Outbreak of African Tick-Bite Fever in Six Italian Tourists Returning from South Africa

Abstract

In May 1999, a cluster of cases of African tick-bite fever was detected in six Italian tourists who had returned from South Africa. All of the patients had moderate fever and cutaneous eschars. Regional lymphangitis was observed in three of the patients and skin rash in two. By comparing the number of eschars with the number of detectable bite sites it was suggested that at least two-thirds of the biting vectors were capable of transmitting Rickettsia africae. The clinical course of disease was mild in all cases, and all but one of the patients recovered spontaneously before antibiotic treatment was initiated. The diagnosis of African tick-bite fever was confirmed serologically using both microimmunofluorescence and Western blot tests.

Tick-Borne Rickettsioses around the World: Emerging Diseases Challenging Old Concepts

“…Risk areas include wildlife attractions in natural parks, where the tick vectors are highly prevalent and attack readily any person who enters their biotope. Up to 74% of travelassociated cases of African tick bite fever occur in clusters (62,110). The incubation period ranges from 5 to 7 days, up to 10 (145).…”

Tick-borne rickettsioses in international travellers

“…For instance, during the investigation of an outbreak of African tick bite fever among Italian safari tourists to South Africa, as many as 53 tick bites, of which 34 subsequently developed into inoculation eschars, were documented in five patients. 18 Other important features of African tick bite fever include prominent neck muscle myalgia, headache, regional lymphadenitis, and, less frequently, a vesicular cutaneous rash and aphthous stomatitis. 19,20 The clinical course is frequently mild, but may be complicated by reactive arthritis and prolonged fever.…”

“…Since then, more than 350 travel-associated cases have been reported from Europe, North America, Australia, Argentina, and Japan. 3,7,[17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] Most cases are infected in South Africa, where many popular wildlife attractions are highly endemic for R. africae infection 37 and where the abolition of apartheid in the early 1990s was followed by an unprecedented rise in international safari tourism. African tick bite fever has been reported in a wide spectrum of travellers, including leisure safari tourists, foreign aid workers, film crew members, game hunters, students, sports competitors, and deployed soldiers.…”

Rickettsiosis as Threat for the Traveller

“…ATBF and MSF are the most frequent tick-borne spotted fever rickettsioses in travellers (Smoak et al, 1996;Fournier et al, 1998;Oteo et al, 2004a;Raoult et al, 2001;Caruso et al, 2002;Jensenius et al, 2003;Roch et al, 2008;Tsai et al, 2008;Consigny et al, 2009;Stephany et al, 2009;Althaus et al, 2010;Jensenius et al, 2004;Boillat et al, 2008;Laurent et al, 2009). For this reason, we will refer to these conditions taking into account that few differences in the incubation period and severity may exist.…”