False Positive STD Results: Why Do They Happen

STIs are a complex and difficult topic for everyone. If you've had an STI test result come back positive, you know how overwhelming it can be. 

When faced with such a possible STI diagnosis, you want to feel secure with the results in front of you. Why do false positive STD test results happen? Risk factors for false positives or negatives depend on the type of test, how the test is administered, and whether the suspected infection has had time to reach detectable levels in your body.

STI tests generally provide accurate results by design, but they sometimes show an inaccurate diagnosis. Consistent progress in medical technology and advanced science ensures that, by and large, most results reflect an accurate diagnosis. However, no diagnostic test is 100% perfect, which leads to false readings a small percentage of the time. 

By staying informed on how false positives occur, you'll better understand what you can do to improve STI test accuracy for your next screening with Rapid STD Testing. 

What Is a False Positive Test Result?

Inaccurate diagnostic test results fall under one of two categories. A false negative means the test says you're in the clear when you aren't. A false positive result means that the test inaccurately detected the presence of an STI when there is no infection. Either type of false result has its own set of consequences. 

How common is a false positive STD test? STI tests are specifically designed to detect the presence of a disease rather than the lack of it. Therefore, false positives are less likely to occur than false negatives. When it does occur, healthcare professionals call it a reactive result and will recommend further testing. False positives occur because the test itself is flawed or has been otherwise compromised. If you get a false positive and do not get a second test, you could go through unnecessary treatment options specific to the disease for which you tested. Some treatments are harsh, especially when unnecessary.

False negatives present a bigger danger than false positives. When the presence of disease remains undetected after taking a test, then the infection can more easily spread to other sexual partners in the future. It can also damage your health without you knowing the true cause. You may not experience any symptoms from STIs until years later. At that point, they can cause irreversible damage to your reproductive and general health. People without symptoms are at risk of spreading the STI to their sexual partners, continuing the spread. 

Some tests are less accurate than others, with certain varieties delivering false-positive rates in half of all positive results. You may feel shocked at this information and ask yourself, “How can an STD test be wrong?” 

If you feel unsure about either result at any point, getting a second STI screening will put your mind at ease. Even though false positives are rare, some variables will increase their likelihood. A rapid STD test offers a quick and easy way to make a more informed decision about your health. You can find a lab close to you for your convenience. A second test will confirm a diagnosis so that you get the right treatment from your physician. You can securely move forward from there. 

What Causes False Positive STI Tests?

Knowing the potential for error, you may wonder, “how accurate are STD tests?” Accuracy depends on a variety of factors, including: 

• Type, specificity, and sensitivity of the test
• STD being tested
• What part of the body the test sample comes from
• How the test is handled before and after administration

Specificity, or true negative rate, refers to how quickly a screening disqualifies an STI diagnosis in the sample. The higher the percentage of specificity, the less likely the test will produce a false negative. Sensitivity means the amount of time that a screening can detect an infection in a sample. A low-sensitivity test is more likely to provide false positives.

Different diseases have varying degrees of specificity and sensitivity. If you test for bacterial infections, a culture provides a more precise result than a rapid test. Let’s use chlamydia as an example. Can a chlamydia test be false positive? This test has an average sensitivity rate of 86% and a specificity rate of 97%. This means there is a 14% chance of a false negative and a 3% chance of a false positive.

STD Testing Method

The level of accuracy depends in part on the testing method, including:

• Swab test: A healthcare provider uses a cotton swab to swipe an infected area. Swab tests screen for chlamydia, HPV, and gonorrhea. 
• Blood test: A healthcare provider draws blood from your arm to screen for HIV, herpes, or syphilis. 
• Urine test: You collect a sample of your urine for your doctor to test. Urine samples help diagnose trichomoniasis. 
• Same-day STD testing: You purchase a test panel, visit a lab near you to provide samples, and receive your results within one to three business days.  

With each method of STD test, there is room for error. Any cultures you provide may produce a false negative if the infection hasn't reached that area of the body yet.  

Existing Disease

The level of existing disease in the body will also factor into any test's accuracy. Each STD has a different window of time to register on a test.

• Hepatitis: up to six weeks after infection
• HPV: up to a few months
• Gonorrhea and chlamydia: up to two weeks. 
• Syphilis sores: must be tested within three weeks
• Herpes: up to four months
• HIV: between ten days and three months, depending on the type of test. 

If you take a test too soon during this window, you can get a false negative result. When you get a negative STD test but are still worried about your risk of infection, you can take several steps to ensure the accuracy of the result, like taking a 10-panel STD test from Rapid STD Testing. 

How to Avoid Getting False Positive Results

While false positives are less likely than false negatives, there are a few steps you can take to ensure the accuracy of your results every time.

1.  Eliminate anything that could tamper with your final result. Wash your hands thoroughly before handling an at-home testing kit and read the instructions for self-collected samples. If you collect the sample yourself and send it to a testing facility, you could fail to correctly collect the swab or sample, leading to less accurate results.

2.  Follow the directions closely to ensure that you meet every requirement for the test. 

3.  Plan ahead for additional testing. If the two tests show different results, speak with a healthcare provider about your results to learn what steps you should take. You can speak with a doctor at Rapid STD Testing at one of our 2,500 clinics nationwide.

4.  Test at regular intervals or whenever you experience symptoms associated with an STD. Not all people experience obvious symptoms, which allows many STDs to fly under the radar. Testing every three to four months allows a disease to reach detectable levels for a test. It also gives you peace of mind and knowledge to make the right decisions. 

5.  Choose a reputable STD testing center, like those at Rapid STD Testing. With STD results, you need accurate, confidential, fast results. You can visit a clinic near you, provide a sample to a trained professional, and receive results in as little as one day. 

Remember, waiting for your final results can be frustrating and nerve-wracking. Many people worry about positive STD result duration. Do your best to keep your thoughts positive and avoid overthinking about the results while you wait.  

If you test positive, you will need to retest during a second window after completing the prescribed treatment. However, if you suspect you're getting false positive STD test results at any point, speak with your doctor about all the details. They can make a note on your medical records to ensure you get additional testing at an appropriate amount of time, followed by treatment if necessary.  

Stay Informed and Empowered with Rapid STD Testing

Now you understand a little more about why false positive STD test results happen. Are STD tests always accurate? The answer is that while false-positive results are rare, confirmatory testing always helps give you peace of mind no matter the result. Plus, you can get confidential screenings from trained technicians who know how to handle the samples correctly. Call Rapid STD Testing today at (866)-872-1888 to learn more about ordering a rapid test panel and labs near you. Our doctors offer free consultations to guide you through the next steps to take after you get your results. Take control of your sexual health now and in the future!