tuberculosis: key issues for ipac
TRANSCRIPT
Tuberculosis: key issues for IPAC Dr Elizabeth Rea AMOH, Toronto Public Health
June, 2018
IPAC-SWO Chapter
Objectives
No conflicts of interest to declare
Basics of TB, and infectiousness
IPAC issues in hospital and leaving
hospital
Contact investigation and occ health
follow-up
TB in Ontario, or why this is worth
paying attention to
600+ cases/yr
Most TB in GTA, but
increasingly occurring
across Ontario as
immigration widens
Immunocompromised
patients,
international students
Hospitals with 200+ beds:
high risk =
6+ TB cases per year
TB 101: a slow illness
• Slow-growing bacteria
• Serious illness – but preventable, treatable, curable
• Treatment is 6+ months of special antibiotics
• TB in the lungs is infectious
• only 10% of people who get infected will get sick… months or years later
•TB care and medication is free to patient in Ontario
TB clinical presentation
•New or worsening cough 2+ weeks
•Fever, night sweats
•Fatigue
•Anorexia
•Weight loss
•Hemoptysis
•1/3 Extra-pulmonary: varies with site
High-risk groups
High risk of exposure (infection, LTBI): born in TB-endemic country
- Refugee camps
native Canadians on / from northern reserve or Arctic
- shelter system; jail?
High risk of progression to active disease: contact of active TB in last 2 years
recent immigration (2-5 years)
immunocompromised (HIV, ca, elderly, diabetes, babies, malnutrition, alcoholic…)
- homeless
The Global TB epidemic
•¼ of all humans
infected with TB
Global TB Rates
http://www.who.int/tb/publications/global_report/en/
Diagnostic testing for TB
•CXR or CT
•Sputum x3 (or biopsy) for TB:
–AFB smear (24 hours), PCR (48 hrs) and
culture(1-4 weeks)
–Drug sensitivities – all first line (1-2 more
weeks)
TB Infection Vs. TB Disease
TB Infection (LTBI) (Not Active-Latent)
• +ve skin test
• not infectious • no symptoms • bacteria=dormant • normal CXR • medicine - optional
TB Disease (Active-replicating)
• +ve skin test
• infectious in lungs • symptomatic • bacteria=multiplying • abnormal CXR • must take medicine
TB has a lot of baggage
• many people remember when
TB was hard to cure – many have
relatives who were very ill or died
TB can be scary
• many cultures link TB and
“being dirty” or poor TB can feel
shameful, not a respectable
illness
• TB is spread through the air it
can feel like you don’t have
control
Hospital TB in the news…
Hospital TB in the news…
Pop quiz
Is this patient infectious?
Infectiousness
Only respiratory TB
contagious
TB is NOT exquisitely
infectious
Close, prolonged contact
Smear (AFB) +ve
Cavitary
Coughing
Young children rarely
infectious
IPAC and TB
72 yr old man immigrated from India 10 years ago,
4 week history of fever, cough, SOB, anorexia, 5
kg weight loss.
Clinician concerned about TB
Do not wait for lab results!
Airborne isolation
pending work-up
• Sputum smear negative (2-3 sputum samples)
• Alternate diagnosis (TB ruled out)
OR if TB diagnosed:
• Sputum smear negative (2-3 samples)
• On adequate TB meds at least 2 weeks
• Drug sensitivities known
• Clinical improvement
Criteria to d/c airborne precautions
Discharge Planning
19 year old international student from Korea with
extensive cavitary smear 4+ pulmonary TB.
Unwell, but stable on standard TB x 24 hours.
Anxious to get out of hospital – his insurance
doesn’t cover TB (“pre-existing condition”)
Can he go home?
• Clinically well enough!
• Public health notified (home environment assessed, meds, DOT)
• Follow-up plan
• If home environment safe, do NOT have to be non-infectious to d/c
• Discharge to LTC or other congregate settings: MUST be non-infectious
• If infectious: do not put on public transit to get home!
Discharging home
Ensure all TB patients get good TB care and complete treatment, minimize further transmission, make it easier to do the right thing
TB is reportable, so that:
All TB meds free through public health
Every patient with active TB has a public health nurse
Case management
discharge planning, isolation while infectious
education / support for patients, families
DOT (directly observed therapy)
Working with difficult situations, legal aspects
TB-UP (outpatient care if no OHIP)
Contact tracing
Public Health TB Care
Home isolation
• Provincial TB-UP program covers all TB diagnostics, physician billing, and TB meds for patients with no insurance and unable to pay
• Access through local public health unit
• TB diagnosis does not have to be confirmed already – will cover the work-up
• Does not cover in-patient bed fee
TB – no health insurance ?!
Contact Tracing Objectives
• Identify and screen contacts at risk of infection
• Isolate and Initiate treatment for secondary cases
• Offer preventive treatment to contacts with latent TB infection (LTBI)
• Identify and fix gaps in infection control, policy, practice
…but who to screen?
Breaking the chain
Exposure to
infectious case
Susceptible
host Infectious case
Susceptible
host
Exposure to
infectious case Infectious case
- Early detection of secondary cases
(1%)
- Detection and treatment of (new) LTBI
TB Contact Follow-up
approach
1. Risk assessment - define contacts
2. Identify specific contacts
3. Find contacts
4. Test/screen contacts Treat those who are ill or infected
5. Review results: expand contact follow-up?
6. Identify and fix gaps in infection control, policy, practice
Risk Assessment for TB
exposure
environment
Setting(s)
people
Infectiousness of index case
Duration of exposure
Hospital considerations
• Congregate setting where outbreaks can occur
• Patients at higher risk of becoming infected due to
illnesses or immunocompromising medical/surgical
interventions
• Responsibilities re staff exposures – risk to staff,
future risk to patients
• LTBI treatment often not possible for patient contacts – and very low uptake among staff contacts
• Large number of patients, staff, visitors – without a
structured systematic approach can easily become
huge, unfocused, and ineffective
Variable hospital exposure
variables!
• Wide range of ventilation 2-30 ACH
• Variable types/intensity of exposures - unique
procedure exposures, intensive personal care,
etc
• Variable baseline TB programs (IPAC and Occ
Health)
Contact investigation works best if adapted
thoughtfully to specific hospital settings, exposure
events, and information – eg measured air
exchange in TB exposure locations
Nosocomial Transmission
• no nosocomial transmission over 5 year evaluation period in
Toronto (487 patient contacts evaluated)
• since 2007, two nosocomial secondary cases among patient
contacts, both confirmed on TB strain genotyping
• Highly infectious index cases
(cavitary, smear 4+)
• Significantly immunosuppressed
roommates
• Shared 6 and 16 nights in the same
room with index
Staff exposure
• since 2007, 3 nosocomial TB transmissions to staff in
Toronto that we know of (there may be more!)
• all involved airway management of an unsuspected smear
positive pulmonary TB patient
• One documented converter became secondary case –
genotype match to index case
very few acquire TB at work, but non-zero risk!
HCWs are people too
• People with active TB in Toronto include nurses, doctors, dentists, physiotherapists…6% are HCW
•Almost all acquired TB in country of origin – like most other TB cases in Toronto
Toronto’s New and Improved Tool for Initial TB Contact Investigation (contact parameters tool v3.0)
What is the CSPT?
• Developed and evaluated in the Toronto context
• Evidence-based operational tool
• Consistent, systematic approach
• Puts parameters on hours of exposure
• Minimum guidelines for initial investigation
The Contact Screening Parameters Tool (CSPT) is an operational, risk-based approach for prioritizing contact follow-up for infectious tuberculosis cases
• Contact follow-up decision making is an iterative process
• Always consider the specific circumstances, work from first principles, and re-evaluate outcomes to adapt (as needed)
What the CSPT is NOT
CSPT is NOT a recipe book!
CSPT: An Evolution
2007 - 2016 2005 – 2007
2016 Validation study
Can we improve on the concentric circle
approach and prioritize contact follow-up better?
Is the CSPT working? Can we improve
the tool?
• 960 Pulmonary TB cases, June 2007 to May 2012
• 6,428 Contacts identified according to CSPT
• iPHIS, Contact Investigation Line Lists, Genotyping/OUT-TB through to 2014
• Literature review
06/05/2014
SITE SCREENED
Case Manager Case managers use only
Index Case Resp AMTD : Date Case Reported :
Name
Date of Birth (mm/dd/yyyy)
iPHIS ID# Revised 2011.01.041615778
Contact name, iPHIS
ID#
Relation-
ship to
Case
(coded)
DOB
mm/dd/yyyy
Eligible
for
follow-up
(coded)
Last date of
exposure
mm/dd/yyy
Risk
factorsLocated Origin
Previous
Positive
TST
Date read
mm/dd/yyyy
Result
(+ or -)
Date read
mm/dd/yyyy
Result
(+ or -)
Date
mm/dd/yyyy
Result
(coded)
Date taken
mm/dd/yyyy
Result
(coded)Started?
Complet
ed?
Sympto
matic ?Comments
IDENTIFIED CONTACTS - LINE LIST
Culture :
Sensitivities :
AFB smear :
GROUP SCREENED
Specimen type:Non-Resp
Symptom onset date:
CXR:
Total infectivity rating:
SputumCXR ProphylaxisSkin Test at < 8
Weeks
Skin Test at >8
Weeks
Click here to sort by
CSPT Evaluation
CSPT: Section 1
3
Hospital Updates
• Limited literature in hospital settings
• Community-based settings
• Four studies on specific exposure times required for transmission
• Average exposure time to a highly infectious case (cavitary, smear +) for transmission to occur = 360 cumulative hours
Close Non-Household (CNHH) Low High
Contacts >5 years 120+ hours 96+ hours
Immunosuppressed, contacts <5 years 60+ hours 36+ hours
Updated Hospital Guidelines
Low High
Patients with ≥48 hours cumulative exposure in the same room, or for larger bay areas the patients in adjacent beds, or participation in patient group activities (e.g. pediatric play room, psychiatric group programs) – TST > 8 weeks BIC, unless <5 years old, initial & repeat TST Staff with direct patient care for ≥60 hours cumulative exposure; all staff involved during cough inducing/aerosolizing procedures if not wearing PPE – TST > 8 weeks BIC
Patients with ≥ 24 hours cumulative exposure in the same room, or participation in patient group activities (e.g. pediatric play room, psychiatric group programs) – TST > 8 weeks BIC, unless <5 years old, initial & repeat TST Staff with direct patient care ≥ 36 hours cumulative exposure; all staff involved during cough inducing/aerosolizing procedures if not wearing PPE – TST > 8 weeks BIC
Immunosuppressed contacts: Examples of immunosuppressed contacts include HIV positive with low CD4 counts; dialysis, oncology, and transplant patients. Consider lowering threshold based on extent of immunosuppression and closeness of exposure (e.g. direct caregivers). Consider symptom assessment and chest x-ray with or without TST, and flag TB exposure in the client's hospital/physician chart.
CSPT: Section 3
Emergency Medical Services
• notify to keep in the loop, along with any follow-up recommendation
Public travel (new!)
• no follow-up for local transit
• only consider for long distance travel if evidence of transmission among closer contacts; for air travel, continue to use PHAC guidelines
Wound care (new!)
• only follow-up staff who were involved in high pressure irrigation of open TB wounds that are smear AND culture positive AND were not wearing an N95 mask
Adapting the parameters
• Assess size of room and ventilation: if tiny and stuffy, lower hours of exposure threshold (and the opposite!)
• Beware of lunchrooms and outdoor smoking sites
• Babies and toddlers: lower hours of exposure based on closeness/care-giving
• 120 hours is not magically different from 116 hours – use judgement and consider operational factors
• For individual contacts, add up their exposure in multiple settings
• Always evaluate contact investigation outcomes for each case – expand contact follow-up? Using what new parameters?
Follow-up processes – ideally…
• Public Health, IPAC and OccHealth
collaborate to identify patient, visitor, staff
contacts meeting applied CSPT criteria
• Meetings to coordinate complex follow-up
(e.g. NICU, hemodialysis, oncology)
• Community and hospital contact results
pooled to decide if expansion needed
Occ Health TB programs
Baseline TST
Annual repeat TST for high
risk settings (ER, general
medicine, lab, etc)
Contact follow-up for specific
TB exposures
Occ Health: TB prevention
Every hospital screens staff for TB
Every positive TST screen is a chance to
discuss LTBI treatment…and prevent HCW
TB
On-line TST interpreter: http://tstin3d.com/
Using it outside Toronto
• CSPT was developed and evaluated based on use in the Toronto context – urban, high proportion of foreign-born with high baseline TST positivity, Toronto built environment
• Hospital recommendations will work best in context of a good occ health TB program and measured air exchange rates
• Want a copy of the tool and documentation?
416-338-7600
Questions?
Questions?
Dr Elizabeth Rea Toronto Public Health TB Program
416-525-3794 416-338-7600
Type of Follow-up
• TB symptom assessment should be done for EVERYONE and if anyone is symptomatic, collect sputum.
• For most settings (household, CNHH, schools and daycares and shelters) initial & repeat TST
• In most other settings, or if the first opportunity for testing is close to the 8 week mark – post 8 week TST is sufficient
• Elderly clients, immunosuppressed and LTCF – include symptom assessment and chest x-ray and flag the patient’s file; only do a TST if LTBI treatment is an option
• Children <5 years should always have an initial and repeat TST with medical assessment and window prophylaxis, in any setting