Disease Transmission

• Person to person contact

• Air

• Food

• Water

• Animal Bites

• Sanitation improved health

• Minimizing exposure decreases chances of infection

Koch’s Postulate

Resistance to Disease• Resistance to a particular disease is called Immunity

• Vaccination is a medical procedure used to produce immunity. A vaccine is a solution that contains a dead or weakened pathogen or genetic material from a pathogen.

• Viruses (like influenza) can change the appearance of their antigens in a process known as antigen shifting. This makes any previous immunity ineffective.

Autoimmune Diseases

Disease Areas affected Symptoms

Graves’ disease Thyroid Gland Weakness, irritability, heat intolerance, increased sweating, weight loss, insomnia

Multiple Sclerosis (MS)

Nervous System Weakness, loss of coordination, problems with vision and speech

Rheumatoid Arthritis Joints Severe Pain, Fatigue, disabling inflammation of joints

Lupus Connective tissue, joints, kidneys

Facial Skin rash, painful joints, fever, fatigue, kidney problems, weight loss

Type 1 Diabetes Insulin-producing cells in pancreas

Increases blood glucose levels, excessive urine production, problems with vision, weight loss, fatigue, irritability

Sexually Transmitted Diseases

HIV Infection• HIV infects Helper T cells to produce new

viruses. As WBCs die, the immune system becomes susceptible to secondary infections.

• HIV tests look for HIV antibodies• Time between infection and development

of AIDS may be greater than 10 years. • More effective drugs have increased

quality of life and life expectancy for HIV positive patients.

HIV Transmission

Lytic and Lysogenic Cycles

Allergic Reactions

• An allergy is the body’s inappropriate response to a normally harmless antigen

• Most allergies are simply uncomfortable, but some can be fatal if not treated immediately.

• Most allergy medications contain antihistamines, which block histamine and prevent swelling and redness