Human ehrlichioses in Brazil: first suspect cases.

Brazilian spotted fever (BSF) rickettsiosis is the most common and recognized of the human rickettsioses in Brazil. It is difficult to establish the diagnosis of human rickettsiosis infection by routine microbiologic methods, creating a false idea that Rickettsia and Ehrlichia infections are rare and without importance. New tick-borne diseases, like human granulocytic anaplasmosis (HGA) and human monocytic ehrlichiosis (HME), have been described in many countries. These diseases can present symptoms similar to rickettsioses of the spotted fever group, and they are transmitted by ixodid ticks. The first two suspected cases of human ehrlichiosis in Brazil were first considered to be cases of BSF. The differential diagnosis was made at the Minas Gerais Rickettsiosis Public Health Laboratory. The clinical and laboratory findings, with positive serology for the HME agent, indicated suspected cases of human ehrlichioses in Brazil.