What is a bacterial STI?

A bacterial STI is a sexually transmitted infection caused by bacteria. Bacteria are living organisms that can reproduce on their own. Bacterial STIs are treatable, though they can cause more problems if left untreated. For this reason, early diagnosis and treatment are key.

The most common bacterial STIs are chlamydia, gonorrhea, and syphilis. Common symptoms of bacterial STIs are urethritis (including inflammation of the urethra or painful urination), vaginal discharge, and ulcers or sores in the vaginal or penile area. 

Specifically, gonorrhea and chlamydia may present with mild symptoms or, more commonly in women, no symptoms at all. It’s common for people to contract chlamydia and gonorrhea at the same time. Symptoms, if they occur, may include both urethritis and vaginal discharge from cervicitis (inflammation of the cervix). 

An initial presentation of syphilis, on the other hand, would include a painless genital ulcer that often goes unnoticed, followed by a rash, swollen lymph nodes, and a fever weeks-to-months later. These symptoms will spontaneously resolve even without treatment, but the disease will continue to progress. 

For the most part, bacterial STIs are very curable. Bacterial STIs are often treated with a one-time injectable antibiotic administered by your healthcare provider, though there are also some bacterial STIs that can be treated with antibiotic pills. A number of different antibiotics are effective in treating STIs, and each person should talk with their provider about the correct course of treatment for them. 

In general, treatment for gonorrhea and chlamydia includes both an antibiotic injection and antibiotic pills, while syphilis is treated with an injection of penicillin. If someone has an infection of just chlamydia and no gonorrhea is present, it can be treated with pills alone. 

It’s very rare for someone to die from a bacterial STI, though technically if an infection is left untreated, there is a low risk of serious illness or even death.  But the vast majority of people will have mild-to-moderate symptoms that resolve with proper treatment.

The clinical presentation of bacterial STIs can vary dramatically from person to person. . Some people may have severe symptoms, like pelvic inflammatory disease, while others can live with the STI for a long time and never show any symptoms. The best way to prevent the spread of these infections is to make sure that you’re getting regular STI screens if you are sexually active, and discuss any symptoms promptly with a clinician.