INFECTIOUS DISEASES

CHAPTER 21(11)

Infectious DiseaseCommunicable

Can spread easilyCaused by organisms that multiple within us

Micro-organism

CAUSES OF INFECTIONS PATHOGENS

1.BACTERIA• Simple, single cells organism, that can live

almost anywhere.• TOXINS – poisons

2. VIRUSES• Bundle of genes wrapped in protein

cover

• Virus factory

3. FUNGI• Simple organisms related to mold• Like warm, dark, and moist areas

4. PROTOZOANS• Moves through fluids in search of food

5. OTHER PATHOGENS• Diseases caused by animals, insects and

parasitic worms

PATHOGENS ARE SPREAD BY:

1. CONTACT with INFECTED PERSONS: direct contact, indirect contact

2. CONTACT with CONTAMINATED OBJECTS.

3. CONTACT with INFECTED ANIMALS/ INSECTS.

4. CONTACT with ENVIRONMENTAL SOURCES.

BODY’S DEFENSES:

1. PHYSICAL & CHEMICAL DEFENSES A. SKIN – largest organ on the body

• Pores are exits• Secretes sweat – which is poisonous to germs• Secretes oil – called Sebum

Body’s Defenses (cont.) PHYSICAL & CHEMICAL DEFENSES

B. MUCOUS MEMBRANES – protective lining• Secretes mucus; traps pathogen • Chemicals within it kills pathogen

Cilia – tiny hair like structures

* removes pathogens

Body’s Defenses (cont.) PHYSICAL & CHEMICAL DEFENSES

C. Saliva and Tears – washes away pathogens

D. Digestive System – removes/excretes pathogens

Body’s Defenses (cont.)

2. INFLAMMATION: BODY’S RESPONSE TO ALL KINDS OF INJURY

• Damaged cells release chemicals that cause blood vessels to enlarge

• Allows more blood flow – carries nutrients and white blood cells to area

• Phagocytes – white blood cells

Body’s Defenses

Infected area becomes red, swollen and sore

Pus – white liquid that is an accumulation of fluids, white blood cells and dead cells.

Phagocytosis

Body’s Defenses (cont.)

3. IMMUNE SYSTEM – made up of blood, bone marrow and

lymphatic tissue

LYMPHATIC SYSTEM – is a network of vessels that form the immune system.• Has three structures

Three lymphatic structures

LYMPH – the fluid that flows through the lymphatic system

LYMPH NODES – small stations that houses different white blood cells

LYMPHOCYTES – specialized white blood cells Some patrol the body Some are dormant in the lymph nodes

3 TYPES OF LYMPHOCYTES

1. B LYMPHOCYTES – B CELLS 2. T LYMPHOCYTES – T CELLS

A. Helper T B. Killer T C. Suppressor T

3. MEMORY CELLS

1. B LYMPHOCYTES B CELLS –

produces antibodies ANTIBODIES –

are Y-shaped proteins that attach themselves to pathogens

Form memory cells

2. T LYMPHOCYTES (T CELLS)

A. HELPER T CELLS Produces

chemical that regulates the activity of the other white blood cells

Interferon – chemical that stimulates phagocytes

B. KILLER T CELLS Kills pathogens

directly by destroying the infected body cells

T Cells (cont.)

C. SUPPRESSOR T CELLS

SLOWS DOWN THE RESPONSE OF THE B CELLS AND THE T CELLS

3. MEMORY CELLS

FORM AFTER HAVING AN INFECTION FORM THROUGH VACCINATIONS

ARE STORED IN THE LYMPH NODES

Immunity

The body’s ability to fight infection.

Active – having infection• - Vaccination – injection of of disabled or dead

pathogen.

Passive – immunity through an outside source

STAGES OF INFECTIONS

1. INCUBATION STAGE – time between, when the pathogen enters the body and makes you sick. Every pathogen has a different

incubation period

2. PRODROMAL STAGE – when the first symptoms occur Sore throat, sneezing, etc.

Stages of infections (cont.)

3. ACUTE STAGE – symptoms are most severe. Fever

4. RECOVERY STAGE – start to feel better. Convalescence – period between end

of infection Relapse – illness returns

MEDICATIONS ANTIBIOTICS – drugs that kill bacteria

Penicillin Erythromycin Tetracycline Bixan

Take it exactly as directed. Always take the exact amount that the label says to take. If the label says to take the medicine at a certain time, follow these directions.

Take it for as long as prescribed.

Medications

75% of antibiotics prescribed for respiratory tract infections

50% of antibiotic prescriptions are inappropriate

Most respiratory tract infections are caused by viruses

Antibiotics do not work against viruses

What Are Antivirals?www.webmd.com)

Antivirals are medications that reduce the ability of flu viruses to multiply.

The CDC considers antiviral drugs as a "second line of defense against the flu.

"When taken at the onset of flu, these medications help decrease the severity and duration of flu symptoms.

USING MEDICATION CORRECTLY

Tell doctor of any medicine you are taking Tell doctor of any drugs taken within 24hr. Ask how medicine should affect you Store medications correctly Read information of label, or print out Take medication prescribed to you only

Cont. Tell doctor of any side effects NEVER drink alcohol with

medication, this includes over the counter meds.

Throw away old medications.

MEDICAL PROFESSIONALS

PHARMACOLOGISTS NEEDS PH.D WORKS IN

RESEARCH LAB. TO DEVELOP NEW DRUGS TO TREAT OR PREVENT DISEASE.

PHARMACIST NEED 5 YR.

COLLEGE PROGRAM

AND STATE LICENSE

DISPENSES MEDICINES THAT HAVE BEEN PRESCRIBED BY DOC.

ORGANIZATIONS: CENTER FOR

DISEASE CONTROL - CDC

WORLD HEALTH ORGANIZATION - WHO