Tick-borne rickettsioses in international travellers

Abstract

Background: Tick-borne rickettsioses are of emerging importance in today's travel medicine but have until recently received little attention. We describe the current knowledge of tick-borne rickettsioses as they relate to international travel, their microbiological diagnosis, treatment, possible prevention, and future prospects.

Methods: Literature-based review and personal observations.

Results: During the last decade, some 400 cases of tick-borne rickettsioses have been reported in international travellers, the vast majority being African tick bite fever caused by Rickettsia africae and Mediterranean spotted fever caused by Rickettsia conorii. Only a minority of infected travellers can recall a preceding tick bite. Most patients present with a mild-to-moderately severe flu-like illness typically accompanied by a cutaneous rash and an inoculation eschar at the site of the tick bite, but potentially life-threatening disease with disseminated vaculitis is occasionally seen. Definite microbiological confirmation of tick-borne rickettsioses by isolation or antigen detection is only available at reference laboratories and diagnosis must in most cases rely on clinical and epidemiological data supported by serology. Doxycycline is the recommended treatment for tick-borne rickettsioses and prevention is based on personal protective measures against tick bites when travelling in endemic areas.

Conclusion: Tick-borne rickettsiosis should be suspected in febrile returnees from endemic areas, especially in cases with skin eruptions. Travellers to endemic areas should be encouraged to use personal protective measures against tick bites.