The utility of polymerase chain reaction testing for urinary tract infections

Laboratorians and those of us who support the clinical laboratory space know that standard urine culture (SUC) has for decades been the “gold standard” for identifying pathogens causing urinary tract infections (UTIs) and informing UTI treatment therapies. Not only has urine culture testing provided reliable results, but providers and patients have become familiar and comfortable with culture-based UTI testing processes from sample collection to understanding results — adding an important level of trust around the process. However, over the years, known limitations of SUC and emerging patient priorities have spurred innovation in UTI testing.  As with diagnostic testing for respiratory, bloodstream, sexually transmitted, gastrointestinal and other infections, providers are looking to molecular testing — more specifically polymerase chain reaction (PCR) testing for UTIs — to address concerns like speed to treatment and proper antibiotic management.

UTI prevalence in the United States

Urinary tract infections remain one of the most common bacterial infections affecting individuals in the United States. Reports indicate that 33% to 60% of women in the U.S. will develop at least one UTI in their lifetime, with a double-digit percentage of those diagnosed experiencing recurrent infection at some point. At least 12% of men will have a UTI in their lifetime. Furthermore, the Urology Care Foundation puts the number of UTI-related physician office visits in the U.S. each year to be around eight million.

A good percentage of UTIs that are timely and accurately diagnosed are responsive to empiric or personalized therapies. At the same time, other data indicates that UTIs that spread beyond the liver and kidneys create complications that translate into 626,000 or 1.8% of all hospital admissions each year.¹ Untreated or misdiagnosed UTIs can lead to chronic pain and recurrent symptoms, reduced quality of life issues, damage to vital organs, sepsis, and other life-threatening infections.

Older adults and the elderly continue to make up a sizable portion of the patient population being diagnosed with a UTI, mirroring longstanding data that shows that UTI occurrences increase with age. Lifestyle, care needs, and health conditions generally associated with the regular aging process — such as hormonal changes, weakened immune systems and other co-morbidities — make older adults more susceptible to UTI. 

One notable observation related to delivery of UTI testing is the shifting preferences in where patients present to be tested.  Following rising demand for molecular testing for respiratory, sexually transmitted,² and other common infections at urgent care centers (demand growing prior to and then fueled by the pandemic), patients suffering with UTI-like symptoms, who are unable or unwilling to wait to for an office appointment, are now expecting urgent care centers to provide reliable, on-demand UTI testing and treatment.

Culture-based and PCR testing for UTI

Increased education around the importance of early detection and risks of complications, an aging population, and prevalence of UTIs all contribute to the growth in volume of UTI testing and diagnoses cases in the United States.³  With increases in cases and testing, comes the necessity among providers to balance emerging patient priorities and concerns with long-standing best practices for UTI testing. An overarching challenge in UTI testing has become how to deliver accurate UTI testing, while addressing patient expectations around immediate symptom relief, expedient and accurate identification of UTI, and antibiotic stewardship.

In the United States, SUC is the most commonly used test for UTI. Culture-based platforms have been comparatively reliable at identifying pathogens causing infection and providing antimicrobial susceptibility data to inform treatment. But, as we are hearing from laboratorians, more and more providers are looking to PCR-based testing solutions to complement or improve on culture-based platforms, with regard to the following:

1)    Speed – UTIs can become more complicated just by letting time elapse. Many patients are looking for relief from symptoms present at the time of testing — symptoms that can be similar to those of other infections — or they worry about progression of infection. 

PCR testing is successfully demonstrating its ability to provide accurate insights into the bacteria causing the infection within hours, versus the days or even weeks required for traditional testing.  

2)    Standardization – PCR testing is more standardized in labs, creating efficiency and consistency in labs.

3)    Sensitivity and specificity –  PCR testing reliably identifies fastidious, atypical, or uncommon pathogens and differentiates between types of pathogens in samples, helping to lower the probability for false negatives and false positives. As importantly, improvements in UTI testing around speed, sensitivity, and standardization speak to current healthcare concerns about effective antibiotic management, as the practice of beginning broad spectrum antimicrobial therapy before UTI results are available is being called into question. PCR continues to demonstrate value in this regard, by being able to more quickly confirm single and multiple causative pathogens — independent of culture-related errors like low bacterial load, poor growing environment, or imperfect sample collection — and inform the most effective treatment.

Feasibility of PCR testing

The feasibility of integrating PCR to complement or enhance UTI testing capabilities typically prompts provider examination and conversation around the following:

Staffing –  Running PCR tests may not require lab team members to have the higher level of education and experience that is necessary for proper SUC set up and analysis.

Costs – Technological advancements have made molecular testing equipment and consumables, including PCR, more affordable and accessible without sacrificing (and in some cases, improving) the accuracy of results. PCR testing for UTIs has become a realistic and wise investment for providers and facilities — even those with moderate testing volume — when just a few years ago this technology would be out of reach. Reliability of PCR results also saves dollars on confirmation tests and reflex testing, as well as saves valuable lab tech time spent on UTI testing and analysis of results.

Reimbursements and financial impact – While reimbursement programs vary among states and payors for UTI testing, recent information shows that molecular testing, in general, is more commonly being reimbursed at higher rates against traditional methods. 

Patient populations served – From the relationships we have across the continuum of care, we know that urgent care centers as well as providers involved with the care of the elderly and older Americans are seeing the utility of PCR testing in their labs. More physician offices (particularly in women’s health, sexual health, and immunology), emergency departments, and reference labs are inquiring about options for bringing PCR testing for UTIs into their practices.

Space and Infrastructure – PCR UTI testing equipment can work in facilities of all sizes, as the footprint required to run the technology can operate on floor or counter space.

Conclusion

Emerging patient priorities as well as limitations with traditional culture-based testing are driving innovation in UTI testing – leading to today’s growing interest in options for adding PCR testing to labs across the United States. While PCR has proved to be a platform that is improving efficiency in the laboratory, and in some cases is even profitable, providers themselves should determine utility of PCR testing in their businesses. Suppliers, industry experts, and healthcare associations can help evaluate the feasibility of adding PCR capabilities to your offering.

As patient expectations for convenience and quality care continues to increase, healthcare providers need to keep pace. Optimizing laboratory diagnostic services is one of the areas that can have a direct and lasting impact on a lab’s outcomes and growth.

REFERENCES

1.    Medina M, Castillo-Pino E. An introduction to the epidemiology and burden of urinary tract infections. Ther Adv Urol. 2019;11:1756287219832172. doi:10.1177/1756287219832172.

2.    Pearson WS, Tao G, Kroeger K, Peterman TA. Increase in Urgent Care Center Visits for Sexually Transmitted Infections, United States, 2010-2014. Emerg Infect Dis. 2017;23(2):367-369. doi:10.3201/eid2302.161707.

3.    Urinary tract infection testing market size, share & trends analysis report by type (urethritis, cystitis, pyelonephritis), by end use (reference laboratories, general practitioners, urologists, urgent care), by region, and segment forecasts, 2023 - 2030. Grandviewresearch.com. Accessed January 24, 2025. https://www.grandviewresearch.com/industry-analysis/urinary-tract-infection-testing-market-report.