Detection of a rickettsia closely related to Rickettsia aeschlimannii, "Rickettsia heilongjiangensis," Rickettsia sp. strain RpA4, and Ehrlichia muris in ticks collected in Russia and Kazakhstan.

Using PCR, we screened 411 ticks from four genera collected in Russia and Kazakhstan for the presence of rickettsiae and ehrlichiae. In Russia, we detected "Rickettsia heilongjiangensis," Rickettsia sp. strain RpA4, and Ehrlichia muris. In Kazakhstan, we detected Rickettsia sp. strain RpA4 and a rickettsia closely related to Rickettsia aeschlimannii. These agents should be considered in a differential diagnosis of tick-borne infections in these areas.