The American Society for Rickettsiology was organized in 1979 to foster exchange of information among American scientists engaged in research on Rickettsiae and Rickettsial diseases. Currently, about 200 scientists and students are members of this organization and meetings are held every eighteen months. The field encompasses a wide range of human pathogens and includes members of the genera Anaplasma, Bartonella, Coxiella, Ehrlichia, Orientia and Rickettsia.