| rickettsial infection in animals, humans and ticks in paulicéia, brazil. | a previous study in paulicéia municipality, south-eastern brazil, reported 9.7% of the amblyomma triste ticks to be infected by rickettsia parkeri, a bacterial pathogen that causes spotted fever in humans. these a. triste ticks were shown to be associated with marsh areas, where the marsh deer blastocerus dichotomus is a primary host for this tick species. during 2008-2009, blood serum samples were collected from 140 horses, 41 dogs, 5 opossums (didelphis albiventris) and 26 humans in farms from ... | 2015 | 25643912 |