Communicable Disease Disease passed from one person to another

Infectious Disease 5 main kinds of Germs 1. Virus »Most common, invade healthy cells and reproduce »Can not survive outside host cell »Resistant to antibiotics »We can treat symptoms, but the body must fight off the disease on its own »Vaccinations prevent and are the most effective Examples are colds, flu, chicken pox, measles, mumps

2. Bacteria »Self-reproducing germs without host cells. They get in the body and multiply »Some are helpful and some cause sickness. »Most bad ones can be killed with medicine/ antibiotics by eating away the cell membrane Examples are strep throat, pinkeye

3. Fungi »Protective capsules surround the cell wall and protect from phagocytes »Usually easily treated with medicine Examples are athletes foot, ringworm

n 4. Protozoa - Mainly transmitted by bug bites Ex. Malaria, lyme disease n 5. Rickets- Animal like organisms in bad water.

What Diseases Need To Make Us Sick n Host susceptibility –Age- Young and old more suseptible –General health, immune status –Risk behaviors –Prevention behaviors

Route of Transmission n Portal of entry –Nose, Mouth, Cut, Skin »Exposure does not always equal infection –Direct- Skin to skin contact –Indirect- Airborne (sneezes/coughs), sharing drinking glasses –Vectors/carrier- Animal or bug bites, –Vehicles- Contaminated food, water

How Sick Will I Get? n Depends upon: –How strong the germ is –Dose of infectious agent –Resistance/immunity of host –Mode of entry n All must exist to create risk n Exposure does not mean person will become infected

4 Disease Stages n 1. Incubation/Infected Period –Period of infection, illness cannot be transmitted to another host –Symptoms start to build n 2. Infectious Period –Period after an infection when agent can be transmitted to another host –Symptoms start to show: Cough, Sneeze, Fever

Disease Stages 3. Disease/Sick Period –When the illness sets in –Person displays all symptoms n 4. Recovery Phase –Start to feel better –Body overcomes disease and immunity develops

Infected Infectious Sick Recovery Infected Infectious Sick Recovery

The body’s defense system against disease The body basically has 3 Lines of Defense 1st Line -Skin- Protective barrier -Mucous membranes- Nose, throat, eyes trap and eliminate germs by coughing and sneezing -Saliva -Tears -Stomach acid 2nd Line -Rising body temperature (fever) -White blood cells- Phagocytes surround and kill germs -Interferon- A chemical released by WBC’s to stop the spread of viruses IMMUNE SYSTEM

3rd Line- The Lymphatic System- Carries lymphocytes which destroy invaders T-cells- The brains of the system Memory T-cells- Remember what a disease is so we can’t get sick with it again. B-cells- The workers of the system, eat and destroy germs Other- Antibodies- Stay in your system and fight disease Immunity- Body’s ability to resist germs

Immunization/Vaccines and Antibiotics n Vaccines- A small or dead dose of a disease that builds antibodies. Prevention of any illness is always better than treatment n Antibiotics- Powerful medicines that fight bacterial infections. n