Title: TB Infection Prevention Control

[Image: TB control slide1]

[Image: Safety First]

- What is TB-IPC?
- Case study of healthcare-associated TB infection
- Risk of TB in healthcare workers (HCW)
- Determinants of TB infection risk
- Hierarchy of TB-IPC
- How to wear an N95 respirator

[Image: WHO]

- A combination of measures that cuts across disciplines & programs
- To minimize risk of TB transmission
- At an early stage worldwide with the first WHO policy in 2009

[Image: Safety without stigma]

[Image: Hospital]

A case of hospital acquired TB

[Image: Hospital]

A case of hospital acquired TB

History

A 3-month-old baby is admitted to paediatric ICU with severe respiratory distress.

TB is strongly suspected, but the baby has no household TB contacts.

His mother reports the baby was born prematurely at 29 week gestation, and spent 3 weeks in the kangaroo mother care ward.

She remembers sharing a room with another mom who looks sick and coughed continuously.

A possible TB source case?

[Image: Hospital]

A case of hospital acquired TB

[Image: Chest X-ray]

[Image: CT span shows lymph nodes obstructing right main bronchus]

[Image: Hospital]

A case of hospital acquired TB

[Image: Chest X-Ray]

Doctors manage to trace the potential adult source case. She is confirmed to be smear +ve for TB. Her M. tuberculosis culture is compared to the baby in ICU and is shown via molecular fingerprinting to be identical.

A contact investigation of 11 babies who shared the source case's room is done. Eight of the 11 babies are located, 4 have already been diagnosed with TB, including another mother. None of them had known community TB contacts.

Most likely TB acquired while in the hospital's kangaroo ward!

[Image: Hospital]

Question 1

Q: Transmission of tuberculosis (TB) can occur in healthcare facilities.
- True (correct)
- False
If chosen: Correct!

If chosen: Incorrect. TB can be transmitted in healthcare facilities.
Patients, healthcare workers, and visitors can be infected with TB through exposure to diagnosed and undiagnosed infectious TB patients in clinics and hospitals.

Two studies from South Africa:

Classens (2010):

TB research staff were 2.3 times more likely to get drug-sensitive TB than people in the TB-affected community they studied.

O'Donell (2010):

HCW are nearly 6 times more likely than the general population to contract MDR-TB; 4 times more likely to get XDR-TB

Annual Incidence | KZN HCW | KZN Population | Incidence Rate Ratio
MDR-TB | 62/100,000 | 10/100,000 | 5.8
XDR-TB | 4.5/100,000 | 1/100,000 | 4.3

[Image: Hospital]

Question 2

Please select the most correct answer

Q: Healthcare workers in high burden TB settings are:
- At significantly increased risk of acquiring TB from ongoing TB exposure (correct)
- At low risk of acquiring TB
- At the same risk of acquiring TB as the general population
- Protected from acquiring TB by the BCG vaccine
If chosen: Correct!

If chosen: Incorrect.
Healthcare workers are at a significantly higher risk of acquiring TB than the general population, due to ongoing exposure to infectious TB patients.

If chosen: Incorrect. Healthcare workers are at a significantly higher risk of acquiring TB than the general population, due to ongoing exposure to infectious TB patients.

[Image: X-ray]

What determines risk of TB infection?

1. Duration of exposure
2. Degree of exposure

- Number of live bascilli in the air
- Number of TB source cases
- Infectiousness of TB sources case(s)
- Frequency of air exchange (number of air changes per hour)

[Image: Hospital]

Question 3

Q: (Please select the best answer.)

The risk of TB transmission is determined by:
- Whether the patient has received the BCG vaccine in childhood
- Whether the index case shared eating utensils with exposed individuals
- The degree and duration of TB exposure (correct)
- Whether the index case is a healthcare worker
If chosen: Correct!

[Image: l'hopital]

Is drug-resistant TB more infectious?

MDR and XDR-TB are not more infectious than drug-susceptible TB.

However, in patients with drug-resistant TB there is

- A diagnosis of drug resistance
- A longer time to smear convert
- Longer hospitalisation

All of these factors increase the risk to HCW.

[Image: Hospital]

Question 4

Q: Which statement is correct regarding drug-resistant TB (DR-TB)?
- Convert to sputum smear-negative faster than succeptible TB.
- Is treated for the same duration as the regular susceptible TB.
- Is more infectious and communicable than the regular susceptible TB.
- Is more expensive and difficult to treat than drug susceptible TB. (correct)
If chosen: MDR and XDR-TB are not more infectious than drug susceptible TB. However, drug-resistance is often diagnosed late, patients take longer to smear conversion, patients are hospitalized for longer, and they are more difficult and expensive to treat.

If chosen: Correct!

[Image: TB culture]

Exposure to TB causes a latent TB infection.

Latent TB infection can lead to TB disease.

The lifetime risk of developing TB disease after latent exposure:

- in HIV-negative persons is 10%
- in HIV-positive persons is 5-10% per year

There is faster progression from latent TB to TB disease in;

- Immunocompromised people (cancer, HIV, steroids)
- Extremes of age (very young or very old)

[Image: Hospital]

Question 5

Q: A recognised risk factor for the development of the tuberculosis disease is:
- Female sex
- Frequent use of public transportation
- Asian race
- Extremes of age (very young or elderly) (correct)
If chosen: Incorrect.
Faster TB progression from latent TB to active TB disease occurs in immunocompromised people (e.g. HIV/cancer/steroid therapy), and extremes of age (very young or very old).

[Image: Administrative controls]

Administrative Controls

Aims of Heirarchy

Administrative | Reduce risk of exposure by an effective TB-IPC program
Environmental | Prevent spread and reduce concentration of TB aerosols
Respiratory Protection | Further reduce risk of exposure in special areas and circumstances

Adminstrative Controls

Everybody | Encourage cough etiquette & respiratory hygiene. Consider the possibility of TB in all patients.
Facility | Assign responsibility for TB-IPC. Perform TB risk assessments. Develop and implement TB-IPC plan.
Laboratory | Ensure timely processing and reporting of results.
Clincians | Implement effective management of TB patients (triage, isolation, treat promptly, discharge).
IC Team | Train HCWs aboiut TB-IPC, PPE use. Use appropriate signage for TB-IPC. Offer regular N95 respirator fit-testing for staff.
Occupational Health | Evaluate HCWs at risk for TB. Monitor and occupational TB stats.

Administrative Controls

Early diagnosis and treatment is essential.

[Image: Early diagnosis]

"Transmission Saturation"

Administrative Controls

What are the high risk areas for TB transmission?

Clinics

- Waiting rooms
- HIV clinics
- Sputum collection areas

Hospitals

- Adult medical wards
- Radiology
- TB laboratory
- Resus areas: intubations
- intensive care units
- Bronchoscopy
- Paediatric wards

Administrative Controls

Identifying high risk activity

Transmission Risk | Activity Profie
Patient-to-patient
Waiting areas | Smear+patients on treatment <2weeks
Open areas | Drug-resistant TB patients at follow-up
aTB suspects for work-up |
Patient-to-staff | Bronchoscopy suite Resuscitations/intubations Procedure rooms
Staff-to-patient | Delayed diagnosis of staff with TB

Question 6

Q: Which of these strategies is the most important in the heirarchy of TB infection control?
- Environmental controls
- Leadership controls
- Respiratory controls
- Administrative controls (correct)
If chosen: Proper implementation of the administrative controls will have the greatest impact  in reducing TB transmission in healthcare settings.

If chosen: Correct!

[Image: Environmental Controls]

Environmental Controls

Environmental controls in hospitals

- Bed spacing at 2.5 metres
- Curtains between beds
- Dry, easy-to-clean surfaces
- Sufficient hand washbasins
- Well-ventilated (natural or mechanical)
- Open spaces
- Central courtyards
- Recreation facilities

[Image: 2.5 metre bed spacing]

[Image: Courtyard]

Isolation Rooms

[Image: Isolation room]

[Image: Stop!]

Cough room

[Image: cough room ventilation]

[Image: cough room]

Small, confined space where patient goes to produce sputum.

Away from main clinical area.

Exhaust ventilation or open area.

Provision for hand decontamination

Clinics

[Image: Crowd]

[Image: crowd]

[Image: proper waiting area]

[Image: proper waiting area]

[Image: no]

[Image: yes]

Question 7

Q: (Choose the best answer.)

Environmental controls for TB:
- Should effectively treat patients with TB with correct anti-TB medications
- Should remove, replace, dliute or clean contaminated air (correct)
- Should provide clean, safe environments for patients with TB
- Should provide healthcare workers with protective equipment

Ventilation

Natural ventilation

[Image: Inadequate ventilation]

[Image: no]

This example shows inadequate ventilation.

[Image: Open courtyard plan]

[Image: Open porch]

[Image: yes]

This system utilises prevailing wind currents and temperature gradients but can result in patient discomfort.

Mechanical Ventilation

Prevents movement of TB-contaminated air to areas of susceptible people.

Includes:

- Desktop fans (positive pressure, directs airflow)
- Negative pressure: Extraction exceeds supply (at least 12 air changes per hour ACH)

[Image: mechanical ventilation]

Air flows inward from corridor into the negative pressure room and is sucked out via the exhaust.

Types of mechanical ventilation

[Image: Mechanical ventilation]

Controlled mechanical exhaust ventilation

[Image: Extractor fan]

Extractor fan (wall/ceiling mounted)

[Image: Roof vent]

Roof-mounted "whirlybirds"

Ultraviolet germicidal irradiation (UVGI)

An adjunct to ventilation | Units need regular servicing
Efficacy is controversial | Concerns about skin sensitivity
Alters DNA of TB cells; kill ration depends on time and intensity of UV expoure; specific UV wavelength required | Potential to cause skin cancers

[Image: UV unit]

[Image: Respiratory control]

Personal Respiratory Protection

[Image: Surgical masks]

For patients: Surgical masks only. N95 respirators exacerbate dyspnoea!

[Image: N95]

[Image: n95]

N95 respirators for HCW. (Reusable for up to 1 week.)

[Image: Surgical mask for HCW]

Surgical masks should not be used by HCW to prevent TB. (Only effective for +-15 minutes; single use only.)

When are you most at risk of TB exposure?

[Image: Sneezing]

- When patient is sneezing, coughing, shouting, crying
- At intubation / extubation / suctioning
- TB bacilli are aerosolised in a 3-metre radius
- TB aerosols can remain suspended for hours.

N95 Respirators

[Image: "Duckbill" type]

[Image: Cone/cup shaped]

[Image: Expiratory valve]

Originally designed for the painting industry. Filters out > 95% of particulate aerosols (vs. surgical masks 10-90% efficiency).

TB droplet nuclei 2-5 microns in size. The N95 can filter out particles 0.1-10 microns in size.

Cone/cup shaped

With expiratory valve

Duckbill type

How to don (put on) and doff (take off) an N95 respirator

[Image: Fitting]

[Image: Seal test]

[Image: Doff]

[Image: Wash your hands]

1. Open respirator, inspect for damage
2. Apply to face, adjust elastic bands/ties, pinch over nasal bridge
3. Perform positive pressure seal test
4. Perform negative pressure seal test
5. Remove respiratory touching the elastic bands/ties only, or use paper towel
6. Place respirator in labeled envelope and store
7. Wash hands with soap and water

How to reuse your N95 respirator

- Can be safely reused for up to 12 hours over 1 week
- Should be stored in a dry environment - i.e. envelope
- Make envelope with your name
- Do not store in plastic packets (moisture destroys the filter)
- Do not crumple of fold, as this destroys the filter

[Image: envelope]

Question 8

Q: N95 respirators:
- Should be stored in dry envelopes marked with the healthcare workers name (correct)
- Should be worn by patients to reduce the TB bacilli in the environment
- Can be safely reused over and over again for up to one month
- Can still be used even if torn, as long as a fit test has been done
If chosen: Correct

How do you protect yourself from TB?

Consider TB in every patient

Triage and Isolate suspected TB patients

Educate others about cough etiquette

Communicate TB risk to others

Don't expose yourself unnecessarily

Wear protective equipment properly and consistently

[Image: tb]

Intermittent surgical mask use cuts TB risk!

Surgical face masks worn by TB patients can dramatically reduce TB transmission

Remember that hostipalised TB patients only need to wear masks when HCWs enter ther room, or when the patient needs to leave the room for examination

American Journal of Respiratory and Critical Care Medicine, vol. 185, 2012

[Image: Science!]

Question 9

Q: When should patients with infectious TB be required to wear a surgical mask?
- When patients are sent home from the hospital
- When TB patients are in a closed or poorly ventilated area with other persons (correct)
- When TB patients are in ther own single room for long periods of time
- When TB patients are allowed to go outdoors
If chosen: Correct!