BPK 140 Lecture Notes - Lecture 4: Disinfectant, Stainless Steel, Absenteeism

• School: Simon Fraser University
• Department: Biomedical Physio & Kines
• Course: BPK 140
• Professor: Mike Walsh

Document Summary

The fifth link in the chain of infection is the portal of entry and is usually the same as the portal of exit. Such sites of exit and entry are the digestive, reproductive, or respiratory systems. Some pathogens are capable of cross portal entry. The hiv virus can cross between the digestive and reproductive systems when oral or anal sex is involved: the new host. The new host is now infected with the pathogen. The relative virulence of the disease will depend on the strength of the new host"s immune system: interesting feature. The 6 stages of the chain of infection are not necessarily passive . Remember that some pathogens make humans cough and sneeze. A more interesting behavioural example that supports the "parasite manipulation hypothesis" is when monkeys are infected with a protozoan (toxoplasma gondii). Remarkably, the pathogen makes monkeys attracted to leopard urine, the mortal enemy of monkeys.