Rickettsiae and rickettsial diseases in Croatia: Implications for travel medicine

SummaryAimTo review the current state of knowledge concerning rickettsiae and rickettsioses in Croatia and to discuss their implications for travellers.MethodsThe PubMed database was searched from 1991 to 2015 by combining the words “rickettsia,” “rickettsiosis”, “travellers” and “Croatia”.ResultsSince 1969, Croatia appears to be free of epidemic typhus (ET) caused by Rickettsia prowazekii and the last case of Brill-Zinsser disease was recorded in 2008.Mediterranean spotted fever (MSF) caused by Rickettsia conorii is the most frequent human rickettsial infection in Croatia, followed by murine typhus caused by Rickettsia typhi. Human cases of MSF and murine typhus have been predominantly observed along the eastern Adriatic coast from Zadar to Dubrovnik and between Zadar and Split, respectively.Rickettsia akari, etiologic agent of rickettsialpox, was isolated from blood of a patient diagnosed with MSF in Zadar, but no cases of rickettsialpox were reported.Several species of pathogenic (Rickettsia slovaca, Rickettsia aeschlimannii, Ricketsia helvetica, and Ricketsia raoultii) and species of undetermined pathogenicity (Ricketsia hoogstraalii sp. nov.) rickettsiae were identified in ticks collected in different ecological regions of Croatia.A search of the literature revealed no evidence of rickettsial infection in travellers visiting Croatia. Three imported cases of Rickettsia africae were observed in travellers returning from South Africa.ConclusionRickettsiae and rickettsial diseases continue to be present in Croatia. As they can be acquired while travelling, physicians should consider rickettsial infection in the differential diagnosis of patients returning from Croatia and presenting with febrile illness.