1. Early Scientist and Communicable Diseases
A communicable disease is a disease that is spread from one person to another.
An epidemic is the rapid spreading of a disease to a large number of people.
Great Plague of London: Bubonic Plague
A. Caused by unsanitary conditions
1. dirty streets
2. crowded houses
3. poor personal hygiene

2. B. 70,000 people died in 7 months.
C. Many people left London.
D. Extreme measures were made to get rid of disease
1. Quacks (phony doctors) sold fake pills.
2. People who had contact with the sick had to carry a white stick.
3. Infected houses were marked with a flag or cross on the door.
4. Locked infected people inside house for a
2 week period.
5. Large fires were built in streets to “clean the air”

3. Jamestown Colony
A. In 1606 Colonists settled near James River in Virginia
B. First settlement was Jamestown
C. Health problems arose in summer of 1607
1. weather was hot and humid
2. food spoiled
3. water was contaminated with germs
4. half of the 104 settlers died by end of summer

4. D. Later colonists in North America died of many diseases
1. Half of the children died as babies
E. Colonists believed that evil spirits caused disease
1. tried magic and strange remedies
2. Person was thought to be cursed if they weren’t cured
3. No scientific knowledge about how disease was spread
Cause of Communicable Disease
A. Germs cause disease

5. B. Microbes are tiny organisms that can only be seen with a microscope
C. Types of Microbes:
1. bacteria
2. viruses
3. protists
4. fungi
D. Harmful Microbes = 5 %
E. Helpful Microbes
1. turn milk into cheese
2. turn cider into vinegar
3. make medicines called antibiotics
4. make foods like pickles, by fermentation

6. Scientists
A. Antony van Leeuwenhoek
1. cloth merchant from Holland
2. make 200 lens in his spare
time
3. 1st scientist to see microbes
with his microscope
4. Did not know that the “tiny animals” caused disease
B. Lazaro Spallanzani
1. Italian scientist
2. Explained how microbes spread (multiply)
3. One microbe splits into 2 every minutes.

7. C. Edward Jenner
1. English doctor
2. Proved that cowpox and smallpox were similar
3. Cowpox is a mild form of smallpox
4. Used the fluid from a cowpox sore to make a vaccine for smallpox
5. Made the first successful vaccine
D. Louis Pasteur
1. 1st scientist to make the
connection between germs and disease
2. Discovered that germs could be killed at high temperatures, which is called pasteurization

8. 3. Saved the silkworm industry – found the microbes that were killing silkworms and stopped the disease
4. Saved French livestock industry from anthrax
5. Proved that vaccination provides immunity because the body creates antibodies to fight off disease
6. Created a vaccine for rabies by using the spinal cords of dogs that had died of rabies
E. Joseph Lister
1. Scientist from Scotland, called the Father of Antisepsis
2. Discovered that microbes could cause infection in a surgical wound.

9. 3. Discovered that cleaning a wound eliminated infection, a method called antisepsis
4. Discovered that a clean operating room led to few infections after operations, a method called asepsis
5. Used germ-killing drugs and chemicals called antiseptics
F. Paul Ehrlich
1. Found a compound of arsenic that would kill germs that caused syphilis
2. Called what he was looking for the “magic bullet”
3. Began the Age of Chemotherapy, the use of chemicals to kill disease germs

10. G. Alexander Fleming
1. Accidentally dropped mold into his experiment of bacteria
2. Discovered that penicillium, a type of mold, can destroy certain types of bacteria
3. Called the substance penicillin, which destroyed germs that cause strep throat, blood poisoning, and some
types of pneumonia
4. Penicillin was the first of many antibiotics made from molds found in the soil

11. Death Rates and Life Span
A. Over the last 100 years there has been a decrease in the amount of people who die from communicable disease
B. People are also living longer
because of modern medicine, sanitary living
conditions and vaccinations we receive at birth to
protect us against deadly disease.
Immunity
A. Active Immunity – natural resistance to disease
1. Material enters the body

12. 2. Lymphocytes respond to the material called antigens
3. Lymphocytes (specialized white blood cells) make proteins called antibodies to respond to the antigen
4. Antibodies cause antigens to become inactive.
B. Passive Immunity – a resistance to a disease that requires a vaccination.
1. Vaccination is the injection of substances into the body to help protect it against disease.
2. Vaccine – substance injected into
the body to protect against disease.