chlamydia

noun

chla·​myd·​ia klə-ˈmi-dē-ə 

plural chlamydiae klə-ˈmi-dē-ˌē 

1

: any of a genus (Chlamydia, family Chlamydiaceae) of spherical gram-negative intracellular bacteria

especially : one (C. trachomatis) that causes or is associated with various diseases of the eye and urogenital tract including trachoma, lymphogranuloma venereum, cervicitis, and some forms of urethritis

2

: a disease or infection caused by chlamydiae

chlamydial

klə-ˈmi-dē-əl 

adjective

Examples of chlamydia in a Sentence

Recent Examples on the Web

Cases of the most common STD, chlamydia, remained the same in 2022 with 1.6 million cases amounting to 495 cases per 100,000 persons – similar to the rate in 2021 of 495.5 per 100,000 in 2021. —Mike Snider, USA TODAY, 25 June 2024

While effects against gonorrhea may be limited, and further interventions such as vaccines may be indicated, the prophylaxis has a chance of controlling the spread of chlamydia and syphilis, said Connie Celum, a professor of global health, medicine, and epidemiology at the University of Washington. —Annalisa Merelli, STAT, 4 June 2024

Data from the Centers for Disease Control and Prevention shows that among those 65 and older, chlamydia diagnoses more than tripled between 2010 and 2023. —Leana S. Wen, Washington Post, 18 June 2024

Some of the most common causes include chlamydia and gonorrhea. —Dr. Roshini Raj, Health, 17 June 2024

Word History

Etymology

borrowed from New Latin, originally the name of a group, from Greek chlamyd-, chlamýs "mantle, chlamys" + New Latin -ia -ia entry 1

Note: The taxon Chlamydia was originally assigned to a group of microorganisms neither bacterial nor viral by Helen Jones, Geoffrey Rake, and Barbara Stearns in "Studies on lymphogranuloma venereum III. The action of the sulfonamides on the agent of lymphogranuloma venereum," Journal of Infectious Diseases, vol. 76, issue 1 (January, 1945), pp. 55-69. The choice of the element chlamyd- was presumably based on the earlier taxon Chlamydozoa (with -zoa -zoa) originated by Ludwig Halberstädter and Stanislaus von Prowazek, "Über Zelleinschlüsse parasitärer Natur beim Trachom," Arbeiten aus dem Kaiserlichen Gesundheitsamte, vol. 26, Heft 1 (1907), pp. 44-47.

First Known Use

1966, in the meaning defined at sense 1

Medical Definition

chlamydia

noun

chla·​myd·​ia klə-ˈmid-ē-ə 

1

capitalized : the type genus of the family Chlamydiaceae comprising coccoid to spherical gram-negative intracellular parasitic bacteria and including one (C. trachomatis) that causes or is associated with various diseases of the eye and genitourinary tract including trachoma, lymphogranuloma venereum, cervicitis, and some forms of nongonococcal urethritis

2

plural chlamydiae -ē-ˌē, -ˌī  also chlamydias

a

: a bacterium of the genus Chlamydia

b

: an infection or disease caused by a bacterium of the genus Chlamydia

chlamydial

-ē-əl 

adjective