Chlamydia

Yes, chlamydia is completely curable with antibiotics. The preferred treatment is doxycycline 100 mg twice daily for 7 days; a single 1g dose of azithromycin is an alternative when the full course isn't practical. No clinically significant antibiotic resistance exists for chlamydia: unlike gonorrhea, where resistance is a serious and growing problem. You are generally considered non-contagious 7 days after starting treatment, but you should avoid sex for all 7 days of the doxycycline course and until all of your recent partners have completed their own treatment. Having it once does not make you immune, you can be re-infected the same day treatment ends if you have sex with someone who still has it.

Indefinitely, and this is what makes chlamydia uniquely dangerous. Because most infections cause no symptoms, and because symptoms that do appear are often mild and easily confused with other things (a UTI, normal discharge variation, mild irritation), people can carry and transmit chlamydia for months or even years without suspecting anything is wrong. During that entire time, in women, the infection may be slowly progressing into the upper reproductive tract and accumulating scarring damage. There is no biological clock that clears it on its own, chlamydia does not resolve without treatment. Routine testing is the only way to catch silent infection before it causes harm.

No. Chlamydia trachomatis infects columnar epithelial cells found in the genital tract, rectum, and throat: it is transmitted through sexual contact involving these sites, not through saliva or casual oral contact. Kissing, hugging, sharing drinks or food, or using the same toilet seat does not transmit chlamydia. The bacterium cannot survive outside of human cells, so environmental transmission is not possible. Throat chlamydia is spread through oral sex, not kissing.

No: hormonal contraception of any kind (pills, the patch, the ring, the shot, implants, or hormonal IUDs) prevents pregnancy but provides zero protection against chlamydia or any other sexually transmitted infection. Only barrier methods, condoms used correctly and consistently, reduce chlamydia transmission risk, by approximately 60–70%. If you are on hormonal birth control and sexually active with new or multiple partners, you still need regular STI screening and should use condoms with partners whose STI status is unknown.

Almost always, yes, especially if the infection was caught and treated before it progressed to complications. Chlamydia threatens fertility only when it has advanced to pelvic inflammatory disease (PID) with fallopian tube scarring, and even then, fertility is reduced rather than eliminated in most cases. One episode of PID raises infertility risk by roughly 12%; multiple episodes raise it further. The key is testing early, before PID develops, which is exactly what annual screening for women under 25 is designed to accomplish. If you have been treated for chlamydia and are having difficulty conceiving, a conversation with a reproductive specialist about tubal patency is worthwhile.

Yes: not because the treatment failed, but because chlamydia provides no lasting immunity and re-infection is common. The most frequent scenario is that an infected partner was not tested or did not complete treatment, and the infection passed back and forth. This is why treating all recent partners and avoiding sex for 7 days after treatment begins (and until partners are treated) is the essential companion to your own treatment. If you test positive again within a few months of treatment, the most likely explanation is re-infection, not treatment failure. Antibiotic resistance in chlamydia is extremely rare; re-exposure is the overwhelming cause of recurrent positive tests.

Chlamydia and gonorrhea are both bacterial STIs that often have no symptoms, infect similar anatomic sites (cervix, urethra, rectum, throat), and can cause PID and infertility, which is why they are frequently tested together. The key differences: chlamydia is caused by Chlamydia trachomatis (an intracellular bacterium), while gonorrhea is caused by Neisseria gonorrhoeae (a conventional extracellular bacterium). Gonorrhea causes symptoms more often when they do occur, particularly discharge that tends to be more pronounced and purulent. Most importantly, gonorrhea has developed extensive antibiotic resistance, leaving only one reliably effective treatment regimen (ceftriaxone injection) as of 2024; chlamydia remains curable with oral doxycycline. Co-infection with both is common, roughly 30–50% of people with gonorrhea also test positive for chlamydia.

Rarely, but yes. The primary male complication is epididymitis: inflammation and scarring of the epididymis, the tube that stores and transports sperm from the testicle. Severe or recurrent epididymitis can damage sperm maturation and, in rare cases, cause obstruction that reduces fertility. Orchitis (testicular inflammation) can also occur. The male fertility consequences of chlamydia are far less common and less well-documented than the female equivalents, partly because men are more likely to have symptomatic epididymitis (pain prompts treatment before severe scarring develops) and partly because male fertility is harder to track epidemiologically. Prompt treatment of symptomatic epididymitis essentially eliminates the fertility risk.

Pelvic inflammatory disease (PID) is an infection of the upper female reproductive tract: the uterine lining (endometritis), fallopian tubes (salpingitis), ovaries (oophoritis), and surrounding pelvic tissue. Chlamydia causes it by ascending from the cervix upward into these structures, triggering an inflammatory response. The inflammation itself damages the delicate tissue of the fallopian tubes: not by destroying the tube outright, but by causing scarring and adhesions that narrow or block it. The insidious part is that roughly 70% of PID is subclinical: no fever, no severe pain, no clear signal that something is wrong inside. This silent scarring is exactly what drives the long-term fertility consequences: a woman may discover she has tubal factor infertility years later, with no memory of ever feeling sick.

Yes. A newborn can contract chlamydia during vaginal delivery if the mother has an untreated infection at the time of birth. The two main presentations in newborns are conjunctivitis (ophthalmia neonatorum), a sticky, purulent eye discharge appearing in the first week of life, and pneumonia, appearing between weeks 2 and 12 of life. Chlamydial pneumonia in infants is distinctive: it causes a repetitive, staccato cough without fever and shows diffuse infiltrates on chest X-ray. It is the most common cause of afebrile pneumonia in infants 1–3 months of age. Both conditions are treated with azithromycin and are entirely preventable through prenatal screening and treatment. This is why chlamydia testing at the first prenatal visit is a standard part of prenatal care.