Tuberculosis Flashcards
Caused by bacteria of the Mycobacterium tuberculosis complex
Tuberculosis
The most potent risk factor for TB among infected individuals
HIV co-infection
Most commonly involved in primary TB
MIDDLE AND LOWER LUNG ZONES
Lesion forming after initial infection; usually peripheral and accompanied by transient hilar or paratracheal lymphadenopathy
Ghon focus
Ghon focus, with or without overlying pleural reaction, thickening, and regional lymphadenopathy
Ghon complex
TB in young children - almost invariably accompanied by
HILAR OR PARATRACHEAL LYMPHADENOPATHY due to the spread of bacilli from the lung parenchyma through lymphatic vessels
Reactivation or secondary TB
Postprimary (Adult-Type) Disease
Postprimary (Adult-Type) Disease is usually localized to the
apical and posterior segments of the upper lobes
substantially higher mean oxygen tension (compared with that in the lower zones) favors mycobacterial growth
Produced d.t. massive involvement of pulmonary segments or lobes with coalescence of lesions
caseating pneumonia
HEMATOLOGIC FINDINGS: Postprimary (Adult-Type) Disease
mild anemia
leukocytosis
thrombocytosis with a slightly elevated erythrocyte
sedimentation rate and/or C-reactive protein level
MC presentation of extrapulmonary TB in both HIV-seronegative and HIV-infected patients
Lymph Node TB (Tuberculous Lymphadenitis)
presents as painless swelling of the lymph nodes
at posterior cervical and supraclavicular sites (scrofula –past name)
Reflects recent primary infection
pleural TB
Results from the hematogenous spread of primary or postprimary pulmonary TB or from the rupture of a subependymal tubercle into the SUBARACHNOID SPACE
tuberculous meningitis
Miliary or Disseminated TB
• due to hematogenous spread of tubercle bacilli
• CHILDREN: consequence of primary infection
• ADULT: recent infection or reactivation of old disseminated foci
Pathognomonic of miliary TB
choroidal tubercles (eye)
A presumptive TB case that is either bacteriologically confirmed or clinically diagnosed by the attending physician
Active TB
Refers to a case of tuberculosis involving the LUNG parenchyma.
Pulmonary TB
A patient with both pulmonary and extrapulmonary tuberculosis should be classified as a
case of pulmonary TB.
Refers to a case of tuberculosis involving organs other than the lungs (e.g. larynx, pleura, lymph nodes, abdomen, genito-urinary tract, skin, joints and
bones, meninges)
Extrapulmonary TB
Refers to a patient from whom a biological specimen,
either sputum or non-sputum sample, is positive for TB by smear microscopy, culture or rapid diagnostic tests (such as Xpert MTB/RIF, line probe assay for TB, TB LAMP).
Bacteriologically confirmed TB (BCTB)
Refers to a patient for which the criterion for bacteriological confirmation is not fulfilled but diagnosis is made by the attending physicians on the basis of clinical findings, X-ray abnormalities, suggestive histology and/or other biochemistry or
imaging tests
Clinically diagnosed TB (CDTB)
Refers to a patient who has never had treatment for TB or who has taken anti-TB drugs
for less than one month.
Preventive treatment is not considered as previous TB treatment
New Case
Refers to a patient who had received one month or more of antiTB drugs in the past
Also referred to as Retreatment.
Previously Treated for TB
Previously treated for TB, new TB cases that are contacts of confirmed DR-TB cases or non-converter among patients on DS-TB regimens
High risk for multidrug-resistant tuberculosis (MDR-TB)
Resistance to rifampicin detected using phenotypic
or genotypic methods, with or without resistance to other anti-TB drugs
It includes any resistance to rifampicin, whether monoresistance, multidrug resistance, polydrug resistance or extensive drug resistance
Rifampicin-resistant TB (RR-TB)
The time from collection of first sputum sample to initiation of treatment for TB
Turnaround time (TAT)
The desired turnaround time is five working days (also referred to as Program TAT).
Previously treated for TB and declared cured or treatment completed, but is presently diagnosed with active TB disease
Relapse
Previously treated for TB but failed most recent course
based on a positive SM follow-up at five months or later, or a clinically diagnosed TB patient who does not show clinical improvement anytime during treatment
Treatment after Failure
Previously treated for TB but did not complete
treatment and lost to follow-up for at least two months in the most recent course
Treatment after lost to follow up
Previously treated for TB but whose outcome in the most recent course is unknown
Previous treatment outcome unknown
Patients who do not fit any of the categories listed above or previous treatment history is unknown (this
group will be considered as previously treated also)
Patients with unknown previous TB treatment history
PTB or EPTB (except central nervous system [CNS], bones, joints) whether new or retreatment, with final Xpert result:
MTB, RIF sensitive
MTB, RIF indeterminate
New PTB or new EPTB (except CNS, bones, joints), with positive SM/TB LAMP or
clinically diagnosed, and:
Xpert not done*
Xpert result is MTB not detected
2HRZE/4HR
EPTB of CNS, bones, joints whether new or retreatment, with final Xpert result:
MTB, RIF sensitive
MTB, RIF indeterminate
New EPTB of CNS, bones, joints, with positive SM/TB LAMP or clinically diagnosed, and:
Xpert not done*
Xpert result is MTB not detected
2HRZE/10HR
Side effects of Isoniazid
Burning sensation in the feet due to PERIPHERAL NEUROPATHY
-Give PYRIDOXINE (Vit B6) 50–100 mg daily for
treatment; it can also be given 10 mg daily for prevention
Psychosis and convulsion
Side effects of Isoniazid
MINOR
Burning sensation in the feet due to PERIPHERAL NEUROPATHY
-Give PYRIDOXINE (Vit B6) 50–100 mg daily for
treatment; it can also be given 10 mg daily for prevention
Gastrointestinal intolerance - give drugs at bedtime or with small meals
MAJOR
Jaundice due to hepatitis
Psychosis and convulsion
Side effects of Rifampicin
MINOR
Gastrointestinal intolerance - give drugs at bedtime or with small meals
Orange-colored urine - reassure the patient
Flu-like symptoms (fever, muscle pains, inflammation of the respiratory tract) - pyretics
MAJOR
Oliguria or albuminuria due to renal disorder
Jaundice due to hepatitis
Thrombocytopenia, anemia, shock
Side effects of Pyrazinamide
MINOR
Gastrointestinal intolerance - give drugs at bedtime or with small meals
Jaundice due to hepatitis
Arthralgia due to hyperuricemia
Ethambutol
Impairment of visual acuity and color vision due to optic neuritis
A patient with bacteriologically confirmed TB at the beginning of treatment and who was smear- or culture-negative in the last month of treatment and on at least one previous occasion in the continuation phase.
Cured
A patient who completes treatment without evidence of failure but with no sputum smear negative results in the last month of treatment and on at least one previous occasion, either because tests were not done or because results are unavailable.
This group includes clinically diagnosed patients who completed treatment.
Treatment Completed
A patient whose sputum smear or culture is positive at five months or later during
treatment.
Treatment terminated because of evidence of additional acquired resistance (e.g. RIF resistance on Xpert at 2nd month)
A patient for whom follow-up sputum examination was not done (e.g. child or EPTB) and who does not show clinical improvement anytime during treatment.
Severe uncontrolled adverse drug reaction
Treatment Failed
A patient who dies for any reason during the course of treatment.
Died
A patient whose treatment was interrupted for at least two consecutive months.
A patient diagnosed with active TB but was not started on treatment (i.e., initial LTFU).
Lost to follow-up (LTFU)
A patient for whom no treatment outcome is assigned.
This includes patients transferred to another facility for continuation of treatment but the final outcome was not determined.
Not Evaluated
Isoniazid
5 mg/kg, max 400 mg
(-) FAS and mycolic acid synthesis
excellent BACTERICIDAL
BACTERIOSTATIC against slowly dividing organisms
Rifampicin
10 mg/kg, max 600 mg
binds to and (-) mycobacterial DNA dependent RNA polymerase –> blocking RNA synthesis
both intracellular and extracellular BACTERICIDAL
w/ STERILIZING activity
MOST ACTIVE antimycobacterial agent available
KEYSTONE of the 1st LINE TB TREATMENT
Pyrazinamide 25 mg/kg, max 2 g
Fatty acid synthetase I
more active against SLOWLY replicating organisms
active only in ACIDIC environment
Ethambutol 15 mg/kg
(-) arabinosyltransferases involved in cell wall synthesis
BACTERIOSTATIC
LEAST POTENT
