Boutonneuse Fever and African Tick-bite Fever

Boutonneuse Fever and African Tick-bite Fever

Boutonneuse fever and its agent were first described in North Africa in 1910, and variants of R. conorii have been identified in South Africa, Kenya, Somalia, Israel, Morocco, Ethiopia, Russia, India and Pakistan. In parts of Africa, tick-transmitted diseases caused by R. conorii and R. africae overlap geographically. Although their clinical manifestations also overlap, there are differences sufficient to distinguish two different disease agents. Generally milder than boutonneuse fever, African tick bite fever has a lower incidence of rash, which is more often vesicular and sparse, a higher incidence of eschars that are frequently multiple, and more prominent regional lymphadenopathy. Each of these diseases has been diagnosed in the United States after patients return from vacation abroad, particularly from African safaris.