Infectious TB Flashcards
Most common and important myco
M tuberculosis
TB transmission
droplet nuclei
Higher probability of infection in
intimacy and duration of contact
degree of infectiousness of case
shared environment of contact
Most likely to transmit infection
Smear +
Cavitary disease
Laryngeal TB
Non infectious TB
Culture negative
Extra pulmonary TB
Clinical illness directly follows infection
Children and first few years of life
Severe
Non high transmissibility
Primary TB
Reactivation after bacteria has persisted for years
More infectious because of cavitation
Secondary TB
LN Pleura Genitourinary tract Bones and joint Meninges Peritoneum Pericardium
Extrapulmo TB
Tb pathogenesis
Microorganism inhaled by close bystander Majority trapped in upper airway <10% reach alveoli Phagocytosis by resident mac Initiated T cell dysregulated response
A patient who presents with symptoms and signs of TB (radio finding) even without active sx
Presumptive TB
A patient from whom a biological specimen is positive by smear microscopy culture of GeneXpert
Bacteriologically confirmed case
Patient who does not fulfill criteria of bacteriologically confirmed TB
Dx if started on treatment
Clinically diagnosed TB
Cough at least 2 w duration
Unexplained cough of any duration with close contact of known TB case
Chest Xray findings suggesive of TB with or without symptom
Presumptive TB
Presumptive TB sc
cough any duration Weight loss Fever Hemoptysis Chest pain not musculo Body malaise Easy fatigability Night sweat Shortness of breath
Proper way of collecting sputum
Spontaneous expectoration
2 sputum specimen at least 1 tsp 5-10ml in quanitity
Same day spot-spot strategy using 2 consec specimens collected 1 hr apart for Zirl Neelsen
Preferred type of microscope
LED
more sensitive and specific
DSSM +
if at least 1 sputum positive
GeneXpert requested if
Initial diagnostic in adult with presumptive TB
As follow on test to smear negative px but with chest xray finding suggestive
An initial dx test for presumptive drug resistant case
Gold standard for dx
TB culture
Culture if
Retreatment
Treatment failure
Known drug resistant
Patient never been treated for TB or has taken anti TB drug for less than 1 month
New case
Prophylactic tx
Isoniazid
Previously treated, declared cured or tx complete at end of most recent course but now dx with recurrent episode of TB
Relapse
Previously tx but declared failed to tx
Treatment failure
