There are other contagious illnesses that spread to small communities, such as chronic diseases like leprosy and yaws. Because the disease takes a very long time to kill the sick person so the person still lives as a germ repository that infects other tribal members. Cats She Lived Happily Ever After poster. For example, in the Karimui Basim region of the New Guinea highlands where I worked in the 1960s, there was an isolated community of only a few thousand people, the group with the highest incidence of leprosy in the world – about 40%! Finally, few communities are more susceptible to non-fatal communicable diseases for which we are not immune, as a result, the same person may become infected again after recovery. That is the case of filariasis and many other parasitic diseases.