The Gulf Coast Tick (Amblyomma maculatum) is a Nearctic and Neotropical hard tick found in coastal areas of the southern United States, with inland range extensions in Kansas, Oklahoma, and some other states. It is also found in parts of several Central and South American countries that border the Gulf of Mexico and Caribbean Sea, including Mexico, Guatemala, Belize, Nicaragua, Honduras, Costa Rica, Colombia, Venezuela, and some parts of Ecuador and Peru. (Sumner et al. 2007 and references therein) Larvae and nymphs feed on small rodents and ground-swelling birds. Adults primarily feed on the ears of large mammals and are considered an economic pest of cattle. (H.R. Williams et al., Texas A&M Tick Research Laboratory)
Rickettsia parkeri, a member of the spotted fever group rickettsiae, was initially identified in Gulf Coast ticks in 1937. In 2004, the first confirmed human infection with R. parkeri was reported. Since that report, confirmed cases of R. parkeri rickettsiosis have been identified in other persons in Mississippi, Virginia, and possibly other U.S. states. Investigations by Sumner et al. (2007) detected R. parkeri in ticks from Florida, Georgia, Kentucky, Mississippi, Oklahoma, and South Carolina, suggesting that A. maculatum may be responsible for additional cases of R. parkeri rickettsiosis throughout much of its U.S. range. It appears that in the United States R. parkeri can be found anywhere that A. maculatum ticks are found. Another Amblyomma species, A. triste, has been implicated as a likely vector of R. parkeri in Uruguay (Sumner et al. 2007 and references therein)
