Biotechnology I Infectious Diseases

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?

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

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

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

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

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

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!!!

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

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

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

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

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

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