
This story may sound familiar: you recognize all of the symptoms of a UTI so you make a doctor’s appointment. Once at the doctor, you are given a test–usually the dipstick test, and if results are inconclusive likely a urine culture–which despite your abundance of symptoms reads negative. Being told your tests are negative, you are sent home without treatment. Symptoms often will continue to persist and the disease process may progress.
If this story resonates with you it may bring you solace to hear that you are not alone in this experience. As a matter of fact, there is a high chance that your testing was inaccurate and you do have a UTI. It may come as a surprise to many that the standard testing for urinary tract infections has a staggeringly high inaccuracy rate. For example, the dipstick tests are inaccurate 70% of the time, whereas the urine culture tests are inaccurate around 50% of the time. Yet if the go-to testing is so inaccurate why does it continue to be the most used method of detecting a UTI to this day? And why exactly are these tests so unreliable? In this blog, we will be examining the fallible world of UTI testing.
History of Current Testing
One key issue with our current state of UTI testing is that we are still reliant on data from many decades ago. The standard for diagnosing a UTI comes from a study in the 1950s by a scientist named Kass. Kass studied a small sample of pregnant women with kidney infections. Notably, none of these women had lower urinary tract infections and therefore were not a reliable basis from the get-go. Therefore, the test was never created to detect lower urinary tract symptoms.

However, the flaws with the Kass study don’t end there. The standard for diagnosing a UTI, otherwise known as the “Kass Criteria,” sets the minimum required number of bacteria per milliliter of urine at >100,000. Because of multibacterial infections, meeting this criteria is sometimes impossible. The dipstick and urine culture only test for fast-growing bacteria like E. coli, when in reality it can be many different bacteria that can be slow-growing. Today we know that UTI can be caused by low levels of multiple pathogens, but the Kass Criteria doesn’t account for that. This ends up with a test result stating that the sample is contaminated or mixed growth, thus failing the diagnostic criteria for UTI.
There is another flaw with the Kass Criteria: the fact that it reinforces the false belief that the bladder is sterile and that any results with mixed growths detected are due to contamination. However current science has long since established that the bladder is not sterile. Rather, it is home to many different types of bacteria. That the Kass Criteria is still considered the standard for UTI diagnosis 70 years after its creation proves to be a major flaw in how our medical system treats the most common outpatient infection.
Why Negative Results Happen
The most common test for diagnosing a urinary tract infection is the dipstick test. This procedure is the first step in diagnosing a UTI, but has many flaws. These tests search for obvious signs of infection, like blood, white blood cell count, or pH levels. Yet for most people living with a UTI, the dipstick test falls short and fails to detect any sign of infection. Negative results are extremely likely, with the test bearing a 70% inaccuracy rate.
Some doctors will see the negative result of the dipstick test and send the urine sample on for further testing. In these circumstances they will almost always use the urine culture test, also known as the “gold-standard” of UTI testing. There are many problems with this test, one being that urine is not sterile, so many samples will be ruled out as being “contaminated” when they are simply detecting bacteria in the urobiome. Much like the dipstick test, the urine culture method is inaccurate around 50% of the time, resulting in many people going untreated.
Another key issue with current testing is that it can only detect free-floating bacteria. Recent science has shown that UTIs can be propagated by bacteria that buries itself within the cell wall. Once the bacteria is embedded in the cell wall, it not only will not show up on standard tests but also often creates something called a “biofilm.” Biofilms are a mucus-like secretion by bacteria that covers the surface of the cell wall and acts as a barrier. This coating will hold the bacteria compactly together and prevent antibiotics from piercing through the biofilm to treat the infection. Current research estimates that around 80% of infections involve biofilms. These biofilms are extremely common, but as they circumvent testing and treatment, it is impossible to say how many UTIs go undetected and undertreated.
Lack of New Research in Testing

This leads us to one of the biggest underlying issues with the state of UTI testing: the testing methods have not evolved. Not only do healthcare workers use inaccurate tests, but in the entire field there is a lack of a standard consensus for UTI diagnosis. While advanced testing exists, the vast majority of patients will receive old testing methods. Despite the known inaccuracies of the outdated dipstick and urine culture test, these modalities are often the beginning and end of UTI diagnosis in most medical settings. As they are largely unreliable and ignore current research, this results in many patients with clear UTI symptoms not having access to the treatment they need.
The time has long since passed for new research to be done into UTI testing. But compared to other medical fields, the area of UTI research is still a emerging topic. Much research needs to be done, and while some scientists are making significant progress it is crucial that more money and time is afforded to the field of this complex condition. Until that becomes a reality, many people–especially women and those with female reproductive organs–will continue to go undiagnosed and untreated.
Conclusion and Looking Forward
It is time for us to do better. While some research has been done into new testing models–such as Nicole De Nisco’s emerging point-of-care testing that looks for inflammatory biomarkers rather than using cultures–as a medical field the science of urinary tract infections has been lingering behind. The fact that doctors are still reliant on science from 70 years ago is an utmost failure to treat what is the most common outpatient infection. That the standard of UTI care begins and ends with the faulty Kass Criteria is a foundational weakness that must be addressed sooner rather than later.
Ultimately patients must feel like they have a voice. As the best experts on their lived experiences, patients must feel able to speak up and ask questions to their doctor, ask for more advanced testing, and even present the latest research. However, even this can be a tall order to ask for many people living with UTI, who have regularly reported feeling dismissed and unheard by some doctors. The flawed system of UTI management and treatment is a multi-faceted issue, but at Let’s Talk UTI we are stepping up to bat to provide patients a voice, further education, and change the outdated system. On our website we have resources for advanced testing, questions to ask your doctor to have a more productive appointment, and even resources for doctors. Finally, we are also working with a global alliance of patient-focused organizations, named APUR, to influence and conduct research to illuminate this critical issue. We hope you will consider signing up for our email newsletter and joining us on the important mission to change the system around UTI.