Prevalence of antibodies against spotted fever group rickettsiae in a rural area of Colombia.

We recently rediscovered Rocky Mountain spotted fever in Villeta, Colombia, near the same locality (Tobia) where it was first recognized in 1937. To have a better idea of the magnitude of this problem, sera from 392 randomly recruited healthy adults from Villeta were analyzed by indirect immunofluorescent antibody assay to detect IgG against Rickettsia rickettsii as antigen. The seropositivity rate for spotted fever group rickettsiae was 40.3%. We did not find any association between the presence of antibodies to spotted fever group rickettsiae and several demographic and epidemiologic variables, which could be a reflection of unique features of this area.