1. Health
Send to a Friend via Email
You can opt-out at any time. Please refer to our privacy policy for contact information.

Discuss in my forum

Is chlamydia caused by bacteria or a virus?


Updated February 04, 2014

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

Question: Is chlamydia caused by bacteria or a virus?
Answer: Chlamydia trachomatis, the organism that causes both chlamydia and lymphogranuloma venereum infections, is a bacterium, but in some ways it's one that acts more like a virus. It is virus-like, because it is dependent on molecules from its host organism to reproduce.

Chlamydia can not survive without humans, because it needs ATP, an energy molecule, to reproduce -- as well as other nutrients and supplies that it can't make it on its own. Basically, chlamydia treats the insides of human cells as great big grocery stores, and, since the bacteria can't live without groceries, C. trachomatis is as an obligate (can't survive without) intracellular (living inside cells) parasite (where it takes but does not give back).

Chlamydia travels between cells, and between people, in the form of an elementary body, which is a small, dense, spore-like, metabolically-inactive structure, almost like a virus, that doesn't do much of anything. It's infectious but inactive. When it enters a host cell, it changes into a reticulate body and uses supplies from the host cell to make copies of itself inside the cell. These reticulate bodies can grow, divide, and metabolize, but they're not infectious. Infections can persist in this manner for a while, or, once there are enough copies, the reticulate bodies can turn back into elementary bodies, burst the cell open, and escape to infect new cells or new people.

A . Zomorodipour. "Obligate intracellular parasites: Rickettsia prowazekii and Chlamydia trachomatis. " FEBS Letters , Volume 452 , Issue 2 , Pages 11 - 15
Subtil A, Dautry-Varsat A."Chlamydia: five years A.G. (after genome)." Curr Opin Microbiol. 2004 Feb;7(1):85-92. Review.
L.A. Page "The Chlamydiae" in Wm. M. O'leary(Ed.), Practical Handbook of Microbiology (pp.187-194). Boca Raton, FL: CRC Press.

  1. About.com
  2. Health
  3. Sexually Transmitted Diseases (STDs)
  4. Bacterial Diseases
  5. Chlamydia
  6. Is Chlamydia Caused By Bacteria or A Virus?

©2014 About.com. All rights reserved.

We comply with the HONcode standard
for trustworthy health
information: verify here.