1. Pathogens and Disease

2. Pathogens Pathogen=an organism that causes diseases
There are several methods used to transport pathogens

3. Methods for Pathogen Transport
Pathogen type
Transfer method A.
Airborne
Breathing (pass through lung epithelium) B.
Water borne
Drinking (pass through intestinal epithelium) C.
Foodborne
Eating (pass through intestinal epithelium) D.
Vector borne
Bite/sting (directly to blood stream) E.
Sexually transmitted
Intercourse/close contact (pass through skin) F.
Direct contact
Skin/saliva (pass through skin or into digestive tract)

4. Examples of pathogen types
Airborne pathogens
-can cause tuberculosis (a lung infection)
-symptoms: persistent cough, productive cough, coughing up blood, chest pain

5. B. Water borne pathogens
-can cause cholera
-found in water contaminated with human feces
-main symptom: diarrhea/death by dehydration

6. C. Food borne pathogens
-Salmonella comes from eating raw eggs, chicken, pork, etc.
Symptoms: sudden onset of nausea, abdominal cramping, and bloody diarrhea

7. D. Vector-borne pathogens
-Rabies
-Symptoms- paralysis, cerebral dysfunction, anxiety, insomnia, confusion, agitation, abnormal behavior, paranoia, hallucinations, progressing to delirium.

8. E. Sexually transmitted diseases:
-herpes (genital)
-syphillis
-gonorrhea
-human papillomavirus
-chlamidya
-bacterial vaginosis
-HIV
-and many more

9. F. Direct contact
-ringworm

10. Other examples of diseases caused by pathogens
Viruses: chicken pox, polio, HIV, influenza
Bacteria: tetanus, tuberculosis
Fungi: Athlete’s foot, ringworm
Protozoa: Malaria, sleeping sickness
Flatworms: Schistosomiasis=an infection caused by worms laying eggs inside a person

11. F. Roundworm: Elephantitis=caused by worms blocking the lymphatic system

12. Homework/Classwork Distinguish between HIV and AIDS. [2]
Discuss the cause, transmission, effects and social implication of HIV and AIDS. [9]
Explain why antibiotics are effective against bacteria, but not viruses. [4]
Due Friday

13. Antibiotics Antibiotics block protein synthesis in bacteria
Bacteria and animal cells synthesize protein the same way, but the proteins produced are not the same
Antibiotics use the differences to bind to or inhibit production or functions of new proteins
This prevents the bacteria from reproducing

14. Antibiotics (continued)
E. Antibiotics do not treat viral illnesses
-viruses are made of genetic material only
-they do not synthesize their own proteins
-viruses require a host to be alive

15. Antibiotic resistance in bacteria
Genetic mutations
-can be caused by chemical or radiation exposure or randomly
-bacteria that are not susceptible to the antibiotic continue to thrive and multiply

16. B. Example
You are prescribed antibiotics
You take them for two days and feel okay
You stop taking the prescription
Two days later you feel ill again
What happened?
You didn’t take the antibiotics long enough to kill all of the bacteria
All partly resistant bacteria had the chance to reproduce and possibly become more resistant