Sexually transmitted infections can be caused by:
Sexual activity plays a role in spreading many other infectious agents,
although it's possible to be infected without sexual contact. Examples include
the hepatitis A, B and C viruses, shigella, and Giardia intestinalis.
Anyone who is sexually active risks exposure to a sexually transmitted infection to some degree. Factors that may increase that risk include:
Oral sex may be less risky, but infections can still be transmitted without a latex condom or dental dam. Dental dams — thin, square pieces of rubber made with latex or silicone — prevent skin-to-skin contact.
Sexually transmitted infections (STIs) can have a range of signs and symptoms, including no symptoms. That's why they may go unnoticed until complications occur or a partner is diagnosed. Signs and symptoms that might indicate an STI include:
Signs and symptoms may appear a few days after exposure, or it may take
years before you have any noticeable problems, depending on the organism.
If your sexual history and current signs and symptoms suggest that you have an STI, laboratory tests can identify the cause and detect coinfections you might have contracted.
Testing for a disease in someone who doesn't have symptoms is called screening. Most of the time, STI screening is not a routine part of health care, but there are exceptions:
The second test is needed to confirm that the infection is cured as reinfection by an untreated or undertreated partner is common. A bout of chlamydia doesn't protect you from future exposures. You can catch the infection again and again, so get retested if you have a new partner.
Screening for gonorrhea also is recommended in sexually active women under age 25.
Women with HIV may develop aggressive cervical cancer, so they should have a Pap test within a year of being diagnosed with HIV, and then again six months later.
It's also possible to be infected with an STI yet still test negative,
particularly if you've recently been infected.
STIs caused by bacteria are generally easier to treat. Viral infections can be managed but not always cured. If you're pregnant and have an STI, prompt treatment can prevent or reduce the risk of infection of your baby.
Treatment usually consists of one of the following, depending on the infection:
Once you start antibiotic treatment, it's crucial to follow through. If you don't think you'll be able to take medication as prescribed, tell your doctor. A shorter, simpler treatment regimen may be available.
In addition, it's important to abstain from sex until you've completed treatment and any sores have healed.
Antiviral drugs can keep HIV infection in check for many years. But the virus persists and can still be transmitted, though the risk is lower.
The sooner you start treatment, the more effective it is. Once you start treatment — if you take your medications exactly as directed — it's possible to lower your virus count to nearly undetectable levels.
If you've had an STI, ask your doctor how long after treatment you need
to be retested. Doing so ensures that the treatment worked and that you haven't
There are several ways to avoid or reduce your risk of sexually transmitted infections.
The Centers for Disease Control and Prevention (CDC) recommends the HPV vaccine for girls and boys ages 11 and 12. If not fully vaccinated at ages 11 and 12, the CDC recommends that girls and women through age 26 and boys and men through age 26 receive the vaccine.
The hepatitis B vaccine is usually given to newborns, and the hepatitis A vaccine is recommended for 1-year-olds. Both vaccines are recommended for people who aren't already immune to these diseases and for those who are at increased risk of infection, such as men who have sex with men and IV drug users.
Condoms made from natural membranes are not recommended because they're not as effective at preventing STIs. Keep in mind that while condoms reduce your risk of exposure to most STIs, they provide a lesser degree of protection for STIs involving exposed genital sores, such as human papillomavirus (HPV) or herpes. Also, nonbarrier forms of contraception, such as oral contraceptives or intrauterine devices, don't protect against STIs.
When used to help prevent HIV infection, Truvada is only appropriate if your doctor is certain you don't already have HIV infection.
Your doctor should also test for hepatitis B infection. If you don't have hepatitis B, your doctor may recommend the hepatitis B vaccine if you haven't had it yet. If you have hepatitis B, your doctor should test your kidney function before prescribing Truvada.
Truvada must be taken daily, exactly as prescribed, and you'll need
follow-up HIV and kidney function testing every few months. Truvada should only
be used along with other prevention strategies such as condom use every time
you have sex.