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Tree Man. Born with an immune system disease Not what causes the growths! Infected by a virus, & couldn’t fight the virus. Dede Koswara Update (Tree Man). In 2008, Dede underwent surgery & doctors cut off 13lbs. of warts/decaying matter using an electric saw.
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Tree Man • Born with an immune system disease • Not what causes the growths! • Infected by a virus, & couldn’t fight the virus
DedeKoswara Update (Tree Man) • In 2008, Dede underwent surgery & doctors cut off 13lbs. of warts/decaying matter using an electric saw. • Unfortunately, Dede’s warts grew back. Click here for Tree Man’s story!
What exactly is a disease? • A condition in which the body is not functioning normally Sickle Cell vs. Normal Red Blood Cells
What causes disease? • Dietary: deficiency in calories, minerals, or vitamins • Goiter, Scurvy, Rickets
Rickets is the softening of bones in children due to deficiency of vitamin D, phosphorus, or calcium. This can lead to fractures or deformity. This woman has goiter, which causes her neck to become enlarged. It is caused by an iodine deficiency.
What causes disease? • Genetics: inherited diseases • Hemophilia, Down Syndrome, PKU, High Cholesterol Down Syndrome is caused by an extra chromosome 21 (trisomy 21).
What causes disease? • Venoms/Toxins: from plants, snakes, etc. • Sea Snake, Brown Recluse Spider, Poison Ivy Brown Recluse Spider
What causes disease? • Infection from microorganisms • Bacteria, Viruses, Protists, Fungi, Worms Tapeworms are parasites that can live in our intestines!
History of Disease • Many (hundreds) years ago, physicians described the body as having “humors” that needed to be in balance • If one part was “bad”, you let it out • Bloodletting Bloodletting is the withdrawal of small quantities of blood from a patient to cure or prevent illness & disease. Many believed that a woman’s menstrual cycles were meant to cleanse the body of bad humors.
Important People in the History of Disease • IgnazSemmelweis(1844): baby delivery suggestions • Suggested the doctors wash their hands • Reduced mortality from about 35% to about 1% • Dr. John Snow (1854): inspired by Semmelweis • Noticed that Cholera patients all drank water from the same pump from the Thames River • Closed the pump & the epidemic ended in 24 hours
Important People in the History of Disease • Dr. Joseph Lister (1867): sterile surgery • Used carbolic acid to sterilize operating rooms • 50% mortality dropped to 10% mortality Fun Fact! Listerine mouthwash was named after him in 1879!
Important People in the History of Disease • Robert Koch (1880): studied Cholera, Tuberculosis, & Anthrax • First to propose the idea that these diseases were caused by microorganisms! Dr. Koch is considered to be the founder of Microbiology! Fun Fact! There is a crater on the moon named after him, the Koch Crater!
Koch’s Postulates: method for finding the actual cause of a particular disease • The pathogen should always be found in the body of a sick organism, but not a healthy one. • The pathogen must be isolated & grown in the lab. • When the cultured pathogens are placed in a new host, they should cause the same disease as the original host. • The injected pathogen should be isolated from the second host, & it should be identical to the original pathogen.
Koch’s Postulates • Identify pathogen from sick organism • Grow pathogen in pure culture • Place pathogen in new host (should get same disease) • Isolate pathogen again (should be identical to original host)
Agents of Disease • Bacteria • Viruses • Protists • Worms • Fungi How do they spread? A protist, Plasmodium, causes Malaria!
Spread of Disease – Person to Person • Horizontal: • Exchange of body fluids (blood, semen, saliva) • Airborne disease • Indirect (touching surfaces) • Vertical: mother to child • Syphilis, herpes, rubella
Spread of Disease • Contaminated food & water • Sewage (E. coli, Cholera) • Protists (Amebic Dysentery) • Animal Carriers (Vectors) • Insects (Malaria, Lyme Disease) • Mammals (Rabies) The Rabies Virus is transmitted from an infected animal’s saliva with a bite wound. It causes inflammation of the brain.
Epidemiology • The science of how diseases occur & spread • Epidemic: sudden increase of a disease in a region • Pandemic: world-wide epidemic • Endemic: constant low-prevalence of a disease (common cold) • Outbreak: sudden unexpected occurrence of a disease in a limited demographic
Epidemiology • If you’re an epidemiologist, these are the questions you might ask: • Who is at risk? • What behaviors put you at risk? • What is the infection rate? • What is the mortality rate? • How is this disease prevented?
Before you leave… • Answer the following question on the back of your handout: What are some ways we prevent the spread of disease? Name at least 3, and explain how they work.