medicine, 22nd ed. Jabalpur: Banarsidas Bhanot
Publishers;2013
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51. TAKE HOME MESSAGE
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