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Three types of STI tests

Sexually transmitted infections, or STIs, are common in the U.S. and can affect male fertility. It’s important to undergo STI testing and STI screening to receive appropriate treatment, avoid spreading them to others and to help find causes of male-factor infertility. The three main types of STI testing are blood testing, urine testing, and testing via a genital swab. In some cases, a lumbar puncture may also be used. We look into how STI testing works, who should be tested, and which common STIs are tested during screening.

Key takeaways

  • STIs are common in the U.S. and are typically diagnosed using blood testing, urine testing, or a genital swab.
  • STIs commonly tested during screening include chlamydia, HIV, herpes, and syphilis, among others.
  • Even if you don’t have symptoms of an STI, it’s important to follow recommendations for regular STI testing and screening.
  • STI testing and STI screening may be covered by insurance. You can also use at-home STI testing kits.

What is an STI?

STIs are infections that are usually transmitted through vaginal, anal, or oral sex. These infections are common, with one in five people in the U.S. having one in 2018. The numbers of some STIs increased in 2020, with gonorrhea cases growing by 45% since 2016 and syphilis cases increasing by 52%.

STIs vs. STDs

STIs are often referred to as STDs, or sexually transmitted diseases. While some organizations differentiate between them, defining STIs as transmissible infections and STDs as the diseases that may develop from an infection, agencies like the Centers for Disease Control and Prevention use both terms interchangeably. STI testing, STD testing, and STI screening refer to the same tests.

The three methods of STI testing

There are three main tests used to detect STIs, along with a less commonly used method. The STI testing and STI screening you receive will depend on the type of infection your doctor thinks you may have.

Blood testing for STIs

Blood tests can be used to detect syphilis, HIV, herpes, and hepatitis. A blood sample will be taken from your arm and sent to a lab. The test looks for proteins and antibodies in the blood that are present when you have certain infections.

Urine testing for STIs

Urine tests can be used to detect chlamydia, gonorrhea, and trichomoniasis. You’ll pee into a sterile cup, which will then be sent to a lab for analysis. A high white blood cell count in the urine indicates the presence of an infection. Urine testing can also diagnose STIs like gonorrhea by using nucleic acid amplification tests to detect specific genetic materials and identify the infection.

Genital swab for STIs

Genital swabs involve taking samples from the infected area, such as the vagina or cervix in women or the penis or urethra in men. These samples can be used to detect human papillomavirus (HPV), chlamydia, gonorrhea, and herpes by either performing a genetic test on the swab or using the sample to grow bacteria and identify the infection.

Lumbar puncture for STIs

Also known as a spinal tap, lumbar punctures are not often used for STI testing and STI screening. Your doctor may order one if they think you have an advanced stage of syphilis or herpes. The test involves analyzing fluid drawn from your lower spine to look for the infection.

Common STIs tested during screening

These tests will most often be used to detect the following common STIs:

  • chlamydia: If you have chlamydia, you may notice abnormal discharge from your penis or vagina, as well as a burning feeling when you pee. You’ll be tested for chlamydia using either a urine sample or a sample from your vagina obtained via a cotton swab. Treatment is important because, without it, the infection can lead to pelvic inflammation and infertility.
  • gonorrhea: You often won’t have symptoms with gonorrhea; if you do, they may be similar to those of a bladder infection. If gonorrhea infects the rectum, you may experience itching, discharge, and pain during bowel movements. A urine sample is usually used to test for gonorrhea, but a swab of your throat or rectum may be used if you contracted the infection through oral or anal sex.
  • HIV: Human immunodeficiency virus, or HIV, can cause flu-like symptoms and, without treatment, develop into acquired immunodeficiency syndrome (AIDS). You’ll need to be tested to check for HIV, which involves a blood, oral fluid, or urine test.
  • genital herpes: Genital herpes, also known as herpes simplex virus type 2 (HSV-2), is common in the U.S., but many people don’t know they have it since they may have mild or no symptoms. Symptoms may include blisters around the genitals, rectum, or mouth, as well as genital discharge. Your doctor can diagnose herpes by using a blood test, testing a sample from a sore, or visually examining the sores.
  • syphilis: Syphilis occurs in four stages, with symptoms including sores, skin rashes, fever, hair loss, muscle aches, and tiredness. Treatment with antibiotics can prevent the disease from progressing. Syphilis is diagnosed with a blood test or by testing a sample from a sore.
  • trichomoniasis (trich): Trich is very common, but only around 30% of people have symptoms. If you do develop symptoms, they may include itching or soreness of the genitals, burning after peeing, or genital discharge. Trich is diagnosed by testing a swab from the vagina or penis.
  • HPV: This STI, the most common one in the U.S., can cause genital warts and certain cancers. However, many people don’t have symptoms, and there’s no designated test for HPV. You may find out you have HPV through a cervical cancer screening.
  • hepatitis: Hepatitis A, B, and C can all be spread through sexual contact, but this is most common with hepatitis A and B. Symptoms are uncommon but can include nausea, stomach pain, dark-colored urine, jaundice, joint pain, and loss of appetite. A blood test can show if you have or have had hepatitis.

Who should seek STI testing?

In general, you should consider STI testing if you notice STI symptoms, or if you’re:

  • a woman under 25 who’s sexually active
  • pregnant and under 25
  • a man who has sex with men, even if you use condoms
  • planning to freeze your sperm
  • seeking to begin fertility treatments
  • a person who has HIV
  • a person with an increased risk of an STI, including being a young adult with multiple sex partners, a sex worker, or someone who uses recreational drugs
  • someone who’s been exposed to an STI

Groups at higher risk should be tested periodically following current STI screening recommendations.

STI symptoms that should prompt STI testing

STIs often cause no symptoms, so it’s important to follow recommendations for regular STI screening depending on your age and risk level, even if you have no signs of a disease.

You’ll also want to undergo STI testing and STI screening  if you have the following symptoms:

  • abnormal discharge from the vagina or penis
  • itching or pain in your penis or vagina
  • a burning feeling when you pee
  • sores around your genital area
  • for people with ovaries, bleeding when you’re not on your period
  • for people with testes, swollen testicles

These symptoms may be caused by conditions, so it’s important to undergo STI testing and screening to make sure you don’t have an STI.

Cost of STI testing

According to Planned Parenthood, STI testing costs can range anywhere from nothing to $250. Health insurance often covers STI testing and STI screening, and some health centers provide free or affordable testing.

Home STI testing kits, like the one offered by Legacy, cost around $150.

At-home STI testing with Legacy

You can check for STIs on your own with Legacy’s at-home STI testing kit. The $150 STI testing kit provides STI testing for males and delivers results in just 48 hours. It tests for six STIs:

  • chlamydia
  • gonorrhea
  • hepatitis B
  • hepatitis C
  • HIV 1 and 2
  • syphilis

Whether you’re planning to freeze your sperm or want to be sure you’re not exposing your partner to an STI, the STI testing kit is easy to use and can quickly provide you with a diagnosis or peace of mind.

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