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

Syphilis cases rose by 34% from the previous year, to more than 35,000, and chlamydia cases by 16% to more than 216,000. —Fox News, 7 Mar. 2024

According to data from San Mateo County, in the last quarter of 2023, local chlamydia cases increased 11% among men and 7% among women, totaling 1,995 cases. —Ryan MacAsero, The Mercury News, 27 Feb. 2024

The treatment was more effective against chlamydia and syphilis than gonorrhea. —Sara Reardon, Scientific American, 6 Oct. 2023

In the United States, more than 2.5 million cases of syphilis, gonorrhea, and chlamydia were reported in 2022, according to the Centers for Disease Control and Prevention, a number that has been relatively stable for years. —Frances Vinall, Washington Post, 7 Feb. 2024

That could be a sign of an STI such as trichomoniasis, chlamydia, or gonorrhea, or of the infection bacterial vaginosis (BV). —Mara Santilli, SELF, 26 Jan. 2024

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, 22 Feb. 2024

But while chlamydia cases held steady and reported cases of gonorrhea decreased in 2022, syphilis cases continued to climb to the highest level in decades, with a 17% percent jump in one year. —Deidre McPhillips, CNN, 30 Jan. 2024

Rates of STIs, including syphilis, chlamydia, and gonorrhea, have been skyrocketing for years. —Beth Mole, Ars Technica, 22 Nov. 2023

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