How do the tests determine if You have STD(s)?

Key Takeaways

• Different STDs require different types of tests, such as blood tests, urine samples, and swabs.
• Some tests are more reliable than others depending on factors like the stage of infection and the testing method.
• Early testing and treatment can prevent complications from STDs.
• Regular testing is essential for sexually active individuals, especially after unprotected sex.

If you're feeling anxious after an unexpected sexual encounter or experiencing unusual symptoms down there, you're not alone.

Sexually transmitted diseases (STDs) can affect anyone, and getting tested is the only way to know for sure if you have one.

This guide will walk you through how STD tests work, what to expect, and how to understand the results.

Understanding STD Tests: Key Concepts

Before we explain the various tests and assess their reliability, let's discuss some basic concepts to help you understand the quality of the tests you get for STDs. After all, the better the reliability of the STD tests, the better the treatment you will receive.

When we talk about how reliable a test is, we usually look at two things: Specificity and Sensitivity¹.

An ideal STD test should:

• Diagnose all or most of the people with an infection as positive (i.e., have a high Sensitivity % in its results).
• Accurately identify all or most people without an infection as negative (i.e., have a high Specificity % in its results).

This minimizes the number of mistakes. That means avoiding both false positives, where someone is wrongly told they have an infection, and false negatives, where someone with an infection is mistakenly told they don't.

Nucleic Acid Amplification Tests (NAATs)

One of the most common and reliable types of STD tests is Nucleic Acid Amplification Tests (NAATs)².

NAATs are a highly sensitive and specific method for detecting STDs. They work by identifying the presence of an infection through the analysis of a particular molecule: Nucleic acid. Nucleic acid is an organism's genetic material (DNA or RNA) unique to each type of bacteria or virus.

Here's how NAATs differ from other methods of STD testing:

• Traditional methods like culture tests rely on growing the bacteria or virus in a lab environment. This process can take days or even weeks and may not be effective for all types of STDs.
• NAATs directly detect the specific nucleic acid of the pathogen, regardless of whether it's alive or dead. This allows for faster and more accurate results, even in cases where the organism is too complex to grow in a culture.

NAATs are the gold standard for diagnosing many STDs, including Chlamydia and Gonorrhea, due to their high sensitivity and specificity. This makes them a valuable tool for ensuring accurate diagnoses and promoting effective treatment.

The Top 10 STDs and How They're Tested

STD testing or screening involves collecting a sample of bodily fluids, such as urine, blood, or a swab. Then, a medic analyzes these fluids in a lab to check for the presence of an STD.

The specific test used will depend on the type of STD being investigated. Here's a breakdown of how tests work for some of the most common STDs.

Chlamydia

Types of Tests

This STD is typically diagnosed through one of the following methods:

• Nucleic acid amplification tests (NAATs)
• Urine tests
• Swab tests

How do these Tests Work?

• NAATs: It detects the DNA of the bacteria Chlamydia trachomatis.
• Urine test: The doctors analyze the urine sample for the presence of bacteria specific to Chlamydia.
• Swab Test: A healthcare provider collects a sample from the affected area (e.g., cervix, urethra, or throat) using a swab and tests for the presence of Chlamydia trachomatis DNA.

Reliability

NAATs are considered the most accurate and reliable tests³ for diagnosing Chlamydia. They have high sensitivity and specificity as they can correctly identify those with or without the infection.

While urine and swab tests are highly accurate, especially when done correctly, factors such as recent antibiotic use or testing too soon after exposure can affect their effectiveness.

The testing provided through saferstdtesting.com's preferred private testing vendors employs Nucleic Acid Amplification Tests (NAATs) on urine samples for Chlamydia, ensuring high accuracy in detection.

These NAAT tests boast a specificity of 99% and sensitivity of 99%, making them a reliable choice for diagnosing this STD.

Gonorrhea

Types of Tests:

• Urine test
• Swab test
• NAATs

How do these Tests Work?

• Urine Test: A urine sample is collected and tested using NAATs, which can detect the genetic material of Neisseria gonorrhoeae in the sample. This is a non-invasive method suitable for both men and women.
• Swab Test: In this scenario, a physician gets samples from the cervix, urethra, rectum, or throat using a swab. These samples are tested using NAATs or other methods.
• NAATs: NAATs are highly sensitive tests that detect the genetic material of Neisseria gonorrhoeae from urine or swab samples. NAATs are considered the most accurate method for diagnosing Gonorrhea and can detect the infection in asymptomatic individuals as well.

Reliability

For Gonorrhea, NAAT is the go-to test. It's highly reliable and can detect the infection even before symptoms show up.

Tests offered through saferstdtesting.com's preferred private testing vendor utilize the FDA-approved Nucleic Acid Amplification Test (NAAT) on urine samples for Gonorrhea, achieving a specificity accuracy of 99% and a sensitivity accuracy of 99%.

This means you can be confident in your results, whether they're positive or negative.

Hepatitis A

Types of Tests

The primary method for testing Hepatitis A virus (HAV) is through these blood tests⁴:

• Anti-HAV IgM
• Anti-HAV IgG

How do these Tests Work?

• Anti-HAV IgM: This test helps identify antibodies that appear in the blood about two weeks after infection and usually disappear within about six months. A positive result indicates an acute illness.
• Anti-HAV IgG: It detects antibodies that appear later in the infection and can remain in the blood for many years, indicating immunity to the virus due to vaccination or past infection.

Reliability

Both blood tests are reliable because they provide information about recent or past infections and immunity.

The FDA-approved Anti-HAV IgM test offered through saferstdtesting.com's preferred private testing vendor(s) uses a blood sample and provides results with both specificity and sensitivity accuracy of 95%.

Hepatitis B

Types of Tests

To diagnose Hepatitis B, your physician will conduct various blood tests⁵ to check for specific antigens and antibodies. An antigen is a substance that triggers an immune response, indicating an active infection.

At the same time, an antibody is a protein the immune system produces to fight off an infection or indicate past exposure or immunity.

Some of the common tests your doctor may use to diagnose Hepatitis B include:

• Hepatitis B surface antigen (HBsAg)
• Hepatitis B surface antibody (anti-HBs)
• Hepatitis B core antibody (anti-HBc)

How do these Tests Work?

• Hepatitis B Surface Antigen (HBsAg): This test measures the presence of the surface antigen, indicating that the virus is currently in the body, either due to an active or chronic infection.
• Hepatitis B Surface Antibody (anti-HBs): This test looks for antibodies produced either after vaccination or from a previous Hepatitis B infection. A positive result shows that you're immune to the virus.
• Hepatitis B Core Antibody (anti-HBc): This test detects antibodies against the core protein of the Hepatitis B virus. A positive result indicates that the person has either had a past or current Hepatitis B infection. It helps distinguish between individuals who have been vaccinated (who will not have core antibodies) and those who have had an actual infection.

It is worth mentioning that the surface antibody test (anti-HBs) shows if you're immune to hepatitis B, either because you've been vaccinated or had the infection in the past.

On the other hand, the core antibody test (anti-HBc) tells us if you've ever been exposed to the virus, which can be a sign of a current or past infection.

Reliability

An accurate Hepatitis B diagnosis involves a combination of tests to assess current infection, past exposure, and immunity.

The FDA-approved Hepatitis B test offered through saferstdtesting.com's preferred private testing vendor(s) uses a blood sample and provides results with a specificity accuracy of 99% and a sensitivity accuracy of 88%.

Hepatitis C

Types of Tests

• Anti-HCV
• HCV RNA
• HCV Genotype Test

How do these Tests Work?

• Anti-HCV: This is the initial screening test that detects antibodies against the Hepatitis C virus in the blood. A positive result indicates past exposure to the virus, but it does not confirm an active infection.
• HCV RNA: If the antibody test is positive, your doctor will perform an HCV RNA test to confirm whether you have an active infection and measures the viral load.
• HCV Genotype Test: This test helps the physician determine the genotype or strain of the Hepatitis C virus you may have.

Reliability

RNA testing is the most reliable method, as it confirms whether the virus is still active in your system.

In addition, this FDA-approved test offered through saferstdtesting.com's preferred private testing vendor(s) uses blood samples and provides results with a specificity accuracy of 99.99% and a sensitivity accuracy of 100%.

Herpes Simplex Virus (HSV) – Oral (Type 1)

Types of Tests

• Viral culture
• Polymerase chain reaction (PCR)
• Chemiluminescence immunoassay (CLIA) test for Herpes Type 1.

How do these Tests Work?

• Viral Culture: This test involves collecting a sample from an active sore or blister during an active outbreak and test it in a lab to grow the virus.
• Polymerase Chain Reaction (PCR): This test detects the genetic material of HSV-1. PCR is more sensitive and can detect even tiny amounts of the virus.
• Chemiluminescence Immunoassay (CLIA) Test: This test⁶ detects antibodies to HSV-1, indicating a previous or ongoing infection. It uses chemiluminescent technology to enhance detection and can differentiate between HSV-1 and HSV-2 infections.

Reliability

The most reliable test for diagnosing active HSV-1 infections is the PCR test, which detects the genetic material of the virus. Antibody tests, like the CLIA test, are useful for identifying past infections or exposure.

The FDA-approved HSV-1 CLIA test offered through saferstdtesting.com's preferred private testing vendor(s) uses a blood sample and provides results with a specificity accuracy of 97% and a sensitivity accuracy of 96%.

It is also able to differentiate between oral herpes (HSV-1) and genital herpes (HSV-2).

Herpes Simplex Virus (HSV) – Genital (Type 2)

Types of Tests

• Viral culture
• Polymerase chain reaction (PCR)
• HSV-2 Type-Specific Glycoprotein G Antibody Test (HSV-2 gG)
• Chemiluminescence Immunoassay (CLIA) Test for Herpes Type 2

How do these Tests Work?

These tests operate similarly to those used for HSV-1, except for the HSV-2 gG Antibody test.

• HSV-2 gG: A more specific version of the antibody test that targets glycoprotein G, a protein found specifically in HSV-2. It helps distinguish between HSV-1 and HSV-2 infections.
• Chemiluminescence Immunoassay (CLIA) Test: This test is also used to detect antibodies against HSV-2, potentially including the HSV-2 gG test. It uses chemiluminescent technology to enhance the sensitivity and specificity of the test.

Reliability

For HSV-2, the most reliable tests are PCR for active infections and type-specific antibody tests (such as HSV-2 gG) for determining past infections or exposure.

The FDA-approved HSV-2 CLIA test offered through saferstdtesting.com's preferred private testing vendor(s) uses a blood sample and provides results with a specificity accuracy of 98% and a sensitivity accuracy of 97%.

HIV-1

Types of Tests Used

• Blood test (antibody or antigen/antibody combination test)
• Oral swab.

How It Works

The antigen/antibody test detects HIV antigens and antibodies. Early detection can be done through RNA tests, which identify the virus before antibodies develop.

The FDA-approved 4th generation antigen/antibody test offered through saferstdtesting.com's preferred private testing vendor(s) uses a blood sample. It provides results with a specificity accuracy of 99-100% and a sensitivity accuracy of 100%.

It also offers an HIV RNA Early Detection blood test option that can be completed as early as 9 to 11 days after exposure, with results showing a specificity accuracy of 100% and a sensitivity accuracy of 99.83%.

Reliability

Modern HIV tests are highly accurate, particularly the antigen/antibody combination tests, which can detect infections sooner than antibody-only tests.

HIV-2

Types of Tests

• Blood test
• Oral swab.

How It Works

Similar to HIV-1, tests for HIV-2 also check for antibodies and antigens. However, due to differences in the viruses, the physician may have to conduct specialized tests.

Reliability

Tests for HIV-2 are just as reliable as those for HIV-1, though HIV-2 is less common and often found in specific regions.

The FDA-approved 4th generation antigen/antibody test offered through saferstdtesting.com's preferred private testing vendor(s) uses a blood sample. It provides results with a specificity accuracy of 99-100% and a sensitivity accuracy of 100%.

Additionally, it offers an HIV RNA Early Detection blood test option that can be completed as early as 9 to 11 days after exposure, with results showing a specificity accuracy of 100% and a sensitivity accuracy of 99.83%.

Syphilis

Types of Tests

• Nontreponemal Tests
• Treponemal Tests.

How do these Tests Work?

1. Nontreponemal Test

This is a type of blood test used to screen for Syphilis, a sexually transmitted infection caused by the bacterium Treponema pallidum. Common nontreponemal tests⁷ include:

• Rapid Plasma Reagin (RPR) Test: This test detects antibodies produced by the body in response to the Syphilis infection. It's often used to screen for the disease in its early stages.

The FDA-approved RPR test offered through saferstdtesting.com's preferred private testing vendor(s) uses a blood sample and provides results with a specificity accuracy of 91% and a sensitivity accuracy of 95%.

• Venereal Disease Research Laboratory (VDRL) Test: This test also detects antibodies present in response to Syphilis infection. It is used to diagnose active infections and can be conducted using either a blood or cerebrospinal fluid (CSF) sample.

2. Treponemal Test: This test pinpoints the exact bacteria that causes Syphilis, which is called Treponema pallidum. Doctors use this test to double-check a diagnosis after a preliminary test shows a possible infection.

Reliability:

A combination of both Nontreponemal and Treponemal tests ensures high accuracy in diagnosing Syphilis, with nontreponemal tests offering valuable screening and treponemal tests providing confirmation.

Other Common STDs

Trichomoniasis

Types of Tests

• Microscopic examination
• Rapid antigen test
• Nucleic acid amplification test.

How do these Tests Work?

• Microscopic Examination: A healthcare provider looks at a sample of vaginal or urethral fluid under a microscope. This test can spot live, moving parasites, which is a sign of infection.
• Rapid Antigen Test: Detects specific proteins produced by the parasite using a swab sample.
• Nucleic Acid Amplification Test (NAAT): A NAAT detects the DNA of the Trichomonas vaginalis parasite from a swab sample.

Reliability

NAAT offers high sensitivity, making it the most reliable test for Trichomoniasis. On the other hand, rapid tests and wet mounts are useful in settings where immediate results are necessary.

Mycoplasma Genitalium

Types of Tests

• NAAT
• Culture
• Resistance-Guided NAAT⁸

How do these Tests Work?

• NAAT: Detects the bacteria responsible for this infection using a swab sample from the genital area or urine sample.
• Culture: Mycoplasma genitalium can be grown in a laboratory culture from genital swab samples.
• Resistance-Guided NAAT: In addition to detecting the presence of Mycoplasma genitalium, this test identifies mutations associated with resistance to antibiotics using a swab or urine sample.

Reliability

NAAT and resistance-guided NAAT are the most reliable tests for diagnosing Mycoplasma genitalium.

Human Papillomavirus (HPV)

Types of Tests:

• Pap smear
• HPV DNA test

How do these Tests Work?

• Pap Smear: This test looks for abnormal cells on the cervix that could be caused by an HPV infection. A healthcare provider collects a sample from the cervix using a swab. The sample is then examined under a microscope.
• HPV DNA Test: This test checks for the DNA of the HPV virus in cervical cells. A swab sample is taken from the cervix to see if the virus is present. It is especially useful for detecting high-risk HPV types that can lead to cancer.

Reliability

Pap smears and HPV tests are effective at detecting high-risk HPV types that can lead to cancer.

Summary

Whether it's a urine sample, swab, or blood test, early detection through regular testing is key to managing and treating STDs effectively. Don't hesitate to talk to a healthcare professional about your concerns and get tested as soon as possible after exposure.

You won't know if you need treatment till you test and know if you, in fact, have an STD.

Feeling unsure about testing? Do not worry; at SaferSTDTesting.com, we have all the information you need to explore your options and stay safe.