Possible Typhoon-related melioidosis epidemic, Taiwan, 2005.

sequencing. This infection rate is within the range (13.5%–90%) that has been reported for R. felis infecting Ctenocephalides fl eas in Brazil and Uruguay (2,3,7). Sixteen (72.7%) cats contained R. felis–reactive antibodies; 4 of them showed titers to R. felis at least 4-fold higher than those to the other 5 rickettsial strains, fi ndings that enabled us to technically conclude that these cats were exposed to R. felis or a closely related organism (1,7,9). Our fi nding of 70% R. felis infection in fl eas infesting the cats indicates that cats acquired the infection through infected fl eas. However, the mechanism of R. felis transmission by fl eas is yet to be demonstrated under experimental conditions. To our knowledge, the presence of R. felis, or a spotted fever group Rickettsia species, has not been reported in Chile. Recent investigations have provided clinical and serologic evidence of canine (10) and human (K. Abarca and J. Lopez, unpub. data) infection by spotted fever rickettsia in Chile, confi rmed by IFA that used R. conorii commercial antigen. Since substantial serologic cross-reaction occurs between R. conorii and R. felis antigens (1), R. felis could be causing infection in dogs or humans in Chile.