TB Flashcards
What bacterium causes TB?
Myobacterium tuberculosis
How does TB infect people?
Droplet infection – tiny droplets containing bacteria are inhaled into the lungs
What other factors affect TB?
- Poor diet
- Poor health
- Overcrowded living conditions
What are the 3 phases of TB?
- Primary infection
- Latent TB
- Active TB
Explain primary infection of TB - 7
- Bacteria cause inflammatory response from immune system
- Macrophages engulf bacteria
- Bacteria survive and replicate inside the macrophages
- Bacteria sealed off inside infected macrophages
- In anaerobic tissue masses called tubercules
- Bacteria lie dormant
- Person has latent TB and no obvious symptoms
Explain active TB - 4
- If immune system is suppressed e.g by HIV
- Dormant bacteria reactivated and overcome immune system
- In the lungs the bacteria multiply and rapidly destroy lung tissue
- Creates cavities and holes in the lungs
How long can the length of time between active TB and infection be?
Weeks/years
List the symptoms of TB - 7
- Lack of appetite leading to weight loss
- Fever
- Night sweats
- Severe coughing leading to inflammation of lungs
- Respiratory failure and eventually death
- Extreme fatigue
- Shortness of breath
How does TB affect the body other than lungs?
Can infect: brain, kidneys, glands
Describe a test for TB
- Small amount of tuberculin injected under forearm skin
- Positive result - inflamed area under injection site
What causes the inflamed reaction in the test for TB?
Antibodies, indicating TB antigens are already present
Give 2 other tests for TB
- Chest X-rays
- Identification of bacteria
How can TB be treated? 3
- Combination of 4 antibiotic drugs
- All given for 2 months
- 2 continued for a further 2 months