Asymptomatic Bacteriuria

What is asymptomatic bacteriuria?

Asymptomatic bacteriuria is the presence of bacteria in your urine (pee) without any symptoms. It’s found during a urinalysis or a bacterial culture.

Asymptomatic bacteriuria isn’t harmful in most people and you usually don’t need to treat it. If you’re pregnant, having a procedure or had a kidney transplant, your provider may treat you with antibiotics to reduce your risk of complications.

Is asymptomatic bacteriuria the same as a UTI?

Asymptomatic bacteriuria is similar to a urinary tract infection (UTI). They both involve having bacteria in your urinary tract — but you can have bacteria in your urine without having a UTI. Healthcare providers diagnose you with a UTI if you have symptoms (like fever, burning sensations when you pee or having an urgent need to pee frequently). You have asymptomatic bacteriuria if you don’t have symptoms.

How common is it?

Asymptomatic bacteriuria is very common and often temporary. Studies suggest that, when screened regularly, bacteria is found in the pee of:

• Up to 45% of people with a vagina (a shorter urinary tract makes you more likely to get bacterial infections).
• Up to 50% of people over 70 years old living in long-term care facilities.
• Almost all people with long-term medical devices in their urinary tract (like a Foley catheter or ureteral stent).

These bacteriuria events can be very brief, lasting as little as a single day.

What are the symptoms of asymptomatic bacteriuria?

Asymptomatic bacteriuria has no symptoms. Symptomatic bacteriuria is a urinary tract infection.

What causes asymptomatic bacteriuria?

Bacteria live naturally in our intestinal tracts (gut) and on our skin. Most people get bacteria in their urinary tracts when the bacteria move there from their poop or their skin — or someone else’s. Bacteria can move around:

• When you wipe after you poop.
• If you have a medical device in your urinary tract.
• While taking a bath.
• During sex.

What’s the most common cause?

E. coli is the most common cause of asymptomatic bacteriuria, followed by Klebsiella pneumoniae.

What are the risk factors for asymptomatic bacteriuria?

You might be at a higher risk for asymptomatic bacteriuria if you live in a long-term care facility or you have:

• A long-term Foley catheter or permanent ureteral stent.
• A spinal cord injury.
• Sickle-cell anemia.
• Diabetes.

How is asymptomatic bacteriuria diagnosed?

Healthcare providers usually diagnose asymptomatic bacteriuria with a urine culture. They typically don’t screen for bacteria in your pee if you don’t have symptoms. If your provider has ordered a bacterial culture, it might be because you’re at a higher risk for a symptomatic infection and need to be treated with antibiotics.

How is asymptomatic bacteriuria treated?

Most of the time, providers don’t treat asymptomatic bacteriuria. The risk of developing a urinary tract infection from bacteriuria is low if you don’t have symptoms. And the risk of using antibiotics — the treatment for bacterial infections — outweigh the benefits. Use of antibiotics can contribute to antibiotic resistance, development of hard-to-treat infections (like C. diff) and cause uncomfortable or even painful side effects.

When should you treat asymptomatic bacteriuria?

Providers treat asymptomatic bacteriuria under certain circumstances. These include:

• Pregnancy. Left untreated, bacteriuria during pregnancy increases the risk of preterm birth and low birth weight.
• Renal (kidney) transplant. If you’ve received a kidney transplant, bacteriuria can increase your risk of a UTI (with symptoms) and rejection of the donated kidney.
• Certain urological procedures. If you have bacteriuria during certain procedures on your urinary tract, like transurethral resection of the prostate (TURP), you might be at a higher risk for complications.

Antibiotics for asymptomatic bacteriuria

If your provider treats you for asymptomatic bacteriuria, they might use one of these antibiotics:

• Amoxicillin.
• Ampicillin.
• Cephalosporin.
• Nitrofurantoin.
• Trimethoprim-sulfamethoxazole (TMP/SMX).

Can asymptomatic bacteriuria be prevented?

Some amount of bacteria in your urinary tract is common and hard to prevent. But strategies for preventing UTIs can also help reduce your risk for asymptomatic bacteriuria. These include:

• Peeing after sex.
• Wiping front to back if you have a vagina.
• Not using douches, powders or sprays in your genital area.
• Avoiding baths (shower instead).
• Drinking plenty of water.
• Following directions to properly care for any medical devices in your urinary tract, like a catheter.

What can I expect if I have asymptomatic bacteriuria?

Your provider will only treat you with antibiotics if you have a condition or upcoming procedure that, if left untreated, puts you at a higher risk for complications. Treatment lasts five to seven days.

Outlook for asymptomatic bacteriuria in pregnancy

Treating asymptomatic bacteriuria with antibiotics can reduce your risk of certain pregnancy complications by up to 35%.

When should I see my healthcare provider?

If a provider diagnoses you with asymptomatic bacteriuria — whether you treat it or not — contact them if you start developing symptoms of an infection, like fever, urgent need to pee or pain in your abdomen. Your provider can tell you what symptoms to look out for.

What questions should I ask my doctor?

It might be helpful to ask your healthcare provider:

• Do I need to treat bacteriuria if I have no symptoms?
• What symptoms should I look out for?
• How do I take my medication?
• When should I follow up with you?

A note from Cleveland Clinic

Sometimes, test results sound more alarming than they need to be. Having bacteria in your pee is common and doesn’t mean you’ll get a UTI. But if you’re pregnant, having a procedure or had a kidney transplant, it’s important to get antibiotic treatment to avoid complications.