BIOL208 Lecture 17: Lecture 17 Disease and Population Dynamics
22 Dec 2018
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Indirect disease transmission: by touching surface that the infected individual physically touched: horizontal disease transmission: disease spread among individuals of the same generation, vertical disease transmission: transfer of disease from parent to offspring, evolution also acts on pathogens. It will sustain pathogens that are more adapted and likely to survive and reproduce: the fitness of a disease (measured as net reproductive rate): r0= bn/ (v+d+r) b= probability of infection. N= number of hosts available for infection by offspring. V= virulence (disease induced death rate of host) d= mortality (natural death rate of host) r= recovery of host. In horizontally transmitted disease the number of new hosts is proportional to the number of disease progeny. It doesn"t depend on the fitness of the host. In vertically transmitted disease the number of new hosts is dependent on host fitness. Immune: some individuals recover and become immune; now independent of the disease have per capita birth and death rates.
