1. Immunity

2. What causes illness?
Most illnesses are caused by one of three types of germs (antigens):
Bacteria
Viruses
Fungi

3. Bacteria Streptococcus causes sore throats
Tetanus (muscles become locked in place (also called lockjaw)
Tuberculosis
Leprosy
Syphilis
Salmonella
Anthrax
Cholera
All of these can be treated with antibiotics

4. Cholera This is a third world disease caused by drinking dirty water
It reacts with the small intestine and causes massive diarrhoea
It can be fatal if not treated
Without fluids somebody could die within 18 hours
The fluids are usually intra venous

5. Viruses
Antibiotics do not work on viruses (it is a bad idea to take too many as your body builds up a resistance to them).
You need to be vaccinated against viruses
Viruses include:
The common cold and flu
Chickenpox
Cold sores
Ebola
AIDS

6. Smallpox
This is very important in the history of medicine as Edward Jenner developed the first vaccine for this disease
The virus loves blood capillaries and from there will cause skin rashes, then blisters
It killed million in the C20th
Due to vaccination it was eliminated by 1979
It was caught through spit, sneezing or touch
Currently there are two places where smallpox can be found one in a lab in USA and one in Russia (these are kept for future vaccines)

7. Pandemics
The Spanish Flu started in March 1918 and lasted to June 1920
This mutant flu virus killed young healthy adults (rather than children and the elderly)
Current upper estimates of the mortality rate are around 100 million (5 times more than all the deaths from the Great War(WW1)
This was 5% of the population
20% suffered from Spanish flu
25 million died in the first 25 weeks

8. The Aztecs and Incas
When the Spanish (Hernan Cortez) landed in Mexico in 1518 the population was 20 million
By 1568 this had fell to 3 million (destroying the Aztecs)
This was due to the introduction of smallpox, measles and typhus
In 1532 General Pizarro kidnapped Atahualpa the Inca leader in Peru
They had 168 men against 80,000 Incas
The Inca culture was wiped out by 1572

9. The Black Death
It is caused by bacteria commonly called the Bubonic Plague
The Black Death killed 75 million in total across Europe between 1347 and 1353
The disease lasted between the 1300s up to the C18th
The Great Plague of London was between 1665 to 1666
This is where the rhyme ring a ring of roses comes from

10. Ebola Also called haemorrhagic fever It is highly contagious
It kills 50 to 89% of the people who contract it
It can be caught through contact with bodily fluids or by touching objects used by the patient
The worst symptoms include vomiting blood, bloody faeces and blood coming out of the nose, mouth and red eyes
Death comes from multiple organ failure

11. Fungi Athletes foot is caused by fungus
Fungi love wet and warm conditions (like those between your toes)
A mould grows on the skin surface, but this penetrates the skin
It causes scaling, flaking, itching leading to pain and inflammation
Antibiotics are needed

12. Protections Against Diseases
You body tries to keep harmful germs out of your blood in a variety of ways:
Your skin is a physical barrier
Your stomach is full of HCl
You eyes produce tears to wash away dirt
You have an immune system

13. What is the Immune System?
The body makes white blood cells and antibodies to detect and fight germs
These are made in the bone marrow
The move in the lymph vessels and fight disease in the lymph nodes
These are found under your neck, armpits and in your groin

14. White blood cells There are different types: Phagocytes attack germs
They eat them or use enzymes to kill them
Lymphocytes make antibodies
Each different germ needs its own antibody to recognize it (like a key for a door)
When they find the right antibody lots are made
This builds up immunity to the disease the next time you catch it