The “gold standard” test for urinary tract infections (UTIs) is not fit for purpose, according to research which suggests that it fails to diagnose most chronic sufferers.
UTIs afflict an estimated 150-200 million people around the world every year. While many, particularly young women, suffer acute attacks of cystitis, which is quickly resolved with a few days of antibiotics, chronic infection can stay with people for many years and wreak havoc with their lives.
Those who suffer most tend to be older women, who may be sent home time and again by the doctor because the UTI test is negative. But the test, which has been around since the 1950s and was adopted all over the world, is flawed, says Dr Jennifer Rohn, head of Urological Biology at University College London’s (UCL’s) Department of Renal Medicine in the Division of Medicine at the Royal Free Hospital.
Her team compared the results of the standard test – the midstream urine culture (MSU) – with DNA sequencing for 33 new patients with symptoms, 30 who were experiencing a relapse after having been treated and 29 controls with no symptoms. Their research, published in the Journal of Clinical Microbiology, found only six of the MSU tests were positive, while the DNA test identified infection in all the patients with symptoms.
“This work put the MSU head-to-head with modern DNA analysis methods – and it failed spectacularly,” said Rohn. “On the other hand, genomic sequencing using enriched urine specimens easily managed to pick out people who were genuinely ill.
“This paper shows that the MSU is unsuitable for excluding UTI in patients with lower urinary tract symptoms. Therefore, we urgently need to develop alternative rapid diagnostic tests to take its place.”
“For decades patients suffering appalling symptoms have been betrayed by a urine test that isn’t fit for purpose,” said UCL Professor Emeritus James Malone-Lee, a consultant physician in London who treats many chronic UTI patients, and one of the authors on the paper.
“All too often, those afflicted are spurned by health carers who are duped by this test. This new study proves that the gold standard test, used throughout the healthcare system, is a hopeless dud incapable of distinguishing infected patients from normal controls.”
Rohn said the test has been under suspicion for some time. “We’ve had inklings of this for years,” she said. “This really proves it for the first time.”
UTI was not just about a young woman who has an acute infection that resolves with a few days of antibiotics, she said. “It’s a huge concern especially in the elderly, but also people with spinal injuries, multiple sclerosis, pregnant women, renal transplant patients, in-patients in hospitals – UTIs are a huge problem. These more vulnerable subsets are not the kind of people who get a one-off UTI.”
It would be great if the paper convinced everyone, Rohn said, “but there is a lot of conservative thinking in medicine and it’s hard to change prevailing views about things like this.” There was also embarrassment and some stigma about UTIs, she said.
“I feel like it’s been neglected in medicine because these people have been neglected. It’s really sad. People tell these same stories – I’m begging for antibiotics, I’ve had symptoms for 10 years but the computer says no. The test is negative. I feel it’s a moral issue in a way – that patients are getting a bad deal.”
Carolyn Andrew from CUTIC (chronic urinary tract infection campaign) said the condition could be very painful and ruin lives, even making some feel suicidal. “We have people in our group who have had to give up work because of this, some who are struggling to bring up families. We have children from the age of eight to 13 or 14 who are not able to go to school,” she said.
“Some people have to live on benefits. They can’t have a sex life because it is too painful and there is mental stress as well. We have dozens of women who have ended up with sepsis in hospital because it can travel to the kidneys. We have people who can’t get diagnosed and are absolutely devastated.”
The treatment for a UTI is antibiotics, but people who suffer recurrent infections end up with resistant strains. The World Health Organisation has found that up to 65% of UTIs caused by the bacterium Escherichia coli are resistant to ciprofloxacin, the antibiotic used to treat them.