Imported rickettsioses in Italy

Background: In Italy few cases of rickettsioses have been reported in travellers and autochthonous cases are attributed predominantly to Rickettsia conorii, the agent of Mediterranean spotted fever.

Method: The purpose of this study was to investigate some epidemiological and clinical features of tick-borne spotted fever group rickettsiosis acquired abroad or in Italy. Serum specimens collected prospectively from patients with suspected rickettsioses were tested by immunofluorescence assay. A definitive diagnosis was made on the basis of positive serological test results at the WHO collaborative centre for rickettsial diseases, Marseille, France. We compared the clinical features of patients with confirmed rickettsioses and those showing typical clinical symptoms/signs without definitive diagnose.

Results: Eight of 26 patients suspected cases had confirmed rickettsioses. All patients were travellers returning from southern Africa (75% Rickettsia africae). Inoculation eschars were significantly more common in patients with confirmed rickettsioses (p = 0.004).

Conclusions: Our study demonstrates that R. africae is the most frequent rickettsia observed in Italian travellers. Prior to receiving the laboratory results, physicians should start empirical treatment on the basis of epidemiologic data (e.g., travel history to Africa), and clinical findings compatible with rickettsioses (e.g., eschars).