ENH 122 Lecture Notes - Lecture 5: Subclinical Infection

• School: Ryerson University
• Department: Environmental Health
• Course: ENH 122
• Professor: Jordan Tustin

Document Summary

Agent > reservoir > mode of transmission > susceptible host. Increase in any of the above increases incidence. Sporadic occasional cases occurring at irregular intervals. Triangle (top = host, left = agent, right = environment, centre = vector) Remove a key play (vector) and transmission is usually broken. Vector borne: living species as carrier or even intermediate host. Airborne: dissemination of microbial aerosols to a portal of entry, usually the respiratory tract. Top = clinical illness (cells damaged or dysfunctional) clinical illness moderate or severe. Middle = subclinical infection (agent replicates or multiplies), no clinical illness. Bottom = subclinical exposure (no attachment, no invasion) no damage.