Bacteria III Gram (+)

Question 1

Tuberculosis Transmission

Answer 1

Respiratory droplets
Lives, reproduces inside unactivated macrophages
Carriers may appear outwardly healthy

Age of transmission varies globally:

• U.S.: adulthood
• World: infancy

Question 2

TB Disease Stages: Symptoms

Answer 2

Primary
	Asymptomatic OR flu-like
Latent
	Asymptomatic
Secondary (Reactivated)
	Rough, persistent cough
	Chest pains
	Bloody phlegm, sputum
	Highly contagious
Extrapulmonary (Disseminated)
	Goes systemic
	Granulomas (miliary TB)
	Affected areas weaken and fail
	Eventual death

Question 3

TB Disease Stages: What the Immune System is Doing

Answer 3

Primary
	Abs, T-cells not very effective
	Macrophages:
		Activated
		Try to contain it
Latent
	Tubercle formation
	Caseous necrosis
	Stalemate:
		Success: Ghon complexes (calcified tubercles)
		Failure: jailbreak
Secondary (Reactivated)
	Macrophages lose control
Extrapulmonary (Disseminated)
	Immune system can’t deal

Question 4

Jailbreak: Possible Causes

Answer 4

Immunosenescence
Anything that alters the immune system
Medications
Physical Injury 
Other diseases (infectious or non-infectious)

Question 5

Tuberculosis Treatment

Answer 5

Lots of rest
Antimicrobials:
-Rifater
-Sirturo:
--For Drug Resistance (DR) or advanced stage TB
--Risk of adverse events (heart)
Taken 1-2 years
Many and varied side effects!

Question 6

Historical Importance of Leprosy

Answer 6

Historically prevalent (Biblical tzaraath [“dreaded skin disease”])

Socially stigmatizing:
Wear bell
Social banishment
Imprisonment

Question 7

Leprosy (Hansen’s disease)

Answer 7

Two forms (but always intermediary cases):
Lepromatous
Tuberculoid (has nothing to due with TB)

Pain perception altered

Lesions more common on extremities

Question 8

What determines which form of leprosy you’ll get?

Answer 8

YOU DO!

Naïve CD4 T-cell

Proliferating T-cell

Immature T-cell (Th0)

Either:
Th1 cell (strong macrophage response)
or
Th2 cell (strong B-cell response)

Question 9

Two Leprosy Responses

Answer 9

Th1:

• Infected macrophages are activated
• Internal M. leprae are killed
• Tissue damage is local

Th2:
Antibodies produced…
…but M. leprae is inside macrophages, so antibodies can’t get to them

Question 10

Symptoms: Tuberculoid

Answer 10

Severity: Superficial ("Mild")
Infectivity: Low
Bacterial Load: often undetectable
Skin: local granulomas
Nerve Damage: Peripheral 
Ig levels: normal 
T-cell Responsiveness: Normal

Question 11

Symptoms: Lepromatous

Answer 11

Severity; Systemic ("great")
Infectivity: High
Bacterial: High, Esp, in macrophages
Skin: Disseminated Lepromas
Nerve Damage: Everywhere; disfigurement 
Ig Level: High
T-Cell Responsiveness: Stupor

Question 12

Leprosy Treatment

Answer 12

(Multiple) antibiotic resistance

Multidrug cocktail (minimum 12 months):

Surgery (severe forms)

Question 13

Leprosy Prevention & Control

Answer 13

Education

Treatment centers for those afflicted

Vaccines:

• BCG vaccine:
• -Doubles as a leprosy vaccine
• -Efficacy is dubious
• In development:
• -Live attenuated vaccine in early clinical trials
• -Sponsored by WHO