The article “Diagnosis of Lyme Disease” (July 15, 2005, page 297) contained an error in the first paragraph in the left column of page 298. The first sentence of this paragraph incorrectly listed the causative pathogen of human granulocytic ehrlichiosis as Babesia microti. The sentence should have read as follows: “Ten percent of patients also have another tick-borne illness, such as human granulocytic ehrlichiosis (caused by a rickettsial-like pathogen) or babesiosis (caused by Babesia microti). The online version of this article has been corrected.