1. Infection control of
tuberculosis
Fedorova S.V.

2. Infection control
• Tuberculosis infection control –
specific measures and work practices
that reduce the likelihood of the
MTB transmitting
• The basis of infection control is early
identification and adequate
treatment of infectious TB cases

3. Contact
interaction of at least two persons in limited
environment with noneffective ventilation
*

4. Intensity of TB contact
depends on
• Frequency of
interaction
• Time of interaction
• Distance of
interaction

5. 5
The principle of a stone in a pond *
Sourse
Spreading of TB infection
occasional contact [0.01%]
relatives/friends [10%]
family [30%]
* Veen, 1992

6. infective dose,
enters alveolas – it is the main
factor, can effect to risk of TB
transmitting
Risk of TB infection depends on

7. Infective dose
is defined
1. By concentration of lived MBT
in the air
2. Time of contact
* H. Rider, 1999

8. MYCOBACTERIUM TUBERCULOSIS
• Is released by pulmonary TB
patient during cough, sneezing,
singing, talking as small nuclei
• This nuclei spread in surrounded
environment by aerogenic way
• Large nuclei (> 140 µm) fastly set
down on different surfaces (as
home dust)
• Nuclei < 140 µm vaporize after 2´´
and form droplet nuclei (~ 5 µm)
with 2-3 МBТ
• Droplet nuclei 1-5 µm, stay in the
air and can circulate for several
hours or even days

9. On the photo we can see only
the largest nuclei
(aerosol)
from specimens of
pathological material
from a patient
 M. tuberculosis are present in the air as small drops of secret

10. 10 µm*
6-10 µm*
1-5 µm*
6% of inhalled droplet
nuclei enter alveolas
The size of droplet nuclei is the critical factor
defines infection!
*1 µm – 10-6 м

11. The number of droplet nuclei depends on situation
The
number
of
droplet
nuclei
0
10 000
20 000
30 000
40 000
50 000
Cough Talking Singing
Loudon RG, et al. Am Rev Respir Dis 1968;98:297-300
Cough – это главный признак,
indicates the likelihood of contagious case!

12. Cavity is present in lung
Destruction of lung
tissue defines the
contagious TB cases
The number of
lived МBТ may be
until
1.000.000.000

13. The process of MBT transmitting among
population without HIV-infection
Aerosol
in the air
Risk
of TB infection
Latent TB infection*
Noninfected persons
TB during 5 years
(5%)
TB after 5 years
(5%)
Healthy infected
persons (90%)
*Latent TB is not disease. Latent strains keep their
genetic properties as e. g. drug resistance

14. Risk of active TB development
after TB infection
• Risk factors:
• HIV (8-10% within a
year),
• Diabetes mellitus, other
concomitant diseases
and conditions

15. Risk of TB infection by other ways
(except aerosol)
 Books etc. no
 Bed-clothes no
 Dish no
 Floor, surface of table… no
 Infection throw the skin (contact way) theoretical
 Throw gastro-intestinal tract minimal risk
(during swallowing ) (1:10000 cases compare with aerogenic way)
 Throw respiratory epithelium POSSIBLE
(direct way during bronchoscopy)

16. Measures of infection control
Individual
measures
Environmental
control measures
Administrative control measures
IC management

17. Виды инфекционного контроля
Management of infection control – provides
the structural basis of infection control
realization
Administrative measures – to reduce
significantly the risk of TB transmission by
preventive generalization of droplet nuclei
Environmental measures – to reduce
concentration of droplet nuclei in
surrounded air
Individual measures – individual protection
of health care workers

18. Management of infection control
• Program coordinator
on infection control
• Planning of measures,
buildings etc
• Coordination and
communication with
the national and local
TB program

19. Administrative measures of infection
control
• Re-planning of buildings
• Early identification of TB patients
• Minimizing of time-spent in health care facilities
• Triage of people with TB symptoms and
separation of infectious cases
• Cough etiquette and respiratory hygiene
• To limit indications of procedures can cause
cough (inhalations, bronchoscopy etc)
• Early adequate treatment
• Education of health care workers
• Education of patients

20. TB patients’ separation
Patients
Diagnostic patients AFB(+) AFB(-)
microscopy
DS DR
MDR not MDR
XDR not XDR

21. Education of patients
• Respiratory hygiene
• Cough etiquette
• Using of individual and
surgical masks

22. Maximal limit indications of
procedures can cause cough
• Bronchoscopy (only in very serous indications
– operation, suspicion on oncological disease
etc.)
• Inhalations (only in cases of sputum induction)
• Spirography (only to investigate a patient
before operation)

23. Examination of health care workers
on TB
• During planed regular examinations (in high
risk zone – at least once within a year)
• By indications – appearance of clinical
symptoms, suspected on TB

24. Education of health care workers
Trainings, conferences
for health care
workers on TB
Include trainings for
health care workers
on infection control

25. Ventilation
Natural ventilation – natural air movement to achieve
dilution and air exchange in an area with free-flow of
ambient air (e.g., through the opened windows)
Mechanical ventilation – methods used to direct
airflow to dilute and remove air to produce negative
pressure in isolation room (e.g., window fan, exhaust
ventilation system)

26. VENTILATION – is very important
measure!
* Is necessary to
remove droplet nuclei
from the room air

27. Methods of ventilation
Natural ventilation Mechanical ventilation

28. Natural ventilation and furniture
Physician
Window
Door

29. Natural ventilation and furniture

30. Window fans

31. Ultraviolet germicidal irradiation
(UVGI)
• 205 - 315 nm (1 nm = 10-9 m)
• Kills or inactivates microorganisms (MBT)

32. Types of moveable ultraviolet
radiators

33. Wall ultraviolet radiators

34. Ceiling ultraviolet radiators

35. • Cloth masks
• Surgical masks
• Respirators
Personal respiratory protection

36. A little of history…
• 1346 – the first medical mask
(protection from «miasma»)
• 1848 – the first mask with valve for exhalation
• 1905–1920 – theory of airborne
transmission
• 1920 – wide using of masks
• 1980 – implementation of filtration standards and special
respirators

37. • Prevents the spread of
micro-organisms from the
wearer to others by
capturing the large wet
particles near the source
(the mouse)
• It does not provide
sufficient protection from
inhaling airborne infectious
droplet nuclei through
• Must be used by patients
Surgical mask

38. Respirators
• Special type of
closely-fitted
protection with the
capacity to filter
particles 1 micron in
size to protect from
inhaling infectious
droplet nuclei
• Must be used by
health care workers
in zone of high risk

39. You must see the number of filter (N95
N99 FFP2 FFP3) on respirator!

40. Correct technic of respirator
wearing

41. How should you
keep respirator?
41

42. • because people must not have a false sense of
security when waering the mask or the
respirator
42
Fit testing is important

43. Качественный тест с использованием угольной пыли
A little of history …

44. Qualitative
Based on quantitative measuring
of air volume, enter respirator
Quantitative
Fit test
Based on reaction of tested
person during introduction of
chemical substance

47. Thank you
for attention!