Testing for sexually transmitted infections (STIs)

Dear Reader,

The very short answer to your question is that yes, there are tests that can diagnose sexually transmitted diseases (STDs also referred to as sexually transmitted infections or STIs). There are multiple ways health care providers test for STIs and most are quick and painless. Some STIs can be accurately identified by a variety of methods including blood tests, fluid samples, urine tests, or visual identification of symptoms. After testing is complete, it typically takes anywhere from a few days to a couple of weeks for a lab to analyze the sample and to get the results back (especially if it is sent out for lab analysis). While you wait for your results, your provider may be able to answer any questions and make recommendations on what to do next. Still curious? Want to know more? Read on!

There are many reasons why someone might consider getting tested for STIs. For example, some people decide to get tested because they’re concerned they've been exposed to an STI. Others get tested before they decide to have sex with a new partner. And, many people choose to get tested as just part of a routine sexual health exam. In any case and no matter the reason, talking to a medical professional will help determine what makes sense for you if you’d like to get tested. Why is that a wise step? Providers may not automatically test for STIs during routine screenings and they might not test for every STI. It may also be helpful to keep in mind that some STIs have no obvious symptoms — for example, the majority of cases of vaginal chlamydia are asymptomatic, and herpes is episodic and might be missed during an exam unless you’re having an active outbreak. So if you are interested in STI testing, for whatever the reason, just ask!

Some folks could find this conversation to be a little bit awkward, but you might say something like this: "I'm kind of embarrassed, but I'm also worried I may have an STI;" or, “I had unprotected sex during the last three months and I'm a bit anxious;" or, "I had sex with someone I don't know very well and I'm worried..." Based on your potential risk for exposure to various STIs, your provider can either help to assuage your concerns or can recommend specific STI tests and give you advice on the next steps you can take.

On to more about testing! Here’s a brief list of some of the most common STIs and methods of testing. It’s good to note that this list isn’t exhaustive and some are more common than others.

Tests for bacterial STIs:

• Chlamydia – The most reliable test for this infection involves collecting a culture from the urethra of the penis or the cervix of the vagina and sending the specimen for lab testing. Alternatively, urine analysis can also be completed, which may identify the presence of chlamydia DNA.
• Gonorrhea – Depending on the suspected mode of transmission (vaginal, anal, or oral sex), a sample of fluid is swabbed from the cervix, urethra, anus, or throat and tested. Similar to chlamydia, urine analysis might also be able to identify gonorrhea DNA, especially if signs point to a genital infection. Because the symptoms are sometimes difficult to pin down, it’s recommended that testing occurs as soon as possible after a potential exposure to avoid long-term complications.
• Syphilis – In the earlier stages of infection, a swab can be taken from a chancre (a lesion or rash characteristic of a syphilis infection) and sent for lab testing. However, sometimes early symptoms might be missed or even absent. In these cases, blood can be drawn as soon as three months after a suspected exposure to test for antibodies.

Tests for viral STIs:

• Human immunodeficiency virus (HIV) – A blood test completed in a lab can accurately detect antibodies to the HIV virus as early as three months after a potential exposure. Additional HIV tests include antigen tests, at-home tests, or rapid tests, often administered in community health center settings.
• Human papillomavirus (HPV) – HPV is responsible for genital warts and many cases of cervical cancer. Genital warts are most commonly diagnosed though a visual examination is used to identify the warts. Currently, a blood test is not available for HPV, but routine Pap smears can detect the HPV in cervical cells (which may indicate pre-cancerous or cancerous changes in the cervix). A biopsy might be recommended for areas with atypical cellular changes that are particularly persistent.
• Herpes simplex virus (HSV) – The most accurate test involves a visual exam and swabbing a newly erupted lesion (within 48 hours) for tissue culture testing. Though blood tests are available to detect HSV antibodies, the accuracy of different tests can vary, it’s not recommended as routine testing for all people, and many don’t distinguish between type-1 or type-2. For more specific recommendations, check out the American Sexual Health Association’s (ASHA) Herpes Testing information.
• Hepatitis B – While hepatitis A and C can also be sexually transmitted, hepatitis B is the most common STI among the three strains. A blood test is available to check for antibodies to the hepatitis B virus.

Tests for parasitic STIs:

• Trichomoniasis – A sample of vaginal discharge can be taken to test for the offending organism, or to test for abnormally high vaginal pH levels characteristic of this type of infection. Trichomoniasis may be detected incidentally during a Pap test. It's more difficult to accurately test for a trichomoniasis infection in the penile urethra, so often all sexual partners are treated even if infection is only confirmed in one.
• Pubic lice – These nether region squatters can cause itching and irritation. The identification of public lice includes finding a “crab” louse or egg (nit) attached to hair in the genital region by a medical professional. The lice and nits can be very small, and sometimes a magnifying lens is needed to spot them.
• Scabies – Scabies in adults is another parasitic condition that can be transmitted sexually. A positive diagnosis includes examining a tell-tale characteristic rash and burrows the critters leave behind, as well as identifying the culprit mites, mite eggs, or mite poo by scraping the affected skin and looking at it under a microscope.

Determining what STIs you’re at risk for with your health care provider and getting tested can help reduce anxiety about not knowing your status, the likelihood of transmitting any infections to partners, get appropriate treatment for positive diagnosis quickly, and get more information on how to protect yourself and others during sex. All in all, a great question! For more detailed information about STIs, including symptoms, testing, and treatment, take a look at the Sexually transmitted infections (STIs) category of the Go Ask Alice! Sexual and Reproductive Health archives and consider taking a look at the Centers for Disease Control and Prevention (CDC) STD Fact Sheets.

Hope this satisfies your testing queries!