Testing for sexually transmitted infections (STIs)

Originally Published: December 14, 2001 - Last Updated / Reviewed On: November 3, 2005
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Dear Alice,

Is there any test for STD?

Dear Reader,

Yes, there are tests that can diagnose sexually transmitted diseases (STDs) or infections (STIs). While some STIs are caused by bacteria, others are caused by a virus. Screening for bacterial STIs is fairly simple and generally involves collecting a sample of fluid from the infected area. Some viral STIs are screened by drawing blood samples. Other viral STIs, such as herpes and genital warts, are often diagnosed by visual identification of a lesion. Sometimes health care providers scrape the surface with a cotton swab or take a small biopsy. Some STIs, such as HIV, herpes, and syphilis, can be identified by blood tests. After being screened for an STI, it takes a few days or even a couple of weeks to get test results, since the provider's office or clinic often needs to send the sample to a lab for analysis.

Some people decide to get tested because they worry or think they've been exposed to an STI. Some get tested before they decide to have sex with each other. If you have been having unprotected sex or if your partner has, it's smart to be tested. Other people choose to get tested as part of a routine sexual health exam. If someone wants to be tested for STIs, a variety of health care providers can screen for these infections. Typically, though, providers don't automatically test for STIs, and they don't test for every STI, unless they notice, or you mention, something suspicious. This is of concern since some STIs have no symptoms — 80 percent of chlamydia in women is asymptomatic, for example, and herpes is episodic. So, if you think you may have been exposed to an STI, experience possible symptoms, or have concerns, it is important to discuss this with your health care provider. You might say something like this: "I'm really embarrassed, but I'm also worried I may have one or several STIs. I had unprotected intercourse (or anal or oral sex) during the last three months;" or, "I had sex with someone I don't know very well and I'm worried..." Most STIs, however, have an incubation period — this is the time from when a person becomes infected to the time that s/he develops symptoms. The incubation period varies by individual and by strain of the bacteria or virus.

Below is a brief list of the most common STIs. Please note that these are not all of them, and some are more common than others.

Name of STI Type of STI Basic Testing Information Related Q&As
Chlamydia Bacterial The most reliable test involves collecting a culture or specimen from the man's urethra or the woman's cervix.

Urine analysis is also possible that looks for DNA of the bacteria.
Chlamydia?

What is chlamydia?
Gonorrhea

(a.k.a., "the clap," "dose," "drip," "morning dew," "gleet," "hot piss," and "the whites" -- from Changing Bodies, Changing Lives, by Ruth Bell)
Bacterial A sample of fluid is collected from the cervix, urethra, anus, or throat with a swab — depending on whether the infection is from vaginal, anal, or oral sex.

Urine analysis is also possible that looks for DNA of the bacteria.

In men, a sample or culture, known as a Gram Stain or culture, can also be used for diagnosis. This involves using a swab in the urethra.

Gonorrhea

Symptoms of gonorrhea
Syphilis Bacterial A swab of fluid is taken from the Chancre (the lesion that is caused by the bacteria).

Blood drawn three months after possible exposure can detect antibodies.
Late stage syphilis
Trichomoniasis Bacterial In women, a sample of vaginal discharge or pH levels is taken. It may also be detected during a routine Pap smear.

Trichomoniasis is often difficult to detect in men. It is possible to spread the bacteria while it's present in the urethra. Although it can take many weeks, it often resolves on its own.
Tricky trichomonas
Human Immuno-deficiency Syndrome (HIV)

Acquired Immune Deficiency Syndrome (AIDS)
Viral Blood drawn three to six months after possible exposure can detect HIV antibodies. HIV Transmission: When does it show up on a blood test?
Human Papillomavirus (HPV) —the virus responsible for Genital Warts Viral Visual examination of lesions is the most common way to diagnosis warts.

A biopsy is suggested for warts that are persistent.

In women, a Pap smear often detects HPV.
Genital warts

More about genital warts

Testing for herpes and genital warts
Herpes Simplex Virus (HSV)

(a.k.a., Herpes)

HSV-1 generally causes oral herpes, including cold sores and fever blisters.

HSV-2 generally causes genital herpes.

However, both Type-1 and Type-2 can occur in the genitals, oral area, or both.

Viral Visual examination of lesions is the most common way to diagnose herpes.

The most accurate test involves a tissue culture, in which a swab is rubbed over the lesion within 48 hours of the lesion appearing. After 48 hours, the result may be a false negative because symptoms may have had time to heal.

Blood can be drawn and examined for antibodies; however, many standard tests are not accurate.

There are two specific tests that are accurate. Similar to the standard tests, these cannot determine whether the infection is oral or genital. However, since most cases of genital herpes are Type-2, a positive Type-2 result most likely indicates genital herpes. These include:
  • the Herpes Western Blot, which can accurately distinguish between Type-1 and Type-2.
  • Diagnology's POCKIT® (POC stands for "Point Of Care"), meaning that the test can be done in a provider's office to identify HSV-2.
Genital herpes

What is viral shedding?

Testing for asymptomatic herpes

Testing for herpes and genital warts
Hepatitis B Viral Blood is drawn and is examined for antibodies. Hepatitis B


For more detailed information about STIs, including testing and treatment, contact the following resources:

 

American Social Health Association (ASHA)
Centers for Disease Control and Prevention (CDC) National STD and AIDS Hotlines
Hotline: 1.800.342.AIDS (-2437) or 1.800.227.8922 (7-days-a-week, 24 hours)
Spanish Hotline: 1.800.344.SIDA (-7432) [7-days-a-week, 8 AM - 2 AM (EST)]
TTY: 1.800.243.7889 [Monday - Friday, 10 AM - 10 PM (EST)]
National Herpes Hotline
919.361.8488 [(Monday - Friday, 9 AM - 7 PM (EST)]
National Herpes Resource Center
National HPV and Cervical Cancer Prevention Resource Center
Hotline: 919.361.4848 [Monday - Friday, 2 PM - 7 PM (EST)]
An appropriate prescription for STI treatment can be obtained from visiting a health care provider. After the course of medication, one may be tested again, to insure that the infection is gone.

 

Alice