This is about TB in India, for medical students and primary care doctors

1. TB in India:
Epidemiology and
Public Health Aspects
DR Shyam Ashtekar
Asst Professor, Community Medicine
SMBT Medical college, Nashik
shyamashtekar@yahoo.com
20 Nov 2015

2. Historical
• TB is a companion for humanity
from times of hominid ancestors
• 1882, 24 March-Robert Koch
found Mycobacteria TB
• Hence 24th March-World’s Stop TB
Day
• 1890-Tuberculin Protein-
diagnostic tool for TB infection
• 1895-X-ray invention made
diagnostics easy

3. In 20th Century
• 1921-BCG vaccine
• 1944-Streptomycin
• 1960-National Tuberculosis Institute of India
• 1962- National Tuberculosis Control Program
• 1992-NTCP review proved negative
• 1993-WHO made a Global Emergency call for
STOP TB
• 1997-Revised NTCP (RNTCP)
• 2005 RNTCP-Part of NRHM/now NHM
• 2016-17—back to daily regimen?

4. EPIDEMIOLOGY OF TUBERCULOSIS
Distribution of TB
Where, when, whom
Analytical aspects
Why, How, What is to be done for control

5. The Global Burden
• About 2 billion (200 crores) infected by TB
(world pop 7 billion) nearly 1/3rd pop infected
asymptomatically
• Estimated prevalence 6.5 cr (65 m) cases
• India and China share 50% global TB burden
• Annually incidence 8-10 m (1 cr) cases
• Annually, 90% cure
• 1.4 million deaths.
• Multi-Drug Resistance (MDR & XDR) and HIV a
dangerous combination

6. Global Map of TB

7. 7

8. 8

9. The Global TB Scene
• A global problem of poverty, poor living conditions
• Dramatic control with improvement of living
conditions
• Control also helped by BCG, streptomycin & INH
• But now a reemergence of TB
• HIV & TB a dangerous combination.
• Growing resistance to ATT
• Causes 7% of all deaths, 26% untimely deaths

10. Declineof Tb in Europebefore antibioticera

11. Drastic reduction of TB in developed
nations, but India ….
• Even before advent of TB
drugs, TB vanished as a public
health problem from Europe
and US.. With better living and
nutrition, workplace
conditions.
• In India, TB still is a big public
health problem despite best
anti TB drugs and diagnostic
tools.

12. A Brief History of TB control in India
1906 First TB Sanatoria 1906
1929 1929 India joins international union against TB
1949 1949 India Govt opens TB division
1944-1950 ATT drugs-SM, PAS, INH, Th
1951-65 Million children got BCG vaccination
1956 First estimation of TB cases: 8 million
1961-1978 NTP -ambulatory program in 390 (89%) districts
1083-86 Short course chemotherapy (SCC)
1993-2006 RNTCP with DOTS-biweekly
2006- WHO’s STOP TB
2017 Now daily regimen, dose with weight bands

13. No significant decline in TB in India
- See more at: http://www.tbfacts.org/tb-statistics-india/#sthash.B6wFATk6.dpuf

14. Burden of TB in India (2013 Park)
• Prevalence of Infection (30% pop), 40% infected by 14 Yrs
• Prevalence of all forms of TB, old and new: 2.1/1000 pop (26
lakhs in India)
• Annual incidence of TB infection by TST/PPD conversion is 15
per thousand.
• Annual Incidence of all TB cases : 1.7 cases/1000 pop (about
21 lakhs in India)
• Annual Incidence of new smear positive cases 0.75 /1000 pop
(75/lakh pop)
• Deaths due to TB--all India-2.4 lakh ( or 3.7 lakhs?)
• Total HIV +TB : 2.1 lakh (annual incidence 1.2 lakh)
• Case detection--all forms- is about 58%
• BUT MOST OF THESE ARE UNDERESTIMATES

15. India TB: Public Health Importance
• Leading infectious cause of death in country (3-4
lakhs per anum), >1000 deaths/day, 40/hr
• Kills adults, economically –productive members
• Great economic burden, >Rs 15000 crores
annually
• Great stigma attached. People tend to hide, deny
the problem
• 2% of new cases are MDR/XDR, hence 20000 per
anum
• The decline of TB is very small..negligible

16. India TB-worries and concerns
TB &
HIV link
dangerous
2% new cases are MDR
(N=20000),
Old & new MDR is 1.37
lakh accumulated cases
High Economic loss (annual
15000cr)-
Afflicts and kills working people-
2-5 lakhs annually
Silent chronic, often asymptomatic,
Highly infective. One open case is a risk to 15
new people annually

17. Epidemiology Triad
Agent
Host Environment

18. Agent factors
• Main type -Mycobacterium TB var Hominis
• Mycobacterium TB-Bovis- vet TB
• Atypical Mycobacteria-four subtypes
• TB bacteria may be fast or slow growers-decides future
course of disease. Slow growers tend to be dormant.
• May be intra or extra cellular
• Take Zeihl Neelson stain (but basically Gram+ve)
• Hardy-against weather, chemicals. But killed in sunlight.
• Tend to stay dormant in human body.
• Indian M-TB is milder than European TB.

19. Agent Factors..
• Genomes have been decoded for TB
mycobacteria. Lot of overlap in various types
• Highly infective bacilli, even 1-5 bacilli can infect.
• (An open case infects about 15 per anum)
• A smear +ve case, 1 cmm of sputum 1000-10000
bacilli.
• Exposure to bacilli infects 30-60% of exposed
people.
• Poor pathogenicity: Infection does not always
lead to disease.
• Efforts to identify clinical patterns to genomes.

20. Reservoir & Transmission
• Main reservoir is Human cases,
perhaps some role of cattle
• Infective material is TB
sputum/coughed out droplets. Case
remains infective for long.
• Becomes non-infective in 2 to 15
days after Short course
chemotherapy starts.
• Infection mainly through respiratory
route (or GIT)
• Main spread is indoor-to close
contacts, esp children
• Public spitting-dust particles inhaled-
less important

21. Host (Person) factors
Poverty-
undernutrition,
over crowding
Smoking,
Diabetes, can
predispose
HIV makes host 80
times more
susceptible
BCG gives
selective partial
immunity
Men>women
Main age
groups-
Childhood,
Young adult, old
age
Possibly cattle
handling
exposes to
some risk
Immunity –not
all infections
become disease
(only10%
become TB
disease)
Close contact
with open case

22. Age And TB prevalence
0
5
10
15
20
25
0-14 15-24 25-34 35-44 45-54 55-64 65+
2
21
23
20
16
11
7
Percentage
Age-wise TB cases -India 2006
% of TB cases

23. Natural History Of human TB
TB
droplet
infection
50-60% get
infected-
PRIMARY
COMPLEX-
detectable or
non-
detectable
(A) Healing in 95% cases
(calcified Ghon’s lesion)
May be Dormant
till old age/
lowered immunity
(B) Miliary TB
(C) TB
meningitis
(D) Post Primary
TB (reactivation
after
months/years)
Post Primary Lung TB
(90%)
Adult: Non-pulmonary TB
(spine, ovaries, meninges
nodes, skin, GI*) 9%
Dormant till old age/
lowered immunity
No
infection

24. Environmental factors
• Crowded habitations
• Poor localities, with poor
sanitation
• Indoor transmission to
contacts is most
important
• Public spitting is a lesser
threat

25. Larger Socio-Economic
Determinants (Risk Factors)
•Poverty, poor housing
•Urbanization, population
density
•Malnutrition
•Low-education

26. Disease forms
Pulmonary (PTB) 90% share
• Primary lung disease with regional
lymph nodes-(most children used to
get before BCG)-called PRIMAY
COMPLEX
• POST-PRIMARY PULMONARY TB-
Most common, usually a flare up of
primary complex or new infection in
adult life
• One third cases of PTB are infective
(lesion is open to bronchi)
Extra pulmonary
• Uncommon after
BCG coverage
• All organs were
affected-
meninges, Ovary,
uterus, spine,
bones, kidneys,
intestines, lymph
nodes, skin, joints

27. Clinical picture of PTB
Common/main features
• Cough for >2 weeks
• Fever-low grade
• Pain in Chest
• Hemoptysis (blood
-spit)
Other features
• Loss of appetite
• Loss of weight-
otherwise
unexplained
• Breathlessness
• Weakness
• Malaise

28. Clinical Detection is unreliable-PTB

29. Childhood TB
• About 10-20% total TB is childhood TB
• Age 1-4 years
• Often due to close contacts with TB patients
• Usually Pulmonary now, less of other organs
• But no sputum, hence difficult to diagnose
• Hence also does not transmit TB like adults
• Failure to thrive, Malnutrition-both underlying
cause and effect of TB
• Childhood PTB may spread to other organs
• Tuberculin test usually clueless because of prior
BCG vaccine, But a Mantoux test >10 mm is
assumed as diagnostic

30. Presumptive TB

31. Presumptive TB

32. Smear Microscopy

34. Tuberculin skin test (TST)
• Important diagnostic test world over (but not
India)
• PPD 0.1 ml intradermal on forearm skin
• Induration > 8 mm diameter is diagnostic, <6
non-reactive/negative, 6-8mm borderline.
• BCG or previous infection makes it unimportant
due to cell mediated immunity
• May be false positive or false negative.
• Hence useful only in children <2y in India

36. Debate on BCG
• Many objections regarding utility of BCG. Can
not give complete immunity against adult TB ,
the common PTB form
• Interferes with Tuberculin test as a diagnostic
tool
• BCG is not given in many countries (EU, US)
• But BCG’s main protection is against post-
primary extra-pulmonary forms of TB. Great
reduction in Extra-Pulmonary TB after BCG era.

37. Global picture of MDR

38. TB & HIV-Lethal partnership
• HIV depletes immunity, hence-
• People with HIV & TB INFECTION have 30% (80%)
chance of developing opportunistic TB DISEASE.
• HIV invites TB infection and flares up old TB -10% of
them in first year of HIV+ve.
• (Otherwise for PTB a lifetime chance of 10% relapse)
• Reinfection by TB is common in HIV+ve.
• HIV-PTB is often sputum negative-hence difficult to
diagnose, TT, Xray Chest often fails. Sputum culture or
better CBNAAT
• Spread of TB is faster in HIV infected contacts.
• TB disease is high in HIV patients, hence all TB
patients should get HIV test done.
• More potential for MDR XDR in HIV+

39. MDR (multi Drug Resistant) &
XDR (Extensively Drug Resistant)
• Drug resistant TB is a
new problem
• MDR is INH & Rifampicin
resistance
• XDR is Extensively Drug
Resistant TB--Resistant
to INH+R and also
second-line drugs.
• Diagnosis is by
sputum
microscopy that
continues to be
positive even after
4 months of SCC.
Now we use
CBNAAT
• Need for higher
drugs

40. Diabetes and TB
• Diabetes patients account
for 15-20% of PTB cases,
because weakening of
immunity
• All TB patients should get
screening for TB-sputum
test

41. Public Health Goal for TB..
Reducing prevalence of
U14Yr TB infection from
current 40% to <1%..hence
 Reduce/Eliminate
reservoir,
 Treat sources of infection
 Break the channel of
transmission by EDPT
 Protect susceptible
individuals (better
nutrition, BCG)
All PTB cases
+Cattle TB
Source
case
New
Host

42. Five levels of Prevention
5
Rehabilitation
4 Disability
Limitation
3 EDPT( Early Diagnosis &
Prompt Treatment)
2 Specific Protection
1 Health Promotion

43. Strategy in TB control-five
levels 5
Rehab
4 Disability
Limitation (by timely
and complete
treatment)
3 EDPT (mainly sputum
microscopy for symptomatic
persons & Treatment)
2 Specific Protection-mainly
BCG (partial success)
1 Health Promotion-through socio-
economics, nutrition, education-
RNTCP can’t do much effort here

44. TB CONTROL PROGRAM-RNTCP
Public Health measures

45. WHO’s Stop TB strategy
• Pursue high quality DOTS expansion &
enhancement
• Address HIV related TB, MDR, high-risk
groups
• Health system strengthening
• Engage all care providers-public & Pvt
• Empower people with TB, and
communities
• Enable and promote research

46. BCG vaccination
• High protection level for TB
health workers with BCG
vaccination is proven
• Protects for 15-20 years, or even
longer
• 0-80% of vaccinated community
protected, esp against childhood
TB, but not so much for adult PTB
• BCG offers only partial protection
• Can not be given in HIV cases

47. Diagnostics in RNTCP
Clinically suspected
• Chronic cough>2
weeks in adults
• Blood spit-
hemoptysis
Investigations
• Sputum microscopy-Usually Direct-
detects 80% cases in first test, 93% in
second test, 100% by third test
• Xray Chest (has only additional value)
• TT-Tuberculin Test, for child<2Y, or any
person with >20mm induration
• CBNAAT (cartridge based nucleic acid
amplification test) esp for relapse cases,
HIV+TB, MDR/XDR.

48. Short Course
Chemotherapy (SCC)
Evidence
• Domiciliary treatment is
equally or more effective
than hospital based
treatment (Chennai study)
• Isolation (to protect the
family) is not required with
SCC, and is fruitless by the
time of detection
• Peru and China have
demonstrated success with
DOTS approach

49. Treatment-old and new
Biweekly DOTS New daily regimen with call sign

50. New RNTCP
• India is shifting to daily regimen of SCC in 2017.
• Passive surveillance through all OPDs for TB cases.
• Diagnostics based on sputum AFB and CXR
• The dosage of drugs is based on for weight bands
• Only two categories (earlier we had 3 categories)
• MDR-XDR diagnosed with CBNAAT and managed with higher
drugs, nutrition support
• TB is a notifiable disease, but only 7% cases from private
sector are notified.
• Govt share of TB cases is only 50 %, rest goes to pvt sector.
Effort to reach out to pvt medical sector.
• Effort to detect and treat pediatric cases.

51. What defines ‘Control’ of TB
Infection Prevalence Rate
• When prevalence
of INFECTION in
children below
14Y is brought
under 1%
(currently 40%)
To do this..
• Reduce human
reservoir (cattle
reservoir?)
• Cut transmission by
improvement of living,
control spitting
• Protect susceptible
with BCG, (also better
nutrition)

52. The Indian Challenge of TB
• TB is a barometer of Socio-economic
situation -malnutrition, poor living
conditions
• High burden of chronic cases, high
infection rate, deaths, loss of work and
wages
• Targets of reducing TB burden not
achieved
• MDR, XDR, HIV are additional challenges
• Childhood TB needs attention.

53. The Global challenges for
elimination of TB by 2050
• Supply of funds for TB control at
global/national levels (nearly 60%
shortfall)
• Need for revolutionary technology for new
medicines, vaccines, diagnostic tests (esp
for latent infection),
• Genome research on TB may provide new
tools.
• Long way to go for elimination

54. 2 haunting questions for TB control.
Malnutrition
The issue of exposure to animal
TB

55. Thanks
Dr Shyam Ashtekar
SMBT Medical College, Dt Nashik
shyamashtekar@yahoo.com
20 Nov 2015
This PowerPoint is available on slideshare.com
http://www.slideshare.net/ShyamAshtekar/epidemiology-and-public-
health-aspects-of-tb-in-india