Why don vectors contract the disease they carry?
Well, the vectors do contract the disease, some human diseases seem to not affect the vector and others will affect the vector especially behavorally (look at rabies). But usually the vector is an insect and the the reason it doesn’t affect the life of the vector is understadable. In short, if the disease killed or greatly harmed the main source of distribution it would die out quickly, by leaving the vector relatively unharmed the disease itself has a greater chance to be spread and to reproduce in acceptable areas. The selective pressures involved with high reproduction rates will surely favor those diseases that keep their hosts alive to spread, it can reproduce high amounts inside the human but does not need to in the mosquito and it would make the reproduction of the disease and range of the vector significantly lower. more specific.. When the bacteria or virus is in the vector it is at a different time of the bacteria/virus’ lifecycle that allows the vector to live a somewhat nor
