Urine PCR – Urinary Tract Infection Test

November 18, 2020

UTIs. If you’ve had one, you know how disruptive they can be to life. If you haven’t had one, you still could get one.

Urinary tract infections (UTIs) are one of the most common reasons for patients to see their providers. UTIs are the cause of more than 8.1 million visits to health care providers each year. About 60 percent of women will get one UTI within their lifetime with approximately 20 to 30 percent of women experiencing recurrent UTIs. 12 percent of men will have at least one UTI during their lifetime.

 A UTI develops when bacteria gets into the urine and travels up to your bladder. Large numbers of bacteria live in and around the genital area and can often get into the urine easily––allowing them to travel to the bladder or kidneys. When you have a UTI, the lining of your bladder and urethra become red and irritated just as your throat does when you have a throat infection. This irritation causes symptoms. Most often the symptoms of a UTI are burning with urination, urinary frequency and urinary urgency. Some may experience lower back pain, blood in the urine, cloudy urine or a change in the odor of the urine. If the infection travels up to the kidney, it is termed a kidney infection or pyelonephritis which includes symptoms like fever, nausea, vomiting, severe back pain. Regardless of how far the bacteria go, they can cause problems.

Women are more likely to get UTIs due to the length of their urethras. A shorter urethra means less distance to travel to reach the bladder. However, people of any age and sex can develop a UTI. The likelihood of developing a UTI is increased if you have diabetes, frequent intercourse, bladder or bowel changes, BPH, kidney stones, menopause, poor hydration, difficulty emptying the bladder, pregnancy, immunocompromised conditions or a urinary catheter. 

UTIs are diagnosed by analyzing a sample of your urine. There are three methods to diagnose a UTI using a urine sample. Traditionally a urinalysis and urine culture have been the most common ways to detect a UTI. However, within the last two to three years multiplex PCR-based urine assessment is increasingly being used. The three methods for diagnosing a UTI are:

  • Urinalysis: A quick, in-office test where a dipstick or microscope is used to detect any white blood cells, nitrates or blood in your urine sample. This is a quick look at the urine, but not a very sensitive or specific test to determine what type (if any) bacteria is causing the infection and what best antibiotic should be used to treat that bacteria.
  • Urine culture: Your urine sample is sent off to a lab and the results may take up to seven days to return. At the lab your urine sample is being analyzed in a different and more thorough way. The lab attempts to grow and specifically identify any bacteria from the urine sample and, if so, determine exactly the most sensitive antibiotics to treat/kill the bacteria. This is considered the “gold standard” and is a very sensitive and specific way to diagnose and treat a UTI. 
  • Urine PCR: A Urine PCR test detects the presence of bacteria differently. It is a multiplex polymerase chain reaction (PCR) test which identifies more bacteria than a traditional urine culture in patients with symptoms of a UTI. It is also done using a sample of your urine.

Previously, a urine culture seemed to be the most effective method to detect a UTI. However, studies are beginning to reveal that PCR-based urine tests may be better at diagnosing UTIs– in both identifying and detecting the bacteria responsible for the infections versus the traditional “gold standard” urine culture. The PCR urine test exhibits greater accuracy for the detection of bacteria, identifying bacteria in the urine samples of 36% of patients who had a negative urine culture. Additionally, the PCR urine test has a fast turnaround time, typically results are available in a day, whereas, a urine culture can take up to seven days for results to return. 

A notable study demonstrated the superior detection of bacteria by the PCR urine test versus a urine culture. The urine samples of patients with symptoms of a UTI were tested using a urine culture and a PCR. In the 582 patients that were tested, bacteria was detected and identified in 56% of the patients using a urine PCR. Using a urine culture, only 37% of patients had bacteria detected in their urine. In 175 patients that had a UTI caused by multiple bacteria, the PCR tested detected 166 of those cases whereas the urine culture only detected 39. 

Additionally, the PCR urine test detected 22 out of 24 of the bacteria/organisms that were the cause of the UTI whereas the urine culture detected only 15. The explanation for the more accurate and precise results from PCR test versus a urine culture may be because some bacteria/organisms that can cause a UTI may be slow growing or may require specific growth conditions that may not be available in a lab when attempting to grow bacteria from a urine culture. 

Urine PCR tests are quickly becoming the most accurate way to diagnose and treat UTIs or screen for UTIs if you have urinary symptoms and a UTI is suspected. The sensitivity, accuracy and quick turnaround time of the urine PCR tests are changing the game in how quickly you can be diagnosed, treated and get back to your normal routine versus waiting for results and having your days disrupted by urinary symptoms. 

If you have concerns that you have UTI, have been treated for a UTI that has not resolved, have UTI-like symptoms or have frequent/chronic UTIs– schedule a visit with a provider at Austin Urology Institution where the urine PCR test is available.