Infectious Diseases

What Causes Infectious Disease? Pathogens: Any virus or microorganism found in the body that does not belong there and can multiply causing destruction of vital cells and organs.

Types of Pathogens Bacteria: Simple, single celled microorganisms. Most are not pathogens, some of which are necessary for healthy body functions. Bad bacteria release a poison known as toxins which can damage cells. Bacterial infections are treated with anti-biotics.

Types of Pathogens Viruses: Very small pathogen, 100 times smaller than bacteria. It is not a living organism and can only multiply by entering a living cell. No known cure for viruses, only immunizations are available. Once you get a viral infection it is too late and the body is on its own.

Types of Pathogens Fungi: Organisms such as yeasts,mold and mushrooms. They grow in dark, warm and moist areas. Ringworm and athlete’s foot are good examples. Protozoa: Single celled organism much more complex than bacteria. Moves through liquid in food. Malaria and dysentery are examples of diseases caused by protozoa.

Types of Pathogens Mites, lice, and certain types of worms are other types pathogens.

Lines of Defense First Line of Defense: Physical and Chemical Second Line of Defense: Inflammation Third Line of Defense: Immune System

Immunity Passive immunity: Receiving antibodies from a source other than your immune system, i.e. mother’s breast milk, vaccines. Active immunity: Naturally developed antibodies after initial exposure to disease or vaccination.

Immunity Immunizations: An immunization is the process by which a person or animal becomes protected from a disease Vaccine: An injection of a killed or weakened organism that produces immunity in the body against that organism

Lymphatic System A network of vessels that collect fluid from your tissue and then return it to the blood stream. This fluid is known as lymph. The lymph nodes (stations) act as a filter. Phagocytes and lymphocytes are present in the lymph nodes and attach pathogens as they pass through. Save some writing. Read p. 556.

Common Bacterial Diseases Strep Throat Lyme Disease Bacterial Meningitis Tuberculosis Any others? Bacterial diseases are treated with anti-biotics; drugs which kill or inhibit bacterial growth.

Common Viral Diseases Common Cold Influenza (flu) Pneumonia (bacterial and viral causes) Hepatitis (all types)

Prevention WASH YOU HANDS! Do not share personal hygiene items, drinks, towels, etc. Avoid close contact with those who are ill. Cook your food thoroughly. Stay home when you are not feeling well. Exercise regularly and eat healthy. Avoid alcohol, tobacco and other unhealthy substances.

Epidemics/Emerging Disease Avian Flu SARS (Severe Acute Respiratory Syndrome) Yellow Fever Dengue Fever West Nile Virus- caused by mosquito bites MRSA (Staff infection)