Ehrlichiosis ewingii infection[1] is an infectious disease caused by an intracellular bacteria, Ehrlichia ewingii.[2] The infection is transmitted to humans by the tick, Amblyomma americanum. This tick can also transmit Ehrlichia chaffeensis, the bacteria that causes human monocytic ehrlichiosis (HME).
| Human ewingii ehrlichiosis | |
|---|---|
| Specialty | Infectious disease |
Symptoms and signs
editPatients can present with fever, headache, myalgias, and malaise. Laboratory tests may reveal thrombocytopenia, leukopenia, and evidence of liver damage.[citation needed]
Mechanism
editHumans contract the disease after a bite by an infected tick of the species Amblyomma americanum.[citation needed] Those with an underlying immunodeficiency (such as HIV) appear to be at greater risk of contracting the disease. Compared to HME, ewingii ehrlichiosis has a decreased incidence of complications.[3]
Like Anaplasma phagocytophilum, the causative agent of human granulocytic ehrlichiosis, Ehrlichia ewingii infects neutrophils. Infection with E. ewingii may delay neutrophil apoptosis.[4]
Diagnosis
editIn endemic areas, a high index of suspicion is warranted, especially with a known exposure to ticks. The diagnosis can be confirmed by using PCR.[5] A peripheral blood smear can also be examined for intracytoplasmic inclusions called morulae.[citation needed]
Treatment
editThe treatment of choice is doxycycline.[citation needed]
See also
editReferences
edit- ^ Rapini, Ronald P., Bolognia, Jean L., Jorizzo, Joseph L. (2007). Dermatology: 2-Volume Set. St. Louis: Mosby. p. 1130. ISBN 978-1-4160-2999-1.
- ^ Patnaik MM (June 2009). "Inclusion bodies in tick-borne diseases diagnosed in patients from northern Wisconsin". Clin Med Res. 7 (1–2): 45–7. doi:10.3121/cmr.2009.807.818. PMC 2705270. PMID 19574488.
- ^ Paddock CD, Folk SM, Shore GM, et al. (November 2001). "Infections with Ehrlichia chaffeensis and Ehrlichia ewingii in persons coinfected with human immunodeficiency virus". Clinical Infectious Diseases. 33 (9): 1586–94. doi:10.1086/323981. PMID 11568857.
- ^ Xiong Q, Bao W, Ge Y, Rikihisa Y (April 2008). "Ehrlichia ewingii infection delays spontaneous neutrophil apoptosis through stabilization of mitochondria". The Journal of Infectious Diseases. 197 (8): 1110–8. doi:10.1086/533457. PMID 18462160.
- ^ Gusa, Aa, Buller, Rs, Storch, Ga, Huycke, Mm, MacHado, Lj, Slater, Ln, Stockham, Sl, Massung, Rf (Nov 2001). "Identification of a p28 gene in Ehrlichia ewingii: evaluation of gene for use as a target for a species-specific PCR diagnostic assay". Journal of Clinical Microbiology. 39 (11): 3871–6. doi:10.1128/JCM.39.11.3871-3876.2001. PMC 88457. PMID 11682500.