Rickettsia IgG antibody testing is a serological test detecting IgG antibodies specific to Rickettsia bacterial antigen. Rickettsia are bacteria causing Rocky Mountain spotted fever, typhus and rickettsial pox. IgG antibodies produced by the immune system determine long-term infection and remain detectable in blood for an extended period after the initial exposure. The test helps diagnose past exposure to rickettsia and guide treatment decisions.