International travel is now common worldwide for professional, social, recreational, and humanitarian purposes and has an increasingly

important impact on health care. Travelers are exposed to a variety of health risks in unfamiliar PI3 kinase pathway environments and fever is a common problem in patients returning from travel abroad.1 Fever is an important marker of potentially serious illness in returned travelers and a high percentage of the febrile returned travelers are categorized as having an unspecified febrile illness, meaning they did not have a confirmed or probable diagnosis.2,3 Malaria remained the most common diagnosis in febrile travelers who presented at GeoSentinel clinics from March 1997 through March 2006.2 Other causes of fever in returned travelers

include typhoidal and nontyphoidal salmonellosis, dengue fever, viral hepatitis, and rickettsial infections.2,3 Rickettsial infections in travelers are now of emerging importance as contact with the vectors, mainly ticks, but also fleas, is very common in several countries.2,3 Spotted fever group (SFG) rickettsiae are the second most common diagnosis for systemic febrile illness in travelers to sub-Saharan Africa.4 In the last 15 years African tick bite fever caused by Rickettsia africae has been described as the most frequent rickettsioses acquired by travelers in sub-Saharan Africa.5 Other SFG rickettsioses 5-Fluoracil ic50 such as Mediterranean spotted fever due to Rickettsia conorii have been reported as well as the flea-borne murine typhus caused by Rickettsia typhi, and scrub typhus caused by Orienta tsutsugamushi are transmitted by trombiculid mites. Recently, epidemiological aspects of rickettsial diseases were analyzed in 280 international travelers reported to the GeoSentinel

site from June 1996 through December 2008.6 82.5% of these cases were tick-borne rickettsioses, 5.7% were cases of scrub typhus, and 2.5% were cases of typhus group rickettsioses.6 Most cases were associated with travel to sub-Saharan Africa (75.1%). A European study by Bottieau and colleagues7 in 1,743 patients with fever identified that 4% of the febrile patients returning from Africa presented a rickettsial infection. Rickettsia conorii and R africae were identified in 53 patients, R typhi in four, and O tsutsugamushi Adenosine in three.7 Here we report three cases of murine typhus infection after travel in Tunisia and we review the available data about this disease in the Mediterranean area. The sera of patients returned from Tunisia were received at the WHO Collaborative Center for Rickettsioses and Other Arthropod-Borne Bacterial Diseases in Marseille. For each patient, an acute-phase serum sample was obtained within 2 weeks after the onset of symptoms and, when possible, a convalescent-phase serum sample (ie, one collected more than 2 wk after onset of symptoms) was also obtained.