Ask the Expert: Urinary Tract Infections and Asymptomatic Bacteruria

Catherine DuBeau

Catherine E. DuBeau, MD
Professor of Medicine
Professor of Obstetrics and Gynecology
Dartmouth Geisel School of Medicine

Q:  What is a urinary tract infection (UTI) and what causes it?

A:  A UTI is an infection in your urinary tract (UT). Your UT includes your kidneys, bladder, and the tubes that connect them. Your urinary tract makes urine and eliminates it from your body.

Most UTIs develop when bacteria – usually from your feces -- enter your bladder. This can cause a bladder infection. If the bacteria spread farther up through the urinary tract to your kidneys, they can cause a kidney infection. Kidney infections can sometimes cause serious illnesses that require treatment with intravenous antibiotics.

Q:  As you get older are you more likely to have UTIs? Can anything else increase your risk of getting UTIs?

A:  The odds of getting a UTI increase with age, especially in women. In fact, UTIs are one of the most common infections among older adults.

UTIs are also more common among people who:

  • Have diabetes
  • Have problems with bladder control and leak urine
  • Have kidney stones, an enlarged prostate gland, or other health problem that can block the flow of urine through your urinary tract
  • Live in a nursing home

Q: What symptoms do UTIs cause in older adults?

A:  Symptoms of UTIs in older adults can include:

  • Pain or burning when you urinate
  • Pain on one side of your back, below your ribs (where your kidneys are)
  • Feeling as though you have to urinate often, even though little urine comes out when you try
  • Urine that is cloudy or smells bad
  • Fever, nausea, or vomiting

You should let your healthcare provider know if you have any of these symptoms. They will discuss with you whether your symptoms might be caused by a UTI and decide how to treat it. A UTI is usually treated with antibiotics. Some older persons may become more confused when they get a UTI.  However, confusion by itself does not mean a UTI is present – other symptoms like pain or burning with urination or more frequent urination or leakage should be present as well.

Q:   What is “asymptomatic bacteriuria”?

A:  Asymptomatic bacteriuria is when you have bacteria in your urinary tract but you don’t have the symptoms that usually go along with UTIs.

Older adults are more likely than young people to have asymptomatic bacteriuria. People who have a urinary catheter – a small tube that is inserted into the bladder to drain it— also have an increased risk of having asymptomatic bacteriuria.

Q:  How is asymptomatic bacteriuria treated?

A:  Most people with asymptomatic bacteriuria don’t need treatment because the bacteria don’t usually cause any harm.

The following people with asymptomatic bacteriuria may run an increased risk of developing kidney infections:

  • People who have had kidney transplants
  • People with diabetes
  • People with infected kidney stones

These people only need treatment if they actually have symptoms of a UTI.   If symptoms are present, the healthcare provider can analyze the urine and consider a “culture” to check for bacteria in the urinary tract. If the assessment indicates an infection, they should prescribe an appropriate antibiotic.

Q: Why not regularly check all older people for bacteria in the urinary tract, and then treat the bacteria if it’s found? It seems that this wouldn’t hurt, and could help -- by killing the bacteria and preventing kidney infections.

A:  Many studies have found that prescribing antibiotics for people without UTI symptoms offers no benefits in women or men. In fact, in these cases, antibiotics have been linked to other medical problems, including a serious type of diarrhea called C. difficile.  Treating people with antibiotics when there is no evidence that they have a bacterial infection can also lead to “drug resistance.”  Drug resistance is a process in which antibiotics lose their effectiveness to fight bacteria.

The important thing for healthcare providers to do is carefully determine whether or not an older patient is truly symptom-free therefore and has asymptomatic bacteriuria. If the patient has symptoms of a UTI, the healthcare provider should prescribe an antibiotic.

Q:   Are there any circumstances in which a healthcare provider should give antibiotics to a patient who clearly has asymptomatic bacteriuria and not a UTI?

A:   Yes. If a patient is going to have urinary tract surgery, they should be treated with antibiotics beforehand, to prevent infections and complications that might develop during or soon after the surgery.


Last Updated September 2019

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