![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](https://image.slidesharecdn.com/lec9-230531084500-8bd14b80/85/Lec-9-pdf-5-320.jpg)
Lec 9.pdf
- 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
- 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