Up to half of UTI diagnoses may be false, study finds

STIs, meanwhile, are going undetected


Up to half of women diagnosed with a urinary tract infection might not actually have one, according to a new study in the Journal of Clinical Microbiology—and more than a third of them might have sexually transmitted infections that go undetected.

When a woman goes to the emergency room complaining of symptoms like frequent urination or abdominal pain, medical staff will typically administer a dipstick urine test, a quick diagnostic tool that can be read in just a minute or two. “If that test is abnormal, people assume the patient has a UTI,” Michelle Hecker, the lead author of the study, explained to Women in the World in a phone interview. “But it’s a myth.” A host of other conditions, including STIs, chemical irritants and atrophic vaginitis can cause symptoms similar as a UTI as well as an abnormal reading on a dipstick urine test.

For a period of two months, Hecker, an infectious disease specialist and assistant professor at Case Western Reserve University in Ohio, and three of her colleagues tracked every instance in which a woman between the ages of 18 and 65 presented at the emergency room of an urban hospital in Cleveland with “genitourinary symptoms” like pain during urination. They ended up with a sample of 264 such women.

In each of these cases, hospital staff administered a disptick urine test. The urine sample is typically saved for 24 hours, and Hecker and her team were able to retrieve each sample and conduct their own tests, including a urine culture—a more intensive and conclusive test for UTIs, in which urine is analyzed in the lab (results can take a few days)—and tests for three common STIs: gonorrhea, chlamydia and trichomoniasis.

Her conclusions were very different from those of the hospital. “We found that anywhere from 40 to 50 percent of women who were diagnosed with a UTI did not have a positive urine culture,” Hecker said. Meanwhile, 37 percent of the women in her sample did test positive for an STI, but hadn’t been diagnosed in the hospital. (The most common missed diagnosis was chlamydia, followed closely by trichomoniasis.) That means a significant number of women are not only missing out on getting treatment for potentially serious infections, putting themselves at risk for infertility, pelvic inflammatory disease and other complications; they’re also being prescribed unnecessary antibiotics.

Hecker calls UTIs “the most common reason people get antibiotics they don’t need.” Whenever a patient goes on antibiotics, she risks suffering side effects like rashes, allergic reactions and antibiotic-associated infections like clostridium difficile and yeast infections.

On a population level, the risks are even more dire. “The more antibiotics we give, the more antibiotic resistance we see in the community,” said Hecker; if resistance grows, we could end up lacking an effective treatment for people who need it. “The rapid [dipstick] test should not be done as often as it is,” Hecker said. “It leads to wrong conclusions. We need to do more definitive testing.”

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