Transcript Tuberculosis

Tuberculosis
What Is It?
• Bacterial infection
• Caused by Mycobacterium tuberculosis
(also called tubercle bacillus)
• Damages a persons lungs or other parts
of the body
• Fatal if not treated properly
Transmission
• Spreads through the air when a person with
active TB
–
–
–
–
–
–
Coughs
Speaks
Laughs
Sneezes
Sings
Another person breathes in the bacteria and
becomes infected
Inside the Body
• Breath in infected air and bacilli go to lungs
through bronchioles
• Bacilli infect alveoli
• Macrophages attack bacteria, but some
survive
• Infected macrophages separate and form
tubercles
• Dead cells form granulomas
Active vs. Latent Infection
• Unhealthy person
– Bacilli overwhelm immune system
– Bacilli break out of tubercles in alveoli and spread
through bloodstream
– This is ≥active≤ TB
• Healthy person
– Initial infection controlled by immune system
– Bacilli remain confined in tubercles for years
– This is ≥latent≤ TB
Symptoms
•
•
•
•
•
•
•
•
•
Perpetual Cough
Fever
Weight loss
Night sweats
Loss of appetite
Fatigue
Swollen glands
Chills
Pain while breathing
Diagnosis
• Skin test- Mantoux test
• PPD injected in forearm and examined
2-3 days later
• Red welt around injection indicates
infection
• Examine medical history, x-rays, and
sputum
Most Susceptible
• People at higher risk of TB infection
–
–
–
–
–
–
–
Close contacts with people with infectious TB
People born in areas where TB is common
People with poor access to health care
People who inject illicit drugs
People who live or work in residential facilities
Health care professionals
The elderly
Most Susceptible
• People at higher risk of active TB
disease
– People with weak immune systems
(especially those with HIV or AIDS)
– People with diabetes or silicosis
– People infected within the last 2 years
– People with chest x-rays that show
previous TB disease
– Illicit drug and alcohol abusers
Treatments
• Take antibiotics for 6-12 months
• Preventative drug to destroy dormant
bacteria
• For active TB, 4 medications: isoniazid,
rifampin, ethambutol, and pyrazinamide
• Vaccines (relatively ineffective today)
Biological Effects on Humans
• Causes more deaths than any other infectious
disease
• About 2 billion people infected worldwide
• Major health problem in developing countries
• Leading killer of youth and young adults
• Leading cause of death for women of
childbearing age