Bacterial pathogens

  Imagine two bacterial pathogens, A and B. A is spread by the fecal-oral route and causes severe diarrheal disease. B causes a sexually-transmitted disease. Using your knowledge of the evolutionary mechanisms discussed in Perlman’s book (chapter 7&8) “Evolution & Medicine” by Robert L. Perlman, answer the following four questions. 1) How might determining the basic reproductive number (brn) differ for A and B? In other words, what variables would be critical for calculating and interpreting the brn for A and for B? 2) What would be the expected initial direction of change in virulence due to selection on A versus selection on B given their modes of transmission, and why? 3) What societal conditions might would favor or discourage transmission of A as opposed to transmission of B? Cite two or three such conditions and contrast the effects, if any, on transmission for A vs. B. 4) What cultural practices would favor or discourage transmission of A versus transmission of B? Cite two or three such practices and contrast the effects, if any, on transmission for A vs. B.