INFECTIOUS DISEASES Chapter 15 Pg. 400. INFECTIOUS DISEASE Diseases caused and transmitted from...

INFECTIOUS DISEASES

Chapter 15Pg. 400

INFECTIOUS DISEASE

Diseases caused and transmitted from person to person, by microorganisms or

their toxins. • Also called communicable or

contagious diseases.

What do you think? ■A hospital is a place where people can

easily pick up infectious diseases.– TRUE

■Antibiotics are among the few medicines that are effective against viruses. – FALSE. Antibiotics are useful

against bacteria, not viruses.

■Fevers are dangerous, especially when people have infections. – FALSE. Fevers are part of the

body’s defense against infection, and low fevers are not dangerous.

MicroorganismsBacteria

■Single celled organism.

■Grows/multiple in warm dark, moist environments.

■EX: – Tetanus– Tuberculosis– Lyme Disease

Viruses

■Not a cell, genetic material that can invade living cells – even bacteria.

■EX: – Influenza– Chicken Pox– Shingles– Pneumonia– Polio– Measles – Mumps

■ Pg. 404, Figure 15.4

Types of Bacterial Diseases■Tetanus – toxin produced by

bacteria within a wound. – Vaccine provided.

■Tuberculosis – bacterial infection of the lungs.

■Lyme Disease – bacterial infection spread by tiny deer ticks.

Other Pathogens that cause a variety of diseases.

■ Fungi ( yeast or molds)– Athletes foot

■ Protozoa

■ Parasites

■ Worms– Head lice

Mononucleosis “The kissing disease”

■Viral infection that resembles an upper respiratory infection. – Spread through saliva

■Symptoms – severe sore throat, fever, swollen glands, enlarged spleen, and infected liver.

■After full recovery, mono will not strike the same person again.

The Body’s Defenses

■First line of DEFENSE: – Skin – produces salty, acidic

sweat, which repels pathogens. It also have one-way pores that let toxins out, but won’t let pathogens in.

– Membranes – Mucus and chemicals.

Body’s Defenses continued

Demonstration

Antigen “ foreign invader” / FLU

T-cell “recognizes invader” and sounds an ALARM!

B-cells arrive and record shape of invaders. Then make antibodies.

Antibodies made so invader is remembered

and can be destroyed right

away.

HIV/AIDS HIV/AIDS

Antigen “ foreign invader” / HIV

T-cell “HIV hides inside cell, which remains safely away from immune system”

HIV multiplies as FAKE T-cells & invades more T-

cells.

After months or years, the

infection begins to destroy

immune system. All T-cells are

being destroyed.

INFECTIOUS DISEASE VIDEO

http://www.youtube.com/watch?v=M1pUoYBbEpI

Another way to FIGHT■Swelling of lymph nodes

■Fever– Cold viruses thrive and

multiply at temperatures between 86-95 degrees, but die off at higher temperatures.

– Activates immune system.

Food Infection/Poisoning■Salmonella – food borne pathogen

causing digestive system infections.

■Botulin Toxin – poison produced by bacteria in sealed cans, plastic packs, or jars or food.

■E.coli – toxin producing bacteria that can cause food-borne illness.– Diarrhea, severe cramps,

dehydration, and kidney damage.

Preventing Food-borne illness. ■Clean

– Hands– Wash cooking items in HOT water.

■Separate– Utensils to prepare different types of food. – Raw vs. cooked food.

■Cook– Meat & Seafood – 145 degrees– Ground meat – 160 degrees

■Chill– Do not eat cold dishes that have been in room

temperature for 2 hours or more – or 1 hour in hot weather.