Ehrlichiosis

From Anvita Health Wiki

Contents 1 Etiology 2 Epidemiology 3 Clinical-manifestations 4 Laboratory 5 Management 6 More General Terms 7 Additional Terms 8 References

Etiology

• infection by Ehrlichia chaffeensis

Epidemiology

• infection transmitted by tick 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

Clinical-manifestations

• similiar to anaplasmosis
• fever
• headache
• myalgias
• maculopapular skin eruption (40%)

• spares extremities, palms, soles
• distinguishing feature from Rocky Mountain spotted fever is central distribution with peripheral sparing
• petechiae

Laboratory

• abnormal liver function tests
• complete blood count ( CBC)

• leukopenia
• thrombocytopenia

• microscopic examination of peripheral blood

• generally will NOT show organism
• staining of peripheral blood neutrophils & monocytes for morula or intracytoplasmic loose aggregrates of bacteria within monocytes (E. chaffeensis) or granulocytes (E. phagocytophilia & E. equi) is diagnostic

• serology: acute & convalescent sera

• standard method
• may be negative early in disease
• NOT useful for evaluating clearance of organism

• polymerase chain reaction ( PCR)

Management

• doxycycline PO or IV

• empiric treatment in patient with suspected disease
• response to treatment my occur in 1-3 days
• continue treatment for several days after patient has become afebrile

• rifampin may be alternative in pregnant women [1]

More General Terms

• tick borne infection
• Rickettsia infection

Additional Terms

• Ehrlichia

References

1. Medical Knowledge Self Assessment Program (MKSAP) 11, 14, American College of Physicians, Philadelphia 1998, 2006
2. Harrison's Principles of Internal Medicine, 14th ed. Fauci et al (eds), McGraw-Hill Inc. NY, 1998, pg 91

ehrlichiosis