Ehrlichiosis

Ehrlichiosis or anaplasmosis is anthropozoonosis caused by obligatory intracellular bacteria and transmitted by ticks.


 * it is a newly diagnosed disease - previously thought to be infectious to dogs only
 * may resemble some forms of Lyme borreliosis
 * occurs very rarely in the Czech Republic

Etiology

 * gram-negative bacteria of the genus  Ehrlichia, in our country  Anaplasma  (formerly Ehrlichia)  phagocytophila 
 * transmission tick (genus Ixodes, Amblyoma, Dermacentor)
 * the morphology of bacteria is variable, usually cocci or cocobacillus
 * Echaff.jpg located inside leukocytes in membrane-bounded vacuoles, forming intracytoplasmic vacuolar microcolonies called "morulas"

Pathogenesis
Bacteria penetrate:


 * 1) granulocytes - the so-called  human granulocyte ehrlichiosis / anaplasmosis - HGE, IGA  - originates of the Anaplasma phagocytophilum, transmitted by ticks of the genus Ixodes, the reservoir is small mammals, wild animals and horses; co-infection possible Borrelia burgdorferi 
 * 2) monocytes - human monocytic ehrlichiosis / anaplasmosis is formed - HME, IME  - causative agent E. chaffeensis, transmitted by ticks of the genera Amblyoma and Dermacentor, the reservoir is dogs and wild animals

Clinical picture

 * diverse and non-specific:
 * headache, fatigue, muscle pain, fever, dyspepsia, cough, nausea, (maculopapular rash is present in monocytic ehrlichiosis)
 * internal organ involvement - most often lungs, liver, CNS.

Diagnostics

 * indirect - detection of antibodies by immunofluorescence test (IFA)
 * direct - PCR
 * in blood count: leukopenia (especially neutropenia), thrombocytopenia, sometimes anemia
 * elevated liver tests

Therapy

 * broad-spectrum antibiotics - doxycycline, tetracycline, chloramphenicol