ehrlichiosis

noun

ehr·lich·i·o·sis er-ˌli-kē-ˈō-sis

plural ehrlichioses er-ˌli-kē-ˈō-ˌsēz

: infection with or a disease caused by tick-borne bacteria (genus Ehrlichia of the family Anaplasmataceae) that in humans is marked especially by fever, headache, chills, muscle aches, and fatigue

Note: Following taxonomic reclassification of the causative agent (Ehrlichia phagocytophila) of the granulocytic form of human ehrlichiosis as an anaplasma (Anaplasma phagocytophilum), the disease is now referred to as either human granulocytic ehrlichiosis, human granulocytic anaplasmosis, or simply, anaplasmosis.

Example Sentences

Recent Examples on the Web Lone star ticks, abundant in the South, transmit infections like tularemia, ehrlichiosis, and a Lyme-like illness not yet identified. —

Linda Marsa, Discover Magazine, 4 Feb. 2011 Where the deer go, so do their parasites, and these include the lone star tick, the animal that spreads ehrlichiosis. —

Ed Yong, Discover Magazine, 12 Oct. 2010 These pests can transmit a number of serious diseases to your dog, including Lyme disease, Rocky Mountain spotted fever, and ehrlichiosis. —

Amber Smith, Discover Magazine, 18 Oct. 2022 In 1999, the Centers for Disease Control and Prevention recorded just 100 or so cases of ehrlichiosis in the United States. —

Ed Yong, Discover Magazine, 12 Oct. 2010 According to the American Kennel Club’s Canine Health Foundation, ticks can carry diseases such as ehrlichiosis, Rocky Mountain spotted fever and Lyme disease. —

Jacob Livesay, USA TODAY, 7 Aug. 2022 Rickettsial illnesses include ehrlichiosis (15%), Rocky Mountain spotted fever (6%) and anaplasmosis (5%). —

Paul A. Smith, Milwaukee Journal Sentinel, 7 May 2022 In Wisconsin ticks can spread Lyme disease, anaplasmosis, babesiosis, Borrelia miyamotoi, ehrlichiosis, Powassan virus, Rocky Mountain spotted fever and tularemia. —

Paul A. Smith, Milwaukee Journal Sentinel, 7 May 2022 Another disease spread by the lone star tick is ehrlichiosis, which has flu-like symptoms including headache, joint and muscle ache, fever, and fatigue. —

Kevin Ambrose, Anchorage Daily News, 2 May 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'ehrlichiosis.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History

Etymology

New Latin, from Ehrlichia, bacteria genus, from Paul Ehrlich

First Known Use

1965, in the meaning defined above

Time Traveler

The first known use of ehrlichiosis was in 1965

See more words from the same year

Cite this Entry

Style

“Ehrlichiosis.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ehrlichiosis. Accessed 27 Mar. 2023.

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Medical Definition

ehrlichiosis

noun

ehr·lich·i·o·sis er-ˌlik-ē-ˈō-sis

plural ehrlichioses -ˌsēz

: infection with or a disease caused by tick-borne bacteria of the genus Ehrlichia that affects both humans and animals (such as dogs, horses, and sheep) and that in humans is marked especially by fever, headache, chills, muscle aches, and fatigue

Note: When ehrlichiosis occurs in humans, the disease is often referred to as human granulocytic ehrlichiosis or human monocytic ehrlichiosis depending on the type of white blood cell (granulocyte or monocyte) infected. Following reclassification of the causative agent of human granulocytic ehrlichiosis to the genus Anaplasma, human granulocytic ehrlichiosis is now also called human granulocytic anaplasmosis or simply, anaplasmosis.