Ehrlichiosis and anaplasmosis

Human monocytotropic/monocytic ehrlichiosis (HME) and human granulocytotropic/granulocytic anaplasmosis (HGA) are acute infections that either resolve completely or lead to complications including death. Case-fatality rates in the US are approximately 0.3% for HGA and 1% (4% in children <5 years of age) for HME. No deaths from human ewingii ehrlichiosis (HEE) were reported between 2008 and 2012.[15]Nichols Heitman K, Dahlgren FS, Drexler NA, et al. Increasing incidence of Ehrlichiosis in the United States: a summary of national surveillance of Ehrlichia chaffeensis and Ehrlichia ewingii infections in the United States, 2008-2012. Am J Trop Med Hyg. 2016 Jan;94(1):52-60. http://www.ncbi.nlm.nih.gov/pubmed/26621561?tool=bestpractice.com ​[23]Dahlgren FS, Heitman KN, Drexler NA, et al. Human granulocytic anaplasmosis in the United States from 2008 to 2012: a summary of national surveillance data. Am J Trop Med Hyg. 2015 Jul;93(1):66-72. http://www.ncbi.nlm.nih.gov/pubmed/25870428?tool=bestpractice.com ​​ HME is more severe and lethal in patients with HIV/AIDS or other immunosuppressive conditions. More severe disease and complications are observed in patients over 60 years of age. Once treated successfully, human ehrlichioses do not relapse or recur unless the patient is bitten by a tick again. Even though chronic progression has been reported in zoonotic hosts, chronicity has not been described in humans to date.