Primary Isolation of Ehrlichia chaffeensis from Patients with Febrile Illnesses: Clinical and Molecular Characteristics

Authors

Steven M. Standaert
Tina Yu
Margie A. Scott
James E. Childs, Centers for Disease Control and Prevention, AtlantaFollow
Christopher D. Paddock
William L. Nicholson
Joseph Singleton Jr.
Martin J. Blaser

Document Type

Article

Date of this Version

2000

Comments

Published in The Journal of Infectious Diseases 2000; 181:1082-8

Abstract

Ehrlichia chaffeensis was sought among patients with a history of tick exposure and fever, and the accuracy of other diagnostic tests was compared with that of primary isolation. Among the 38 patients enrolled, E. chaffeensis was isolated from the blood of 7 (18%) and from cerebrospinal fluid specimens of 2 of these 7. All 7 patients also were positive by polymerase chain reaction (PCR) of blood, and 6 patients developed diagnostic titers of antibody to E. chaffeensis. The isolates were characterized by molecular analysis of the 16S rRNA gene, the 120-kDa protein gene, and the variable-length PCR target (VLPT) of E. chaffeensis. On the basis of the 120-kDa and VLPT genotypes, the cerebrospinal fluid and blood isolates from the same patients were identical. This study demonstrates that both PCR and culture of blood for E. chaffeensis have high diagnostic yields. More frequent isolation of E. chaffeensis from patients with infection should further our understanding of the pathogenesis of this infection.