Pathogens and Disease

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

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)

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

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

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

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

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

F. Direct contact -ringworm

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

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

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

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

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

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

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