Ask the doctors: ‘Silent’ UTIs present a real health threat to the elderly

Dear Doctor: Our 92-year-old mother, who’s still sharp as a tack, was perfectly fine one moment and then suddenly became weak and extremely disoriented. It was like she had dementia. We expected to hear that she had suffered a stroke, but hospital tests showed she had a UTI. Why would that affect her mind? And why didn’t she ever have any other symptoms?

Dear Reader: A urinary tract infection, or UTI, often presents differently in the elderly than in younger individuals. The typical symptoms we’re familiar with – which include a burning sensation during urination; scant urinary output despite a frequent urge to go; urine that is cloudy, dark or that smells strange; and pressure or pain in the abdomen – frequently do not show up. Instead, the first sign that an elderly person has contracted a UTI can often be what you have described – a sudden change to their well-being and demeanor. These infections can lead to serious problems, such as kidney damage or even sepsis, so “silent” UTIs present a real health threat to the elderly.

A UTI occurs when any part of the urinary system, which includes the urethra, bladder, ureters and kidneys, becomes infected with bacteria. The urethra is the duct through which urine flows from the bladder and out of the body. The ureters are the ducts that convey urine from the kidneys to the bladder. Because the urethra is shorter in women than in men, and because it is located so close to the rectum, a potential source of bacteria, UTIs tend to be more common in women than in men.

It’s possible that the reason older adults often fail to produce noticeable symptoms is that the physical changes that signal a UTI are the result of the immune system fighting off the infection. As we age, our immune systems tend to slow down, so an infection can be more advanced by the time any symptoms show up.

The first symptom that some older adults will notice is lower back pain, which happens when the infection has reached the kidneys. In post-menopausal women, changes to the urinary tract can make them more vulnerable to infection. In men, prostate issues can result in incomplete emptying of the bladder, which leaves them vulnerable to infection. As for why UTIs are associated with altered mental status in the elderly, the reasons aren’t completely clear. One theory is that the surge in inflammation, which can affect the neurotransmitters that help nerve cells to communicate, interferes with normal brain function.

A urinalysis can reveal the presence of certain compounds in the urine that suggest a UTI. A urine culture will pinpoint the specific bacterial culprit. The good news is that UTIs respond well to antibiotics. As with all antibiotic therapies, it’s vital to take the entire course that has been prescribed. In patients whose UTI had no symptoms, we also think it’s a good idea to consider a follow-up urine culture a few days after the antibiotic therapy is complete. This will confirm that the UTI has cleared up completely.