STD Screening: The Basics

Updated November 20, 2018.

STD screening may not be dinner table talk, but if it came up, would you know how to handle it? Everyone who is sexually active should be screened for STDs at some point — but which tests, and when, depend on your personal risk factors. Sometimes testing isn’t necessary. But if it is recommended, and you do get diagnosed, there is some good news: Most STDs are curable, and all of them are treatable.

STDs are sometimes referred to as sexually transmitted infections (STIs). Many providers use this term since there’s less stigma attached to the word infection. It’s possible to have an infection without symptoms, and the infection may cause disease (when you do experience symptoms) in the future. In the absence of symptoms, the only way to diagnose an STI is to screen for it.

• Human Papillomavirus (HPV): The most common STI in the U.S., this virus causes genital warts, although the lesions don’t appear in everyone who has HPV. It’s highly contagious and easily transmitted sexually or even by skin-to-skin contact. When genital warts are present, we can usually make a diagnosis from inspection, but additional testing is sometimes useful, and can include biopsy or colposcopy in women.
• Gonorrhea and Chlamydia: These infections are very common and are often grouped together because they’re screened for at the same time. The infection can be missed, particularly in women because the bacteria that cause them doesn’t always create symptoms. Infections are caused by oral, anal, or genital contact with someone else who has an infection.
• Syphilis: Syphilis is a bacterial infection passed from one person to another by oral, anal, or genital contact with infectious but painless sores that are present during the initial stages of the infection.
• Herpes: There are two strains of the herpes virus: type 1 and type 2. Type 1 has traditionally been associated with oral herpes (cold sores) and type 2 with genital herpes, but recent research has shown that most genital infections are also caused by type 1. A person may have either strain of the virus but never show any symptoms, or may have an “outbreak” with painful sores near his or her mouth, genitals, or anus. Herpes is most commonly transmitted via contact with infectious sores, but in some cases can be transmitted when the infected person has no symptoms at all. Because a person can be contagious even though no lesions are present, taking precautions only when there are visible lesions may not prevent spread of the infection to the partner.
• HIV: This viral infection is transmitted via blood (e.g, in intravenous drug abusers who share needles with infected persons) or sexually, by having unprotected anal or vaginal sex. Very rarely, it can be transmitted by contact with other body fluids.
• Hepatitis C: Hepatitis C is a viral infection that is transmitted most commonly through contact with blood or through skin exposure (e.g., sharing needles or coming into contact with an open wound or sore). Very uncommonly, hepatitis C can be contracted by having sex with someone who has hepatitis C; the risk is about 1 transmission per 190,000 sexual occurrences. This infection can cause chronic liver disease and liver cancer.
• Hepatitis B: Hepatitis B is also a viral infection, transmitted by blood or semen, that can cause liver disease.

Getting a screening test means that we look for an infection when you may not have any symptoms. Just like you get a mammogram, or screen for colon cancer, it’s also important to screen for sexually transmitted infections (depending on your risk). There are no exact recommended times or tests that we recommend for everyone. These testing recommendations depend on your lifestyle and risk level.

Most importantly, get tested to protect yourself, your partner(s), and to stay informed. Getting a diagnosis can alert you to an infection you may not know you had (e.g. many people hepatitis C, probably about 1 million in the U.S., have no idea they have been infected), or that may have long-term effects like infertility. It can also allow you to start treatment if you do have an infection, and create peace of mind when you think you may have been at risk.

There are plenty of tests that make staying informed accessible, but there’s no single test for every STD. Most tests require a urine or blood sample, or a swab of the area where the infection might be present. If you have a sore and we want to pinpoint the cause, a swab can additionally identify whether a specific virus or bacteria is present. There are also “rapid” HIV tests you can buy for home use; results are available in about 20 minutes.

People often say, “Just test for everything.” While that might seem to make sense initially, it’s important to talk to your health care provider about your specific risk factors and lifestyle. There are a few downsides to testing for everything that are important to consider. First of all, tests are expensive, and in a few cases, such as blood testing for herpes, a positive test can be a false positive. False positives may result in unnecessary anxiety when there may be virtually no risk of transmission and no required treatment.

Here are some instances that would prompt a screening test:

• You’re sexually active. Everyone who is sexually active (even if you’ve only ever had one partner and always use protection) should be screened at some point. We recommend an HIV test for everyone who is sexually active. We also suggest women obtain a test for gonorrhea and chlamydia, because, unlike men, they frequently harbor these infections without developing symptoms. Keep in mind that if you’re practicing safe sex and are in a monogamous relationship, you can get tested less frequently.
• You’re having unprotected sex. If you’ve had or want to start having sex — vaginal, anal, or oral — with a new partner, without a condom, it’s a good idea to get tested. Here’s how long after exposure we can get a reliable test result:
  • 2 weeks: gonorrhea and chlamydia (and a pregnancy test too!)
  • 1 week to 3 months: syphilis
  • 6 weeks to 3 months: HIV, hepatitis C and B
• (You might be asking, “What about herpes?” We don’t recommend screening for the herpes virus for most people unless you have an outbreak of sores.)
• You’re involved in riskier relationships. If your partner has a chronic or long-term infection, such as HIV or hepatitis C or B, it’s important to be tested more frequently. If you’re in an open relationship, or you aren’t sure that your partner is monogamous, those are also reasons to be screened regularly. Generally, that means about every 6 months or more depending on your personal situation.
• You engage in high-risk sexual behavior. High-risk behavior includes intimate contact with a sex worker, IV drug user, men who have sex with men, and having multiple partners, or anonymous partners. In these cases, you’re at higher risk for coming into contact with HIV and hepatitis C, along with syphilis, gonorrhea, and chlamydia and should get tested after contact (remember, that includes oral and anal sex, too!)
• You’ve had an infection in the past. You may be more likely to have in infection again, so it’s a good idea to be screened, about 3 months after you’ve been treated, if you are sexually active.
• You’re a baby boomer. Because many baby boomers (people born between 1945 and 1965) may have contracted hepatitis C before we even knew the virus existed and could test for it, and because they may have no symptoms of infection, we recommend all baby boomers be tested once for hepatitis C.
• You have symptoms. This is a good time to have a discussion with your health care provider. Your symptoms and history will allow you to make the best choice about the most informative tests to look for possible causes of your symptoms.

Still have questions? Make an appointment to talk to your PCP today in our judgment-free office.