Introduction to Disease

Transcription

1 Introduction to Disease

2 What is a pathogen? Disease-producing microorganism and toxin

3 VIRUS Viruses exist for one purpose only: to reproduce. To do that, they have to take over the reproductive machinery of suitable host cells. Can be transmitted through air, food, water, body or sexual contact, and contact with contaminated surfaces.

4 VIRUS Diseases caused by a virus can not be cured, but the symptoms can be treated. Vaccines can also be administered. Examples: Ebola, HIV, HPV (Genital Warts)

5 BACTERIA Bacteria live on or in just about every material and environment on Earth from soil to water to air, and from your house to arctic ice to volcanic vents. Each square centimeter of your skin averages about 100,000 bacteria. A single teaspoon of topsoil contains more than a billion (1,000,000,000) bacteria.

6 BACTERIA Bacteria can be spread from person to person in many ways. Through air, food, water, body or sexual contact, and contact with contaminated surfaces.

7 BACTERIA Can be treated with an antibiotic. Many to most diseases caused by bacteria can be cured with an antibiotic. Examples: E.coli, strep. throat, TSS, pink eye.

8 FUNGI Fungi include singlecelled creatures that exist individually the yeasts and multicellular bunches, such as molds or mushrooms. Fungi usually grow best in environments that are slightly acidic

9 FUNGI Fungi absorb nutrients from living or dead organic matter (plant or animal stuff) that they grow on. Some fungi are quite useful to us. (Bakers yeast and antibiotics)

10 PROTISTS: PROTOZOA The word protozoa means "little animal." Perhaps the best-known protozoal menace is Plasmodium <plaz-modee-um>, the parasite that causes malaria. This terrible disease leads to about 800,000 deaths each year worldwide.

11 Parasitic Worms Tape Worm Hookworm Pinworm

12 Rocky Mountain Fever Lice

13 The Course of a Disease 1. Incubation Invasion of the pathogen.may not know you re sick 2. Prodrome - Onset of symptoms 3. Clinical Immune system in full battle 4. Decline Pathogen almost killed off. Memory cells develop 5. Convalescence Repair of the body, body returns to normal.

14 T-Cells and B-Cells 1. Invaders (pathogens) enter body 2. T-Cells (from Tyhmus Gland) recognize there is an invader 3. T-Cells call on B-cells to help make antibodies to kill off invader. 4. Antibodies kill off invader and store in memory the type of invader (pathogen) so the next time they come back they are more easily killed off.

15 Chain of Infection Pathogen The organism that is capable of causing illness Reservoir a "place to live", usually a human or animal (host) Place of Exit A way out, humans = body openings; droplets in person containing pathogen, LIKE A SNEEZE

16 Chain of Infection Method of Transmission must have a way to travel to its host Port of Entry must find a way to get INTO the new host Susceptible Host Someone/thing that has little or no resistance to the pathogen

17 Ways to break the link of Infection Kill the Pathogen (Medicine) Prevent contact (quarantine) Prevent Escape (Cover your mouth when you cough) Prevent Transmission (control disease) Block the Ports (Band-Aids, Kleenex, cover mouth) Resistant Host: stay immune