RICKETTSIAE-INFECTED TICKS IN AN ENDEMIC AREA OF SPOTTED-FEVER IN THESTATE OF MINAS-GERAIS, BRAZIL

A study on tick-borne rickettsiosis was developed in the county of San ta Cruz do Escalvado, Stare of Minas Gerais, Brazil, where a clinical case of the disease confirmed by necropsy, had been reported. Of the 1 ,254 ticks collected, 1,061 belonged to the Amblyomma genus, 57 to the Rhipicephalus sanguineus species, 81 to Boophilus microplus, and 46 t o Anocentor nitens. The hemolymph test associated with Gimenez stainin g showed that 18 of the 221 A. cajennense specimens, 1 of the 16 R. sa nguineus, 1 of the 22 B. microplus, 3 of the A. nitens, and 1 of the A . ovale contained rickettsia-like microorganisms. Only 3 A. cajennense ticks were positive under direct immunofluorescence. A. cajennense wa s the only species found on humans.