Tuberculosis Flashcards
Etiopathogenesis of TB
- caused by Mycobacterium Tuberculosis
- Transmission: droplet nuclei
- 85% lungs
- Most infectious patients: cavitary pulmonary disease
- Typical TB lesion
- epitheloid granuloma with central caseation necrosis
Presumptive TB
- Any person who presents with sx or signs (>15 years old)
- Cough >2 weeks
- Unexplained cough of any duration in those with close contact with a known active TB case, high risk group
- Associated sx: weight loss, fever, hemoptysis, chest/back pain, fatigue, night swets, dyspnea
- CXR findings suggetive of TB
- Presumptive EPTB; may have gibbus, neck stiffness, lymphadenopathy, pleural or pericardial effusion, ascites, painful joints, tuberculin hypersensitivity
TB EXPOSURE
Individual is in close contact with an active adult TB case, but without signs and symptoms of TB;
- with negative TST reaction, and
- no radiologic or laboratory findings suggestive of TB
TB infection or Latent TB infection
- Individuals have no signs, symptoms, Radiologic nor laboratory evidence of TB, but has a positive TST reaction
- Treatment is not recommended
TB Disease
Individual with presumptive TB who is confirmed to have TB by any clinical and diagnostic evaluation
Classification of TB-Disease based on Anatomical Site and bacteriologic Status
Classification Based on History of Previous Treatment
-
New case
- Never had treatment or who has taken anti-TB meds <1 month
-
Retreatment case
- previously treated for at least 1 month
-
Relapse
- previously treated, was declared cured or completed the treatment, and is now bacteriologically or clinically diagnosed TB
-
Treatment After Failure
- Previously treated and failed treatment
- Sputum smear or culture (+) at 5 months or later during treatment
- Clinically diagnosed patient, no sputum, without clinical improvement anytime during the course
- Previously treated and failed treatment
-
Treatment after Lost to follow-up
- Previously treated but Lost to follow up for >2 months and currently diagnosed TB
-
Previous Treatment Outcome Unknown
- Previously treated
- Outcome not documented
algorithm for DX of TB
Management of TB
Classification based on Drug Susceptibility
-
Monoresistant TB
- only to 1 first line drug
-
Polydrug resistant
- >1 first line (other than both INH and Rifampicin)
-
MDR-TB
- both INH and Rifampicin
-
XDR-TB
- any fluoroquinolone and to at least 3 2nd lne injectable drug (capreomycin, Kanamycin, Amikacin) in addition to MDR
-
RR-TB
- Rifampicin detected using phenotypic or genotypic methods with or without Resistance to other
- Rifampicin, whether monoresistance, MDR, PDR, or XDR
Category I
New PTB
New EPTB
-
Initial Phase
- 2 HRZE
-
Continuation
- 4HR
Category Ia
New EPTB (CBS/bones or joints)
-
Initial phase:
- 2HRZE
-
Continuation Phase:
- 10 HR
Category II
Previously Treated PTB or EPTB (escept CNS, bones or joint)
- Relapse
- Treatment after Failure
- TALF
- Previous Treatment Outcome Unknown PTOU
- Other
-
Initial Phase
- 2 HRZES and 1 HRZE
-
Contunuation Phase
- 5 HRE
Category IIa
Previously treated drug-suceptible EPTB in CNS/bones orjoints
-
Initial Phase
- 2 HRZES and 1 HRZE
-
Continuation
- 9HRE
Drug resistant TB
Standard regimen Drug Resitant: RR-TB or MDR-TB
XDR TB Regimen
Isoniazid
- inhibits fatty acid synthase and mycolic acid synthesis
- Excellent bactericidal activity against both intracellualr and extracellualr actively dividing MTB
- Bacteriostatic against slowly dividing mciroorganisms
5mg/kg
Max: 400 mg
Rifampicin
- Binds to and inhibits mycobacterial DNA-dependent RNA polymerase thereby blocking RNA synthesis
- Has both intracellular and extracellular bactericidal activity, both in dividing and non-dividing MTB
- Has sterilizing activity
- Most Active antimycobacterial agent available and therefroe the keystone of 1st line TB
10mg/kg
max 600 mg
Minor SIde effects of Drugs
(may continue anti-TB drugs and check doses)
Monitoring Response to Treatment using follow-up DSSM
Pyrazinamide
- Exact mechanism is unclear (fatty acid synthetase-I may be the primary target)
- More active against slowly replicating organisms than against actively repliating organisms
- Active only in acidic environment (ph<6.0) as are fouund within phagocytes or granulomas
25 mg/kg
max: 2 g
Ethambutol
- Inhibits arabinosyltrasnferases involved in cell wall synthesis, which probably inhibits the formation of arabinogalactan and lipoarabinomannan
- Bacteriostatic antimycobacterial agent which provides synergy with other drugs
- Least potent against MTB
15 mg/kg
Streptomycin
- Inhibits protein synthesis by binding at a site on the 30s mycobacterial ribosome
- Bactericidal against dividing MTB but has only low level early bactericidal activity
15g/kg
max 1 g
Bacteriologically-confirem TB patient (sputum-positve at the beginning of treatment) and smear is smear (-) or culture (-) at the last month of treatment and on at least 1 previous occasion in the continuation phase
CURE
A patient completes treatment, but does not meet the criteria of “cured: or failure”
- Bacteriologically confirmed patient who has completed treatment but without DSSM follow-up in the last month of treatment and on at least 1 previous occasion
- Clinically diagnosed patient who has completed treatment
Treatment completed
- For bacteriologically-confirmed TB: patient who is sputum smear positive at 5 months or later during the treatment, or
- For clinically diagnosed TB: patient for whome sputum examination cannot be done and who does not show clinical improvement during treatment
Treatment Failed
Sum of “cured: and “treatment completed”
Treatment success
PAtient whose treatment was interrupted for >=2 consecutive months
Lost-to follow up
- A patient for whom no treatment outcome s assigned
- Includes patients transferred to another treatment facility with outcome unknown
Not evaluated
