(Duh.)
http://www.nature.com/news/gut-microbial-enterotypes-become-less-clear-cut-1.10276

GENERAL
highly contagious ectoparasitic skin infection
mite: Sarcoptes scabii
makes superficial burrows in epidermis entering via hair follicles, lays eggs, has babies
worse in immunocompromised, malnourished, elderly or institutionalized individuals
Wikipedia says the Norwegian strain is worst (???)
no vaccine available
( notes )

New science indicates that Chagas infection in humans is at least 4500 years old if not 9000, and that infection occurred before domicilization of triatomine insects. Two types of T. cruzi display distinct characteristics and may one type appears to be transmitted orally, resulting in severe disease in children.
( notes from a letter to the editor by several Brazilian docs of the Oswaldo Cruz Foundation in Rio de Janeiro )