Antibiotics affect the human microbiome, wiping out the protective microbes in the gastrointestinal tract and increasing people’s vulnerability to C. difficile, which the Centers for Disease Control and Prevention has called an “urgent threat.”
In the Michigan hospital study, patients treated for asymptomatic bacteriuria fared no better on a variety of measures than those who weren’t treated. “But they stayed in the hospital a day longer,” said Dr. Lindsay Petty, the study’s lead author and an infectious disease specialist at the University of Michigan.
She theorized that their doctors were awaiting urine culture results. The patients, meanwhile, faced additional risks of disrupted sleep, infections, physical deconditioning from time spent in bed and other hazards, while generating needlessly higher hospital bills.
Beyond its effect on individuals, “antibiotic resistance is one of the greatest public health crises of our time,” Dr. Petty said. When bacteria develop resistance to overused drugs, doctors are left with fewer and riskier weapons with which to fight infections.
Because U.T.I.s occur so commonly — 40 percent to 60 percent of women, in whom they’re far more common than in men, will experience at least one in their lifetimes — it’s easy for doctors and patients to engage in so-called scapegoating, blaming a supposed U.T.I. for problems that may have little to do with the urinary tract.
In older patients, particularly, confusion and hospital delirium can lead family members to urge doctors to order urine cultures, especially when dementia makes it difficult for patients to describe their symptoms.
But “the idea of attributing delirium to a U.T.I. is losing ground,” Dr. Wald said. When older patients grow confused, “maybe they’re dehydrated,” she said. “Maybe it’s a new medication.” Hospitalization itself might be to blame.