Goal
To discuss and refine current definitions of cases and
treatment outcomes for non MDR-TB and MDR-TB,
especially in anticipation of widespread use of Xpert MTB/RIF
Objectives
1. To review and propose refinements to current case
definitions for non MDR-TB and MDR-TB
2. To review and propose refinements to current definitions of
treatment outcomes for non MDR-TB and MDR-TB
Expected Outcomes
Agreement on a proposed set of case and treatment outcome
definitions, and steps required to adopt these definitions, for
consideration by WHO's Strategic and Technical Advisory
Group for TB (STAG-TB) in June 2011
Topics covered in discussions
1. Current case definitions and two options for
revised case definitions
2. Disaggregations for reporting of cases i.e. for
TB surveillance

keep as simple as possible, make sure there is a
good reason for collecting the data
3. Treatment outcome categories for non-MDR
TB, and definitions for each outcome
4. Treatment outcome categories for MDR-TB,
and definitions for each outcome
Case Definitions
Current Case Definitions
Definite TB case
A patient with Mtb complex
identified from a clinical
specimen, either by culture or
by a newer method such as
molecular line probe assay
+
in countries that lack the
laboratory capacity to routinely
identify Mtb, a pulmonary case
with ≥1 initial sputum smear
examinations AFB-positive, IF
there is a functional EQA
system with blind rechecking
TB case
Definite cases +
Patients that a health worker
(clinician or other medical
practitioner) has diagnosed
with TB and has decided to
treat with a full course of TB
treatment
MDR-TB case
TB caused by Mtb resistant in
vitro to isoniazid and
rifampicin, with or without
resistance to other drugs
Current Case Definitions disaggregations
Cases are classified according to:
anatomical site of disease
 bacteriological results (including drug resistance)
 history of previous treatment
 HIV status

Source: 2009 WHO treatment guidelines
These and further disaggregations are requested on WHO R&R forms
and in global data collection form
Proposed case definitions
Confirmed TB
Not confirmed TB
C+, WRD+ or Sm+ TB, for
pulmonary and EPTB
Confirmed,
probable, possible
(option 2) ruled out
TB case put on full course of
TB treatment who is not C+, WRD+ or sm+
Confirmed MDR-TB
TB case with Mtb resistant in vitro to H
and R, with/wo resistance to other drugs
Probable MDR-TB
TB case whose treatment was changed
following interruption or failure and who
is WRD+ for R resistance
Proposed disaggregations (1)
1) New 2) recurrent 3) treatment change
Confirmed TB
MDR-TB status among above 3 case types
Probable MDR-TB among treatment change
Not confirmed TB
1) New + recurrent 2) treatment change
??? Pulmonary/EP disaggregation
Confirmed MDR-TB
HIV and XDR status
17 subcategories for new + recurrent
confirmed + not confirmed cases
Proposed disaggregations for
new + recurrent (incident) TB cases
Confirmed TB,
new + recurrent
+
HIV status (tested, HIV+, on ART)
12 age and sex categories
0-4, 5-14,15-24, 25-44, 45-64, 65+
Not confirmed TB,
new + recurrent
15 subcategories for new + recurrent
confirmed + not confirmed cases
Total of 17+15 = 32 subcategories for routine surveillance,
less than the current 36 in paper-based quarterly report form
Treatment outcome
categories and definitions
Treatment outcomes –
which categories of case? – Option 1
Non-MDR-TB
MDR-TB
1.
New (confirmed + not
confirmed)
1.
First outcome of
treatment
2.
Recurrent + treatment
change (confirmed +
not confirmed)
2.
XDR and HIV+ among
MDR in countries with
ERR
3.
New and recurrent
HIV+ (confirmed + not
confirmed)
Question: disaggregate all
outcome categories by sex in
countries with ERR?
Treatment outcomes –
which categories of case? – Option 2
Non-MDR-TB
MDR-TB
1.
New (confirmed)
1.
First outcome of
treatment
2.
Recurrent + treatment
change (confirmed)
2.
XDR and HIV+ among
MDR in countries with
ERR
3.
New + recurrent +
treatment change (not
confirmed)
4.
New and recurrent
HIV+ (confirmed)
Treatment outcome categories
• Non MDR
No transfer out,
interrupted replaces default
– Cure, completed treatment, failed, died,
interrupted, not evaluated (national level)
– Report cure and completed as collapsed
category for global level, using terminology of
treatment success
• MDR (outcome of first treatment)
– Cure, failed, died, interrupted, not evaluated
MDR-TB treatment outcome definitions
(first outcome of treatment)
• Success
– Completed prescribed treatment course
– Sputum or culture conversion
– Remains negative
• Failure
Existing
definitions do
not work for
surveillance
purposes
– Need for permanent treatment change (of 2 classes of
drugs) or termination of treatment because
• lack of sputum or culture conversion, or
• reversion to positive with or without clinical deterioration
• adverse effects
• Interrupted: > 2mo
• Died
• Not evaluated
Next steps
1.
Update discussion document (keep background, then insert
case definitions and treatment outcomes agreed in this
meeting with questions requiring further discussion
highlighted (end May)




Consider frequency/timing of reporting
Where does histology+ fit
Improve wording for MDR treatment outcomes (p15 discussion doc)
Check what is/is not captured vis à vis global report
2.
Send feedback on MDR-TB treatment outcome definitions to
MDR-TB WG for consideration (existing don't work for
surveillance, but proposal from this group needs to be
discussed by MDR-TB group that developed recent guidelines)
(end May)
3.
Present to STAG for feedback (June)
4.
Consultation with multiple countries and other stakeholders
(by October)
5.
Pilot in sites rolling out Xpert (end 2011)