10/11/11 – Evolution of virulence
Key evolutionary concept: mode of transmission of a parasite or pathogen can affect the evolution of virulence.
Key evolutionary concept: public health efforts and hospital characteristics have the capacity to influence the evolution of virulence traits.
Vector-borne diseases and virulence
Hospital Acquired Infections – are medical workers vectors of disease?
Do pathogens evolve toward commensalism?
1. Evolution of virulence. Ewald PW. 2004. Infect Dis Clin N Am (18) 1-15.
Writing project (due next week)
a) Dengue fever incapacitates many of its adult victims. Does immobilization help or hurt the transmission of the virus? How is dengue different from the common cold?
b) Why do “hospital-acquired” infections get different antibiotics than “community acquired” infections. Which are generally worse and why?
Some illnesses make you feel bad, but you can still go about your business: e.g upper respiratory infections caused by rhinoviruses. Other infections wipe you out and you can’t get out of bed. Is it in the rhinovirus’s best interest (so to speak) to keep infected hosts in bed? What symptoms associated with common cold facilitate transmission of the virus? What is the best public health directive for colds: 1) go to work as usual. 2) go to the urgent care center for a work note. 3) stay at home