Human Monocytic Ehrlichiosis Presenting as Altered Mental Status

1Somerset Medical Center, Somerville, NJ

Meeting: Hospital Medicine 2007, May 23-25, Dallas, Texas

Abstract number: 1000

Case Presentation:

A previously healthy 54‐year‐old man presented with a history of fever, sore throat, myalgias, worsening lethargy, diarrhea, and epistaxis. The patient had traveled to Mount Calazano, Italy, and England the month before admission and was an avid birdwatcher who frequently visited wooded areas. He was brought to the emergency room agitated and confused. On examination he was febrile, hypoxic, and hypotensive. His examination also revealed ecchymosis and nuchal rigidity. His laboratory data demonstrated neutropenia, thrombocytopenia, transaminitis, acute renal failure, diffuse ST elevation, and elevated CK, troponin I, and PT. The patient required immediate resuscitation and ventilator support. A diagnosis of human monocytic ehrlichiosis was considered, and therapy with doxycycline, vancomycin, and ceftriaxone was started. Despite aggressive measures, the patient died within 24 hours of admission. Premortem blood testing was positive for Ehrlichia chaffeensis (HME) IgG antibodies and positive for E. chaffeensis (HME) DNAby PCR. The blood was also positive for Anaplasma phagocytophilum (HGA) IgM antibodies. Testing was negative for Borrelia burgdorferi DNA by PCR and E. ewingii/canis DNA by PCR. Autopsy revealed myocarditis and endocarditis from ehrlichiosis caused by E. chaffeensis. Cardiac involvement was confirmed by PCR. The spleen and lymph nodes were also noted to test positive by PCR.


Ehrlichiae are obligate intracellular bacteria that grow in membrane‐bound vacuoles in human and animal leucocytes. The 2 most important human ehrlichial diseases are human monocytic ehrlichiosis, caused by Ehrlichia chaffeensis (HME), and human granulo‐cytic anaplasmosis, caused by A. phagocytophilum (HGA). HME and HGAare recognized as separate diseases. HME was first recognized in 1987, and more than 1500 cases have been recognized in the southeastern, south‐central, and mid‐Atlantic regions of the United States. Isolated cases have been reported in Europe, Africa, and Mexico. The reported annual incidence of HME in the United States is 0.7 cases per million population. Severe illness or death was more probable in patients who did not receive tetracycline or chloramphenicol until 8 days or more after the onset of symptoms (odds ratio, 4.38; 95% CI, 1.36‐14.0). The estimated mortality rate of HME is 2%‐5%.


Significant morbidity and mortality are associated with delayed treatment of HME. Hospitalists need to be aware of the early recognition of HME in patients presenting with unexplained febrile illness, rash, altered mental status, and multiorgan failure with a significant travel and recreational history, as noted in this case. Early recognition and empirical treatment with systemic tetracycline are highly warranted.

Author Disclosure Block:

A. Devarajan, None.

To cite this abstract:

Devarajan A. Human Monocytic Ehrlichiosis Presenting as Altered Mental Status. Abstract published at Hospital Medicine 2007, May 23-25, Dallas, Texas Abstract 1000. Journal of Hospital Medicine. 2007; 2 (suppl 2). Accessed April 10, 2020.

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