What is it?
Chlamydia is a sexually transmitted bacterial infection. Not having any symptoms is common. When symptoms do appear, they include pain when urinating, unusual discharge from the vagina, penis or rectum, and abnormal bleeding from the vagina. Even when chlamydia doesn’t cause symptoms, there’s a good chance of it developing into an inflammation of other reproductive organs, such as the uterus or the testicles, which can lead to reduced fertility and other problems.
Chlamydia affects around 3.1% of the population and is more common in women than in men. In 2013, it resulted in 1100 deaths.
What causes it?
Chlamydia is caused by a bacterial infection. It spreads through contact with infected genital fluids: usually this happens during unprotected sex. Despite the fears of some, chlamydia isn’t spread through using the same toilet seat. If the eyes come into contact with infected fluids, an eye infection called trachoma may develop: it is the world’s leading cause for blindness. Chlamydia can also be transmitted from mother to child during childbirth.
What happens during it?
The chlamydia bacteria can’t produce their own energy, so they are completely dependent on their host cells, inside which they live. When a person is infected, the bacteria are “eaten up” by the cells. This means that the bacteria are transported inside the cell in a vesicle. Normally, the cell would send another vesicle containing dangerous substances to fuse with the bacteria-containing vesicle and kill the contents. The chlamydia bacteria protect themselves by stopping this process.
When inside the host, the bacteria grow into bigger versions of themselves and start to replicate. They use the energy of the host cell to do this. Eventually, the cell ruptures and the new, small bacteria are released to infect other cells and to grow and replicate inside them.
Chlamydia can be very persistent. If the host cell is starving, the bacteria will stop dividing and start growing inside the cell. When the cell gets enough nutrients, the bacteria can go back into replicating.
Most symptoms of chlamydia are a result of the body’s reaction to recognizing an invader. When the immune system comes into contact with a microbe it starts to produce cytokines. These molecules provoke inflammation, with the aim of making the vessels in the area become dilated and more permeable, so that more white blood cells will come to the area and help fight the microbe. This is often painful. The unusually large amount of discharge is probably caused by the body trying to protect itself, as the discharge is acidic and many microbes don’t survive in such an environment.
How can it be treated?
Antibiotics are an effective treatment. It would be wise, however, (for many reasons), to avoid having unprotected sex with people who might carry STDs in the first place.
Sources: http://web.uconn.edu/mcbstaff/graf/Student%20presentations/Chlamydia/Chlamydia%20trachomatis.html, http://www.austincc.edu/microbio/2704t/ct, http://www.nhs.uk/conditions/Chlamydia/Pages/Introduction.aspx, https://en.wikipedia.org/wiki/Chlamydia_infection, http://emedicine.medscape.com/article/214823-overview#a3, http://www.news-medical.net/health/Chlamydia-Infection-Pathophysiology.aspx, https://microbewiki.kenyon.edu/index.php/Chlamydia_trachomatis