T.B Guidelines- Dr Armando

Question 1

What is mono-resistant T.B?

Answer 1

-Resistant to a single first line anti-TB drug

Question 2

What is poly-resistant TB?

Answer 2

-Resistant to more than one first line anti T.B drugs
eg Rifampicin and Pyrazinamide
or Rifampicin and Ethambutol

Question 3

What is MDR-TB?

Answer 3

-Resistant to H (Isoniazid) AND R(Rifampicin) with or without resistance to other anti-TB drugs.

Question 4

What is XDR-TB?

Answer 4

-MDR-TB plus resistance to any of the fluoroquinolones plus one or more of the injectable second line ant-TB drugs eg K (Kanamycin),
Am(Amikacin ) or Cm (Capreomycin)

Question 5

What are the questions to ask to screen for T.B and when to investigate?

Answer 5

1. Current Cough of any duration?
2. Persistent fever of more than 2 weeks?
3. Unexplained weight loss of more than 1,5 kg in a month?
4. Drenching night sweats?

All pts with one or more of these sx must be further investigated for active T.B

Question 6

What are the different lab test you can request?

Answer 6

1. AFB Sputum (smear microscopy for TB):
   - With this test you can not be 100% sure that it is Mycobacterium T.B, it can be any other mycobacterium.
   - However because in SA mycobacterium T.B is the commonest you can assume its more likely mycobacterium T.B.

Question 7

Lab test 2?

Answer 7

2. Line Probe Assay (LPA)
   - This test detects the gene specific for mTB, so you can be sure it is mTB.
   - Also able to detect mutations, therefore can show if there is resistance to Rifampicin and Isoniazid (H)
   - You can even request LPA for second line drugs

-However not available everywhere.

Question 8

Lab test 3?

Answer 8

3. GeneXpert MTB/ RIF
   - You can be sure its mTB
   - Confirms resistance to Rifampicin only.

-Always important to send a good quality sample, otherwise T.B can be missed.

Question 9

Lab test 4?

Answer 9

4. T.B Culture, Identification of species and DST
   - also a drug sensitivity test
   - Takes very long eg 4-8 weeks to get the results.

Question 10

GeneXpert Results:

Answer 10

1. GXP Negative= No T.B
2. GXP Unsuccessful.

3.GXP Positive
-with Rifampicin Susceptible
or
-with Rifampicin Resistant
or
-with Rifampicin Unsuccessful

Question 11

What do you do when GXP is positive with R susceptible?

Answer 11

1. Treat as T.B
   - Start on regimen 1
   - Send one specimen for microscopy

-F/up with microscopy

Question 12

What to do when GXP is positive with Rifampicin Resistant?

Answer 12

1. Treat as MDR-TB
   - Refer to MDR-TB unit
   - Collect one specimen for *microscopy *culture and DST for Rifampicin, Isoniazid, Fluoroquinolone and Aminoglycoside.

-F/up with microscopy and culture

Question 13

What to do for GXP positive with Rifampicin Unsuccessful?

Answer 13

1. Treat as T.B
   - Start on Regimen 1.
   - Collect one specimen for microscopy culture and DST/LPA

Question 14

What to do when Genexpert is Negative?

Answer 14

-It depends if the pt is HIV positive or negative

Question 15

What to do when GXP is Negtaive and pt is HIV Negative?

Answer 15

1. Treat with Antibiotics
   - Which one?

2.If there is good response, then no further f/up, advise to return if sx recur.

If poor response then consider other dx and refer for further investigation.
(Maybe the sputum sample was not that great)

Question 16

What to do if GXP is negative and pt is HIV Positive?

Answer 16

1.Collect one specimen for culture and LPA or
Culture and DST (For R and H)

2.Treat with Abx and review in 5 days
Which Abx?

3.Do a chest Xray

Review after 5 days:

*If poor response to Abx then clinicaly it is TB.
Chest Xray might also show T.B.
Mx: Treat as T.B, start regimen 1
-Review culture results.

When reviewing LPA/DST results and it shows resistant to R and H/R only then treat as MDR TB and refer to MDR TB unit.

Question 17

What to do if GXP is unsuccessful?

Answer 17

1.Collect one sputum specimen for a repeat GXP.

Question 18

What is the regimen 1 for starting pts on anti-TB tx?

Answer 18

This regimen is for adults and children older than 8 years who weigh more than 30 kg:
Tx dependent on weight of pts.

Tx divided into 1.Intensive phase for 2 months.
2.Continuation phase for 4 months.

1. Intensive Phase
Drugs = RHZE (150,75,400,275)
*30-37 Kg =2 tab
*38-54 kg =3 tab
*55-70 kg= 4 tab
*More than 70 kg= 5 tab

2.Continuation Phase
Drugs= RH (150,75) or RH (300,150)

• 30-37 Kg= 2 tab of RH (150,75)
• 38-54 Kg= 3 tab of RH (150,75)
• 55-70 kg= 2 tab of RH (300,150)
• More than 70 Kg= 2 tab of RH (300,150)