A study on tick-borne rickettsiosis was developed in the county of Santa
Cruz do Escalvado, State 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 to Anocentor nitens.
The hemolymph test associated with Gimenez staining showed that 18 of the
221 A. cajennense specimens, 1 of the 16 R. sanguineus, 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 was the only species found
on humans.
