Health Science 1

The Immune System And Body Defense

I. Lines of Defense

A. First line of defense: Innate (born with this)

1. skin: acid pH

2. tears

3. sweat

4. own microflora: beneficial bacteria on your skin

5. stomach pH

B. Second line of defense: generalized, “whole-body’ response (innate)

1. Cells: White blood cells: neutrophils, eosinophils

2. Inflammatory response

a. redness

b. heat

c. swelling

d. pain

3. Fever: increase temperature to reduce number of infectious organisms

C. Third line of defense: acquired

1. Cells: B Lymphocytes (Humoral immunity),

T lymphocytes (Cell mediated immunity)

Macrophage

  1. B memory cells and T memory cells (relatively immortal)
  2. Bone marrow (B cell) vs. Thymus (T cell)
  3. Types:
  1. B cells, Plasma cells, B memory cells
  2. T cells: T helper, T suppressor, T killer
  3. Macrophage

II. Antigens vs. Antibodies

  1. Non-self: Antigens
  2. Antibody production
  1. How are antibodies made?
  1. Autoimmune diseases: self vs. non-self
  2. Allergies, asthma, and anaphylaxis: effect of stress

III. Infectious Disease: caused by pathogens (viruses, bacteria, molds and yeast, protozoans)

  1. Mode of Transmission
  1. Direct contact
  2. Indirect contact
  3. Droplet infection
  4. Transmission by insect vectors
  1. Epidemiology: frequency of the disease in the population
  1. Endemic: constantly in the population; most people make antibodies
  2. Epidemic: emergence of many cases of a disease usually in a geographic location
  3. Pandemic: world-wide distribution of the disease, influenza is an example.
  4. Sporadic disease: brief epidemic; localized
  1. Food borne disease: contaminated food or intoxication
  1. Improper storage of food (cold, eg)
  2. E. coli food poisoning
  1. Travel
  1. WHO (World Health Organization)
  1. Pandemic of Severe Acute Respiratory Syndrome (SARS)

March 2003-July 2003, spread worldwide, more than 8000 cases and 774 deaths in 26 countries. Coronavirus

  1. Malaria: Insect vector
  2. Zika: Insect vector
  1. STI’s
  1. Factors: partner variables, general health,
  1. Drugs:
  1. Hepatitis C

IV. Antibiotic Resistance

  1. Antibiotic Resistance
  1. methicillin resistant Staphylococcus aureus (MRSA)
  2. antibiotic resistance genes shared among bacteria

V. Infectious diseases

A. Global infectious diseases

1. Pneumonia:

a. leading cause of death in children after the first month of life

b. leading cause of death in low-income coutnries

c. third most common cause of death for all ages worldwide

d. Streptococcus: resistant to penicillin

2. Diarrhea

a. second leading cause of death among children under age 5

b. dehydration and electrolyte imbalances

c. rotavirus

3. Tuberculosis

a. Mycobacterium tuberculosis (TB) is the most common

infectious disease with approx.. 30% of world pop infected.

b. Increased number of infections of HIV

c. Close living quarters and poverty

d. Combination drug therapy

e. resistant strains

4. Malaria

a. mosquito borne

b. high fever and chills, sweats, headache, nausea and vomiting

  1. College campuses
  1. Staph skin infections
  2. Urinary tract infections (UTIs)
  1. Primarily E. coli

VI. Sexually transmitted infections

  1. HIV/AIDS
  1. first case in 1981
  2. pandemic has resulted in more than 20 million people worldwide
  3. Women in sub-Saharan Africa (59% of people with HIV infection)
  4. 1.2 million living with HIV in US.
  5. HIV targets macrophage and T-helper cells: primary infection virus

Replicates rapidly: 4-11 days and symptoms: fever, weight loss, fatigue which lasts for a few weeks. Goes into latency (asymptomatic for 2-20 years.

  1. Modes of transmission:
  1. Direct contact:
  1. Sexual contact: responsible for 88% of cases in US.
  2. IV drug use
  3. Contact with infected blood or body fluids
  4. Universal protection
  5. Mother-to-child transmission
  1. HIV testing: oral swabs or urine, blood
  2. Treatment/Management
  1. Antiretroviral agents
  2. Drug coctails
  1. Chlamydia: most common bacterial STI

1. 1.4 million cases annually

2. Young women are at greatest risk; all sexually active women should be checked annually

3. Men have a tendency to be more asymptomatic.

  1. Gonorrhea: 2nd most common bacterial STI

1. Highest rates are in women

2. Most men develop symptoms

3. Treated with antibiotics: many resistant strains

cephalosporings

  1. Syphilis: bacterial infection

1. Primary stage: chancre

2. Secondary stage: skin rash

3. Tertiary (Late stage): systemic involvement, organ systems affected.

  1. Human Papilloma virus (HPV): most common STI in US.

1. more than 100 strains of HPV; 40 strains associated with the genital area

2. HPV-16 and HPV-18 are associated with 66 % of cervical cancer cases

3. Transmitted via direct contact: vaginal or anal sex; oral sex, as well.

4. Most women will clear the infection within two years.

5. Vaccine available

  1. Genital Herpes

1. HSV-1 and HSV-2

2. Can infect the mouth, genitals or skin or cause lesions

3. HSV-2 infection may be asymptomatic

  1. Hepatitis: A,B, and C

1. A and B can be transmitted through sexual acts.

a. A can be transmitted via fecal-oral transmission

b. Vaccine available

2. Hepatitis B: sexually transmitted

3. Hepatitis C: IV drug use, STI

VII. Prevention of Infectious Diseases

  1. Support immune system: diet, reduce stress
  2. Cover cough
  3. Avoid touching mouth or face.
  4. Get vaccines as recommended.
  5. Minimize use of antibiotics,
  6. Minimize spread
  7. Travel Advisories
  8. ABCDs of STI prevention

A. Abstain

B. Be faithful: monogamous relationships

C. Use condoms

D. Detection of STI’s

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