This is a complex and evolving topic. Readers are encouraged to supplement the material found here with other high quality sources of information and resources such as CDC’s STD homepage: https://www.cdc.gov/std/default.htm.
Sexually transmitted infections are spread by sexual contact. Some are more common than others, and most are easily preventable. The more different people with whom you have sexual contact, the more likely you are to encounter a sexually transmitted infection. In addition, people should refrain from sexual contact if they have any kind of sore or rash. Honestly reviewing sexual histories with partners prior to getting naked together is a good idea. Many couples chose to get tested for STI’s prior to initiating physical intimacy. This is a very good, but not foolproof strategy because not every STI is always detectable. Good strategies to manage all STI’s exist, however not all are curable. In the end, each individual that chooses to become sexually active must accept personal responsibility for the fact that they may acquire or transmit an STI at some point.
Chlamydia and Gonorrhea
Chlamydia and gonorrhea are bacterial infections that affect both men and women. They can involve the throat, penis, vagina/cervix or anus depending on which site is infected on the partner and what sort of sex people have. If the infected partner has a urethral (penis) infection and sex includes penile-vaginal intercourse, the recipient may develop a vaginal or cervical infection. Condoms are very effective at preventing transmission.
Most people don’t experience any symptoms. Men are more likely to experience symptoms – such as burning with urination, or penile discharge – than women. When present, symptoms of vagina/cervical infections include abnormal vaginal discharge or bleeding, painful urination, and painful sex. Unfortunately, women often have no symptoms and their infections therefore go undetected and untreated. Chlamydia, one of the most commons STDs, can have many long-term and serious health risks for women. If these infections go untreated, they can lead to pelvic inflammatory disease, which can cause infertility due to scar tissue. In a pregnant woman, Chlamydia and gonorrhea may cause infection of the fetus, early labor, and infection of the baby’s eyes at birth.
Gonorrhea and chlamydia can be detected either by asymptomatic screening or diagnostic testing. Screening is getting tested for STI’s even though you don’t have any symptoms. This is advisable for sexually active people that have more than one partner. It is important to give a thorough sexual history so that the right tests are done and right body parts are screened. Testing may be as easy as providing a urine specimen. If either infection is detected, it can usually be easily and definitively treated with antibiotics. Diagnostic testing is done when symptoms are present. Usually, when symptom history is compelling, treatment is provided to the symptomatic individual, and, often, partner, even before results are obtained.
Human immunodeficiency virus (HIV) causes AIDS. It is spread in blood and body fluids. Behaviors that put you at risk of acquiring HIV include intravenous drug use (sharing needles) and having sex without condoms, especially anal sex. Blood transfusions no longer pose a true risk for transmitting this virus.
People that are sexually active should consider having an HIV test at least once, and people at higher risk should be tested with greater frequency (see: https://wwwn.cdc.gov/hivrisk/).
There have been some very exciting advances in HIV prevention and treatment in the past few years. In addition to tried and true methods such as latex condoms, new treatment strategies such as the regimens known as Pre-Exposure Prophylaxis (PrEP) and Post Exposure Prophylaxis (PEP) are helping people prevent acquiring HIV. If you are considering sex with a partner known to be HIV positive or engage in anonymous sex or other types of high-risk activities, talk to a medical provider about PrEP.
Syphilis is rare, but rates are currently on the rise. Treated early, it can be cured. Without treatment, it can have devastating effects. It is spread by direct contact with a syphilis sore during vaginal, anal or oral sex. The first symptom is usually a firm, round, painless sore (chancre) at the site of infection. If the infection persists untreated, other symptoms such as skin rash, enlarged lymph nodes and fever may occur (secondary syphilis). More advanced symptoms can involve the heart, brain and other organs.
Latex condoms are fairly effective in preventing transmission, but they only cover what they cover when they cover it. Per the CDC website: “Any sexually active person can get syphilis through unprotected vaginal, anal, or oral sex. Have an honest and open talk with your health care provider and ask whether you should be tested for syphilis or other STDs.” Blood tests can diagnose syphilis, and antibiotics can cure it.
Genital herpes can be caused by either of two types of herpes simplex virus: HSV-1 or HSV-2. It is spread by skin-to-skin contact with someone that is infected. About 60% of the adult population is infected with HSV-1 and, per CDC, more than one out of every six people aged 14 to 49 years have genital herpes. Many people with herpes infections don’t realize they are infected or contagious because they haven’t had recognized symptoms ever or recently. HSV-l is also the virus that causes cold sores (orolabial herpes). Herpes can be spread from the mouth of one partner to the genitalia of the other partner by oral sex, even without an active cold sore.
The only way to definitely prevent herpes transmission is to avoid intimate contact with others. Being in a long term mutually monogamous relationship is also relatively protective. Barrier methods such as latex condoms are fairly effective in preventing transmission, but they only cover what they cover when they cover it.
Most people that become infected with genital herpes have no symptoms or only very mild symptoms. When symptomatic, herpes can cause sore, burning or tender skin, often with redness and sometimes with crops of tiny blisters that rupture after a few days. There is no cure for herpes, but there are medicines that decrease the duration and intensity of outbreaks. These medicines are most effective when started early in an outbreak, so seeking prompt medical attention for any genital rash or pain is advisable. It is not always possible to make an immediate, definitive diagnosis. Almost everyone that has herpes learns to manage the infection and most have very normal sexual lives. People that have frequent outbreaks should talk to their medical provider about taking daily medication to suppress outbreaks.
Human Papilloma Virus (HPV)
There are many different types of HPV that can be transmitted sexually, usually be skin to skin contact. Most infections don’t cause any symptoms or visible signs, and may not be detectable be conventional medical examination techniques. Whether or not they are visible or symptomatic, they can be spread to others in whom the infection may behave differently (i.e., cause symptoms or signs). Most people will acquire and clear at least one type of HPV in their lifetimes.
Some types of HPV may cause genital warts. These are bumpy, flesh-colored growths on or near the genitalia or anus. They are usually asymptomatic, but may be itchy or bleed after trauma. They can be treated using various techniques, usually via careful application of liquid nitrogen by a trained medical provider. They usually go away within two years. They types of HPV that cause warts are very low risk for causing cancer.
Some types of HPV, if present and undetected for extended periods of time, usually 10 years or more, can cause cancer of the cervix, anus, or penis. HPV is also implicated as a cause of the majority of cases of head and neck cancer. Most of the infections with these types of HPV, though, clear on their own without causing cancer or other complications. Regular PAP smear on standard recommended schedules are highly effective at early detection of infections that can lead to cervical cancer. People that receive anal sex should discuss screening with their medical care provider. Early detection of these infections, and early pre-cancerous changes they can cause, usually leads to very successful outcomes.
There exist highly effective HPV vaccines. Vaccination is ideally received prior to having any sexual contact or early in one’s sex life because it does not work against types of HPV to which you have already been exposed. It can prevent acquiring the types of HPV most likely to cause cancer and genital warts.
This is a less common sexually transmitted vaginitis. Symptoms include a foul-smelling green discharge and burning sensation in the vagina. You and your partner will both require antibiotic treatment.