1. Biotechnology I
Infectious Diseases

2. Essential Question
How is an infectious disease different from a genetic or metabolic disease
What microbes are associated with infectious disease?
What is the difference between emerging and re-emerging infectious diseases?

3. Disease
Definition: Anything that can impair normal tissue function in the human body

4. Classification of Disease
Two types
Genetic or metabolic – physiological disruption of tissue function
Ex. Cystic fibrosis: abnormal production of thick mucus because of impaired chloride transport across cell membranes.
Ex. Atherosclerosis –Plaques of cholesterol have built up and partially blocked arteries – lead to heart attacks and strokes

5. Classification of Disease
Two Types
Infectious disease – caused by the invasion of the host by agents that harm host’s tissues (i.e. disease) and can be transmitted to other individual’s (i.e. infectious)
Ex. Measles virus

6. PROPERTY OF PIMA COUNTY JTED, 2010
Think-Pair-Share
Why is atherosclerosis not considered an infectious disease? Be ready to share
3. Think-pair-share
teacher presents a question
teacher gives wait time for student to form answer
teacher instructs students to share their answer with a partner
teacher calls on non-volunteers to share with the class
PROPERTY OF PIMA COUNTY JTED, 2010 3

7. Pathogens Microorganisms that cause disease Classified as either
Bacteria- unicellular prokaryotes.
Ex. Salmonella typhi – causes typhoid fever
Viruses – not living organisms- no metabolism and cannot reproduce on their own
Ex. Ebola virus
Fungi-eukaryotic, heterotrophic
Ex. Ringworm; certain types of yeast
Protozoa –unicellular, heterotrophic eukaryotes
Ex. Plasmodium that causes Malaria

8. Infection and Disease not synonymous
Infection –pathogen invades and begin multiplying in host
Disease- when the pathogen causes harm to host tissue
Infection does not always result in disease!!!

9. How Pathogens enter the Body
Enter at one of four sites
Respiratory tract (mouth, nose) Ex. Influenza virus
Gastrointestinal tract (mouth oral cavity) Ex. Vibrio cholerae which causes cholera
Urogenital tract Ex. E. coli causes cystitis
Breaks in the skin Ex. Clostridium tetani which causes tetanus

10. Causing Illness To make us ill, microbes have to Reach target tissue
Attach to target site to infect
Multiply rapidly
Obtain nutrients from host
Avoid and survive attack by the host’s immune system

11. Infectious Diseases
What are some past and current cause of death and illness associated with infectious diseases?

12. Infectious Diseases classified as
Emerging infectious diseases
Have not occurred in humans before
Ex. Hantavirus pulmonary syndrome
Occurred previously but only affected small numbers of people in isolated areas
Ex. Ebola virus
Have occurred throughout human history but only recently has been recognized as a distinct disease caused by an infections agent
Ex. Lyme disease

13. Infectious Disease is classified as
Re-emerging infectious diseases
Once major health problems in particular country then declined dramatically
Recently have reappeared -caused renewed health problem
Examples
Tuberculosis- pathogen become resistant to antibiotics
Malaria – vector mosquito that carries the pathogen become pesticide resistant
Measles – failure to vaccinate

14. Class Activity Take Five Disease Cards and classify Infectious agent
Mode of transmission
Emerging or RE-emerging disease
Complete Chlorea Pogil