Contaminated Food Can Cause Some UTIs. Here’s How to Reduce Risk. - The New York Times

Certain strains of E. coli, a bacteria commonly associated with food poisoning, can lead to painful urinary infections.

Scientists are pointing to a surprising cause of some urinary tract infections: E. coli bacteria in meat. A new study used statistical modeling to estimate that E. coli, commonly known as the bacteria behind many food-borne illnesses, may cause hundreds of thousands of U.T.I.s in the United States annually — likely a small fraction of overall U.T.I.s, but enough to intrigue, and in some cases concern, experts.

The new study looked at chicken, turkey and pork in particular, as previous studies suggested that these foods can become contaminated with the type of E. coli that could induce a U.T.I. Over the last two decades, scientists have increasingly viewed food as a potential source of infection; the new study highlights just how pervasive these food-borne U.T.I.s may be.

A U.T.I. occurs when bacteria enters the urethra and infects the urinary tract. Sometimes an infection develops because of poor hygiene (i.e., not wiping correctly) or from sex, and some people are more anatomically or genetically prone to develop an infection than others. U.T.I.s can be pernicious and painful. People may experience symptoms like discomfort when urinating or a frequent need to urinate; they may feel cramps, fatigue or a stinging sensation during sex. Some may have "urinary hesitancy," said Dr. Monica Woll Rosen, an OB-GYN at the University of Michigan Medical School — the urge to urinate that doesn't produce any urine. U.T.I.s occur in both men and women, but they are more common in women because females have shorter urethras.

The symptoms of a U.T.I. are likely to be the same no matter the source of the infection, Dr. Rosen said. While the vast majority of U.T.I. infections are mild and treatable, in rare cases U.T.I.s can be severe, and even fatal, which is why researchers are so motivated to track down their causes.

How can food cause a U.T.I.?

A food-borne U.T.I. starts the way most U.T.I.s do: when E. coli from the gut migrates from the anus to the urethra, said Lance B. Price, a professor of environmental and occupational health at George Washington University and one of the authors of the new study.

Most of us carry E. coli around in our guts most of the time, said Dr. James R. Johnson, an infectious disease professor and leading researcher on urinary tract infections at the University of Minnesota and an author of the study. E. coli can contaminate food, but humans and animals can also carry and transmit the bacteria to one another. For the most part, this bacteria won't bother us; only specific E. coli strains have the capacity to colonize the urinary tract and cause U.T.I.s. "As long as they stay where they belong in the gut, everybody's happy," Dr. Johnson said. "It's only when they get confused and go somewhere that they shouldn't be that trouble can happen."

Other foods, including plants, can potentially harbor the E. coli that causes U.T.I.s, but those strains seem to be more commonly found in meats than in other foods, Dr. Price said.

There's no way to determine the source of a U.T.I. based on symptoms, although you're far more likely to get infected from a nonfood source of E. coli than from food-borne E. coli, Dr. Johnson said. And other bacteria can also cause U.T.I.s.

How to reduce your risk of getting a U.T.I. from food

The findings from this study don't mean you should immediately change your eating habits, said Dr. Michelle Van Kuiken, a urologist at the University of California, San Francisco. "There's not a one-to-one correlation" between eating meat and U.T.I.s., she said, adding that she sees plenty of patients with recurrent U.T.I.s who are vegetarians and vegans. But further research might illuminate how diet can impact the risk of infection.

The recent findings should remind people to double down on preventive measures when cooking meat, Dr. Price said. That means being mindful not just when you handle raw meat itself but also when you interact with the packaging — especially the potentially bacteria-laden juices in a raw chicken container, for example.

The Centers for Disease Control and Prevention recommends that people take basic steps to safely prepare food and prevent potential E. coli exposure, including washing hands before, during and after cooking; using separate cutting boards for raw meats and other items like produce; ensuring that meats are cooked to the appropriate temperature; and refrigerating foods properly.

While it may seem counterintuitive to associate kitchen hygiene with U.T.I. prevention, Dr. Johnson said that the emerging research on food-borne E. coli shows that taking these steps could potentially ward off infection, just the way urinating after sex, staying hydrated and properly wiping might.

"Most people don't really understand how U.T.I.s happen," he said. "They just happen."