general concepts on tb infection control

12/12/13861 | اداره كنترل سل و جذام

نشست ساالنه برنامه كنترل سل

مازندران - بابلسر




General concepts on

TB infection control General concepts on

TB infection control




Transmission of TB

Hierarchy of Infection Controls

Administrative Infection Controls

Environmental Controls

Personal Respiratory protection

HCW protection

Presentation outlinePresentation outline




The purpose of infection control ProgramThe purpose of infection control Program

To reduce the risk of Mycobacterium tuberculosis transmission to health care workers, patients, and others in the health care facility




Mycobacterium tuberculosisMycobacterium tuberculosis

Generated by coughing, sneezing, speaking

Remains airborne and spreading air currents

Aerobic, desiccation-resistant

1-100 organisms may infect

Droplet nuclei, 1-5

Most exposed persons do not become infected




“At risk” health care worker“At risk” health care worker

Nurses

Physicians, specialists in internal medicine

specialists in respiratory medicine (extra risk providing bronchoscopy, caring ventilated patients in ICU)

Pathologists

Laboratory staff




Respiratory Protection

Administrative Controls


Fundamentals of Infection Control (1)Hierarchy of Infection Control

Fundamentals of Infection Control (1)Hierarchy of Infection Control




Prevention of droplet nuclei containing M. tuberculosis from being generated;

Prevention of TB exposure to staff and patients; and

Implementation of rapid and recommended diagnostic investigation and appropriate treatment for patients and staff suspected or known to have TB.

Administrative control measures

Administrative ControlsAdministrative control measures





Assign responsibility for TB infection control (IC)

Conduct TB risk assessment and develop written TB IC plan, including AII precautions

Ensure timely lab processing and reporting

Implement effective work practices for managing TB patients







Test and evaluate HCWs at risk for TB or for exposure to M. tuberculosis

Train HCWs about TB infection control

Ensure proper cleaning of equipment

Use appropriate signage advising cough etiquette and respiratory hygiene








Assignment of responsibilitiesAdministrative control measures

Assignment of responsibilities

Supervisory responsibility should be delegated to a specific person or infection control team with a leader

Should include experts in:

- infection control

- hospital epidemiology

- clinician

- engineering

IC team responsible for all aspects of the IC program





TB Risk Classifications (1)Administrative control measures

TB Risk Classifications (1)

All settings should perform risk classification as part of risk assessment to determine need for and frequency of an HCW testing program, regardless of likelihood of encountering persons with TB disease.







Low risk – Persons with TB disease not expected to be encountered; exposure unlikely

Medium risk – HCWs will or might be exposed to persons with TB disease

Potential ongoing transmission – Temporary classification for any settings with evidence of person-to-person transmission of M. tuberculosis







Inpatient Settings LowLow Medium

Potential Ongoing

Transmission

<200 beds<3 TB

patients/yr>3 TB

patients/yrEvidence of ongoing

transmission,regardless of setting

≥200 beds<6 TB

patients/yr>6 TB

patients/yr




Outpatient Settings LowLow Medium

Potential Ongoing Transmission

TB treatment facilities, medical offices, ambulatory care settings

<3 TB patients/yr

>3 TB patients/yr

Evidence of ongoing transmission,

regardless of setting








Implement effective work practices for managing TB patients Administrative control measures

Implement effective work practices for managing TB patients

Infection control plan (including TB) specific to each area within facility, and HCW group based on level of risk

Put all procedures in writing plan including:– Early detection isolation and treatment of infectious TB patients– Patient education– Decreasing of cough induction procedures

Administrative support for procedures in the plan, including quality assurance;

Educate staff about the plan - organization, rationale, and what is expected of them

TB screening program for health care workers

Education of patients and increasing community awareness; and

Coordination and communication between the TB and HIV programs.





Ensure early identification, diagnostic evaluation, isolation and treatment (2)


Ensure early identification, diagnostic evaluation, isolation and treatment (2)

Focus on high risk groups:– contacts,

– HIV+,

– positive medical history,

– People with social and epidemiologic factors)

Use appropriate diagnostic methods for TB/MDR-TB

Following Isolation protocols and procedures

Being sure about adequate effective treatment





Isolation proceduresAdministrative control measures

Isolation procedures

Designate high-risk areas (isolation rooms) for TB and MDR-TB patients or suspects

Establish rules and regulations for isolation (eg. Starting & interruption of isolation, target group, …)

Patient education, signed informed consent*




Second defense in TB IC program, after administrative controls,

Control of infection source

Dilute and remove contaminated air

Control airflow

Environmental ControlsEnvironmental Controls




UV lampsUV lamps

HEPA filters

Ventilation systems

Natural airflow


Technologies for removing or inactivating M. tuberculosis consist of Local exhaust ventilation, General ventilation

Air-cleaning methods, e.g., high-efficiency particulate air (HEPA) filtration, ultraviolet germicidal irradiation (UVGI)




Local Exhaust VentilationLocal Exhaust Ventilation

Source-control method for capturing airborne contaminants– Enclosing device: fully or partially enclosed source;

include tents, booths, and biologic safety cabinets (BSCs)

– External device: source near but outside enclosure

Should remove at least 99% of particles before next patient or HCW enters

Use – for cough-inducing and aerosol-producing

procedures




General VentilationGeneral Ventilation

Systems that dilute and remove contaminated air and control airflow patterns in a room

Single-pass system preferred for AII rooms

Maintain AII rooms under negative pressure– Existing settings: ≥6 air changes/hr (ACH)– New or renovated settings: ≥12 ACH

Recirculation (HEPA filtration, UV irradiation)

EngineersEngineers must look after function of ventilation system, to determine airflow and air exchange per hour




Ventilation AirflowVentilation Airflow

In places with highest risk of infection •TB isolation rooms;•Bronchoscopy rooms•Aerosol rooms•Sputum induction rooms•TB patient admission rooms• Bacteriological laboratory

wrong

Wright




Air flow measurementsAir flow measurements




Natural ventilationNatural ventilation




Air-Cleaning MethodsHEPA filters

Air-Cleaning MethodsHEPA filters

Use as supplement to ventilation

Used to filter infectious droplet nuclei from the air

Must be used– When discharging air from local exhaust ventilation booths directly

into surrounding room– When discharging air from an AII room into the general ventilation

system

Can be used to clean air that is exhausted to outside




HEPA FilterHEPA Filter

Use of filters Replacement of filter depends on: - volume and type of exposition - environmental condition - Airflow rate - type of filter - place of ventilation system




Air-Cleaning MethodsUVGI

Air-Cleaning MethodsUVGI

Kills or inactivates M. tuberculosis

Use as supplement to ventilation

Not substitute for negative pressure rooms

Not substitute for HEPA filtration when air recirculated from AII room into other areas

Emphasis on safety and maintenance

Occupational exposure limits:– Overexposure can cause damage to skin, eyes

– UVGI systems must be properly installed and maintained

UVGI - cleaningUVGI - cleaning




UVGI - measurements




Respiratory ProtectionGeneral

Respiratory ProtectionGeneral

Third level in the IC hierarchy

Should be used by persons– Entering rooms of suspected/confirmed TB patients– Around cough / aerosol-producing procedures– In settings where administrative and environmental controls will

not prevent the inhalation of infectious droplet nuclei

Decision on use of respiratory protection (RP) in labs should be made on case-by-case basis




Respiratory Protection (RP) Controls

Respiratory Protection (RP) Controls

Implement RP program

Train HCWs on RP

Train patients on respiratory hygiene




Respirators vs. MasksRespirators vs. Masks

Personal protective equipmentPersonal protective equipment




Periodic screening of health workers to detect disease at an early stage

Periodic screening of health workers to detect disease at an early stage

Each year for employees

Medical questionnaire

Chest x-ray, PPD test

Sputum exam if cough > 2-3 weeks

Special consideration for employees with increased individual risk

general concepts on tb infection control

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