Ehrlichia chaffeensis

Introduction

Small obligate, intracellular coccobacillus that infects monocytes.

Epidemiology

• reservoir of Ehrlichia chaffeensis are deer, dogs & goats
• vectors of Ehrlichia chaffeensis are ticks:
  • Amblyomma americanum (Lone Star tick)
• Ehrlichia chaffeensis is endemic in the same areas where Rickettsia rickettsii (etiologic agent of Rocky Mountain spotted fever) is found.

Pathology

• infects monocytes
• etiologic agent of ehrlichiosis

Laboratory

• Ehrlichia chaffeensis antigen
• Ehrlichia chaffeensis serology
• Ehrlichia identified by light microscopy
  • staining of peripheral blood neutrophils & monocytes for morula or loose aggregrates of bacteria within monocytes
• Ehrlichia chaffeensis DNA
  • Ehrlichia chaffeensis groEL gene

More general terms

• Ehrlichia

Additional terms

• ehrlichiosis