1. PHARMACY TECHNICIAN
CHAPTER TWENTY SEVEN

2. Nonspecific Defenses
Considered a “first line of defense” against disease and infection
Nonspecific defense mechanisms include:
Physical barriers (unbroken skin)
Natural deterrents (fluids and immune cells that attack invaders)
Inflammatory process 2

3. Specific Defenses
Specific defense mechanisms are called the immune system
Immune system has specialized molecules and cells that fight foreign invaders
Immune system molecules consist of two types of protein molecules:
Antibodies—identify foreign particles
Complement—destroys foreign particles 3

4. Parasites
Multicellular organisms or single-celled organisms that are not bacteria or fungi
Asymmetrical symbiotic relationship:
Parasite benefits from host
Host receives no benefit from or is harmed by relationship
Most common parasites in the United States are:
Pinworms
Roundworms
Tapeworms
Transmission usually occurs via ingestion of contaminated food or soil 4

5. Bacteria and Virus Bacteria Virus
Unicellular, prokaryotic microorganisms
May be round (coccus/cocci), rod (bacillus/bacilli), or spiral-shaped
May cause disease; may also have beneficial relationships (E. coli, etc.)
Virus
Ultramicroscopic infectious pathogen
Can replicate itself only within cells of a living host
Uses the DNA and RNA of the host
Antibiotics are ineffective against viruses 5

6. HIV (Human Immunodeficiency Virus)
Can be categorized as either HIV-1 or HIV-2
Most references to HIV refer to HIV-1, the most common worldwide
Both types are transmitted:
By sexual contact
Through bodily fluids
At birth from mother to child
Both types of HIV cause clinically indistinguishable AIDS
Acquired immune deficiency syndrome
Immune system becomes severely suppressed
Body cannot fight opportunistic infections or cancers 6

7. Five Stages of HIV Progression to AIDS
Stage 1—initial transmission and infection with HIV
Stage 2—infected without presentation of signs or symptoms (10 or more years)
Stage 3—signs and symptoms of HIV begin to appear
Stage 4—AIDS opportunistic infections lead to a CD4 cell count or level below 200 per cubic millimeter of blood
Stage 5—last and final stage of wasting to death 7

8. Classes of HIV Drugs Vaccine Not yet developed
Would enable immune system to destroy HIV before infection occurs
Attachment inhibitors
Would prevent HIV from attaching to host cells
Inhibitors
Block the synthesis of copies of the viral RNA
Virus cannot duplicate itself 8

9. Autoimmune Disease
Occurs when immune system mistakenly attacks the cells, tissues, and organs of its own body
Immune system cells and molecules accumulate at a target site
This gathering is broadly referred to as inflammation
Autoimmune diseases are not contagious and are not related to AIDS or cancer 9

10. Drug Resistance
Defined as a microorganism’s ability to live and grow in the presence of an anti-infective or antimicrobial drug
Is a result of genetic mutation during cell division
Allows the pathogen to evade or avoid the destructive mechanism of a drug
Bacteria are especially prone to develop drug resistance
The increasing use of antibiotics contributes to this action and is called antibiotic resistance 10

11. Preventing Antibiotic Resistance
Avoid unnecessary antibiotic use in humans
Avoid unnecessary antibiotic use in animals
Use most specific antibiotic possible
Complete an antibiotic regimen (no leftover pills)
There may be no ultimate cure for antibiotic resistance
However, development of resistance can be slowed down 11

12. Anti-Infectives
Umbrella name under which various types of drugs are then subclassified
Also called antimicrobial—against the growth of a microorganism or microbe
Antibacterials—treat bacteria only
Antivirals—treat viruses only
Antifungals—treat fungi only
Metronidazole—amoebicidal, bactericidal, and trichomonacidal 12

13. Tuberculosis Caused by Mycobacterium tuberculosis bacterium
May attack any part of the body, but usually attacks the lungs
Spread by breathing air into which infected people have coughed or sneezed
Drug of choice for treatment is isoniazid (INH)
Taken for at least six to nine months
Longer if the patient has a weakened immune system 13

14. Malaria Transmitted by parasites found in malaria-infected mosquitoes
Can be cured with prescription drugs
Type of drug used and duration of treatment depend on:
Which type of malaria is diagnosed
Where the patient was infected
Age of the patient
Orogression of the disease at the start of treatment 14