Epidemiology of boutonneuse fever in western Sicily. Distribution and prevalence of spotted fever group rickettsial infection in dog ticks (Rhipicephalus sanguineus

neuse fever in western Sicily: distribution and prevalence of spotted fever group rtckettsial infection in dog ticks (Rhipicephalus sangulneua). Am J Epidemiol 1986;123:721-7. The distribution and prevalence of spotted fever group rickettsial infection in the ixodfd dog tick Rhlplcophahts aangulneus were found to occur at a rate of 19.7 % with variation related to geographic and soctooccupational factors. A higher rate of infection was demonstrated in ticks removed from dogs associated with documented cases of boutonneuse fever. The results fit into available clinical and seroepklemtologic data on Rlckettsla conorll infection in western Sicily. rickettsiaceae infections; ticks Rickettsia conorii belongs to the spotted fever group of rickettsiae and is the agent of boutonneuse fever, an exanthematic dis-ease which is widespread in the Eastern Hemisphere. Boutonneuse fever occurs during the summer months and is mild in the great majority of cases; on occasion, it may be more severe, and in few cases, com-plications also occur, mainly in debilitated persons (1-3). The chief vector, Rhipi-cephcdus sanguineus, is also the main res-ervoir, since the infection is transmitted by the transovarial route. Recently, there has been a sharp increase in the incidence of Received for publication March 19, 1985, and in final form August 12, 1985.