relapsing fever


: a variable acute epidemic disease that is marked by recurring high fever usually lasting three to seven days and is caused by a spirochete (genus Borrelia) transmitted by the bites of lice and ticks

Examples of relapsing fever in a Sentence

Recent Examples on the Web Tick bites can transmit Rocky Mountain spotted fever and tick-borne relapsing fever. Tiffany Acosta, The Arizona Republic, 18 June 2024 This wasn’t a total shock, as B. lonestari is a close relative of B. miyamotoi, which is known to cause tickborne relapsing fever. Sarah Kuta, Smithsonian Magazine, 13 Mar. 2023 This led to their official diagnosis of tickborne relapsing fever caused by the bacteria. Sarah Kuta, Smithsonian Magazine, 13 Mar. 2023 New research suggests the bacteria infected the 75-year-old man with tickborne relapsing fever, an uncommon condition that causes nausea, recurring fever, headaches and muscle and joint aches. Sarah Kuta, Smithsonian Magazine, 13 Mar. 2023 Thus, the relapsing fever can be spread by the bite of larval ticks as well as the customary nymphs that cause Lyme. Wendy Orent, Discover Magazine, 11 Dec. 2013

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'relapsing fever.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1828, in the meaning defined above

Time Traveler
The first known use of relapsing fever was in 1828

Dictionary Entries Near relapsing fever

Cite this Entry

“Relapsing fever.” Dictionary, Merriam-Webster, Accessed 15 Jul. 2024.

Medical Definition

relapsing fever

: a variable acute infectious disease that is marked by sudden recurring episodes of high fever which usually last from three to seven days, are typically accompanied by myalgia, arthralgia, headache, nausea, and chills, and often end in a crisis stage marked by a spike in fever followed by an afebrile period and that is caused by a spirochete of the genus Borrelia (as B. hermsii, B. parkerii, or B. recurrentis) that circulates in the blood and is transmitted by the bite of a body louse (Pediculus humanus humanus) or a tick of the genus Ornithodoros see mianeh fever

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