Q: An older friend, who is in her 90s, has been having bacteria in her urine, but no symptoms. Despite treatment with antibiotics, she was still having bacteria in the urine, so the doctor recommended chronic antibiotics and a referral to urology.
What can be done when an elderly woman has bacteria in her urine but no symptoms? Can a urology consultation help?
A: This is a great question. People often think that your friend is having a “recurring urinary tract infection (UTI)” or even a chronic UTI. But actually, you are describing something called asymptomatic bacteriuria, which means having urine bacteria without symptoms.
Every older person and family caregiver should know about asymptomatic bacteriuria. Here’s why:
- It’s very common in older adults. This condition is found in an estimated 20% of women aged 80 or older, and also affects older men. The older the person, the more common it is. Asymptomatic bacteriuria is even more common in nursing homes, where it’s estimated to affect 30-50% of residents.
- It’s often confused with a urinary tract infection (UTI). This can lead to unnecessary — and potentially harmful — treatment with antibiotics.
- It usually does NOT need to be treated with antibiotics. As I’ll explain below, research shows that people don’t live better or longer when asymptomatic bacteriuria is treated. In fact, such treatment can be harmful: one study found that treatment increased the risk of future (real) UTIs, and increased the risk of infection with antibiotic-resistant bacteria.
- It’s common for older adults to inappropriately be given antibiotics to treat this condition. Part of why this happens is that distinguishing this condition from a real UTI cannot just be done with a urine test. Instead, health providers must take the time to talk to the patient — or family caregiver — and ask about whether symptoms are present. In a busy clinical environment, this step is all-too-often neglected.
In short, this is another one of those common aging health issues that can easily be mismanaged, unless older adults and family caregivers know to ask extra questions.
Because it’s so common for antibiotics to be inappropriately prescribed for this condition, “Don’t treat asymptomatic bacteriuria with antibiotics” is the number one “Choosing Wisely” recommendation from the Infectious Disease Society of America. The American Geriatrics Society also includes this recommendation on its Choosing Wisely list.
Now, let’s try to equip you to understand this common condition. This will help you — and your older loved ones — avoid unnecessary testing and antibiotic treatment. Specifically, in this article I’ll cover:
- What is asymptomatic bacteriuria?
- How common is asymptomatic bacteriuria?
- How to tell the difference between asymptomatic bacteriuria and a UTI
- Why asymptomatic bacteriuria usually doesn’t warrant antibiotics
I’ll close with some practical tips for older adults and family caregivers concerned about UTIs and/or bacteria in the urine.
What is asymptomatic bacteriuria?
Asymptomatic bacteriuria means having significant quantities of bacteria in the urine, but no clinical signs of inflammation or infection.
In other words, in asymptomatic bacteriuria, a urine culture will be positive. (This means that if your healthcare provider takes a sample of urine and a clinical laboratory incubates it, within 1-2 days, a sizeable quantity of bacteria will grow.)
When bacteria are present in the bladder but not provoking an inflammatory reaction, this can also be called bacterial “colonization” of the bladder.
How common is asymptomatic bacteriuria?
Asymptomatic bacteriuria is more common in older adults than many people — including practicing clinicians — may realize:
- In women aged 80 or older, 20% or more may have this condition.
- In healthy men aged 75 or older, 6-15% have been found to have bacteria with no UTI symptoms.
- Studies of nursing home residents have found that up to 50% may have asymptomatic bacteriuria.
This condition also affects 2-7% of premenopausal women, and is more common in people with diabetes.
Asymptomatic bacteriuria becomes more common as people get older, in part because it is related to changes in the immune system, which tends to become less vigorous as people age or become frailer.
Studies have found that in older adults, asymptomatic bacteriuria does sometimes go away on its own, but it also often comes back or persists.
How to tell the difference between asymptomatic bacteriuria and a UTI
By definition, in asymptomatic bacteriuria, there should be no UTI symptoms present.
The following signs and symptoms can be caused by UTI:
- Burning or pain with urination
- Increased frequency or urgency of urination
- Bloody urine
- Pain in the low abdomen, flank, or even back
- Fever
(What about “cloudy” or “foul-smelling” urine? In the absence of other symptoms, no study has shown that this is a good way to detect a possible UTI. See here: Cloudy, Foul-Smelling Urine Not a Criteria for Diagnosis of Urinary Tract Infection in Older Adults.”)
Whether or not an older person has a clinical UTI, the urine dipstick may be abnormal, in part because certain abnormal results suggestive of UTI may in fact only reflect bacterial colonization of the bladder. So one should not rely on urine dipsticks or related urine analysis tests (which measure the number of white blood cells in the urine, among other things) as the sole justification for diagnosing a UTI. Symptoms are necessary!
The thing is, some older adults may only show vague or non-specific symptoms when they get a UTI, such as confusion or weakness. (That “confusion” would be delirium.) This is especially true of aging adults who are frail, or are quite old, or have Alzheimer’s or another dementia.
For this reason, it can be difficult to determine whether a frail or cognitively impaired older person is having UTI symptoms that warrant treatment.
Experts have debated whether it’s justified to treat for possible UTI, for those cases in which an older person with asymptomatic bacteriuria shows signs of delirium, but no other UTI symptoms.
Why asymptomatic bacteriuria usually doesn’t warrant antibiotics
Clinical studies overwhelmingly find that in most people, treating asymptomatic bacteriuria with antibiotics does not improve health outcomes. Even when it comes to the nursing home population, which is frailer than the general population, a 2022 systematic review found that antibiotic treatment of asymptomatic bacteriuria didn’t improve outcomes.
(The exceptions: pregnant women and men about to undergo urological procedures do benefit from screening for and treatment of asymptomatic bacteriuria.)
A 2015 clinical research study found that treatment of asymptomatic bacteriuria in women was associated with a much higher chance of developing a UTI later on, and that these UTIs were more likely to involve antibiotic-resistant bacteria.
Even when it comes to the nursing home population, which is frailer than the general population, a 2022 systematic review found that antibiotic treatment of asymptomatic bacteriuria didn’t improve outcomes.
Despite the expert consensus that this condition doesn’t warrant antibiotics, inappropriate treatment remains very common. A 2014 review article on this topic noted overtreatment rates of up to 83% in nursing homes. To combat this issue, this 2023 BMJ article outlines an approach nursing homes can take: Reducing unnecessary urine culture testing in residents of long term care facilities.
Is there a role for cranberry to treat or manage urine bacteria?
The use of cranberry juice or extract to prevent UTIs has been promoted by certain advocates over the years, and many patients do prefer a “natural” approach when one is possible.
However, top quality clinical research has not been able to prove that cranberry is effective for this purpose. In a 2016 study of older women in nursing homes, half were given cranberry capsules daily. But this made no difference in the amount of bacteria or white blood cells in their urine.
In a related editorial titled “Cranberry for the Prevention of Urinary Tract Infection? Time to Move On,” which summarized many other studies of cranberry for the prevention of UTI, the author concluded:
The evidence is convincing that cranberry products should not be recommended as a medical intervention for the prevention of UTI. A person may, of course, choose to use cranberry juice or capsules for whatever reason she or he wishes. However, clinicians should not be promoting cranberry use by suggesting that there is proven, or even possible, benefit. Clinicians who encourage such use are doing their patients a disservice.”
A 2012 systematic review of high-quality research studies of cranberry for UTI prevention also concluded that cranberry products did not appear to be effective.
That said, many people really feel that cranberry supplements make a difference.
As cranberry is unlikely to cause harm to older adults, I don’t object when an older person or family caregiver wants to use them. But I don’t particularly encourage it either.
Practical tips on urine bacteria and possible UTIs in older adults
Given all this, what should you do if you are worried about bacteria in the urine, or a possible UTI?
Here are my tips for older adults and families:
- Realize that asymptomatic bacteriuria is common in older adults.
- If you keep having positive urine cultures despite feeling fine, you may have asymptomatic bacteriuria.
- Know that treatment of asymptomatic bacteriuria is not going to help, and might lead to harm.
- Unless you are having symptoms, it’s pointless to try to “eradicate” bacteria from the bladder. Studies show that this increases your risk of getting a real UTI later on, and that you’ll be more likely to be infected with bacteria that are resistant to antibiotics.
- Antibiotic treatment also affects the “good bacteria” in your gut and elsewhere in the body. Research to help us understand the role of the body’s usual bacteria (the “microbiota”) is ongoing, but suggests there can be real downsides to disrupting the body’s bacteria. So you don’t want to use antibiotics unless there’s a good reason to do so.
- Avoid getting a urine culture unless you’re experiencing symptoms of likely UTI, such as pain with urination or low belly pain.
- Some healthcare providers will do a urine culture “just to check” for UTI. Or sometimes patients and family members request this. But this is a bad idea, since all you might do is uncover signs of asymptomatic bacteriuria (which then has a tendency to be inappropriately treated with antibiotics).
- Experts strongly recommend that urine tests for possible UTI only be done if an older person is experiencing symptoms.
- If a health provider suggests a urine test and you aren’t having UTI symptoms, inquire as to the purpose of the test.
If you’re caring for an older adult who has dementia or is otherwise prone to delirium:
- Realize that it can be tricky to determine whether the person is experiencing UTI symptoms.
- The doctors should still attempt to do so before checking a urine culture or treating any bacteria found in the urine. Specific symptoms to check for include dysuria (painful urination), fever, and lower belly pain.
- Realize that some experts believe that increased confusion alone (meaning no fever or other signs of UTI) may not be a good reason to treat a nursing home resident for a presumed UTI.
- A geriatrician explains this debate in this very interesting article: “Urinary Tract Infection”—Requiem for a Heavyweight
In short: I’d summarize the benefits and burdens of treating asymptomatic bacteriuria in a 90-year-old woman as follows:
Benefits: No proven benefit to antibiotic treatment in someone who doesn’t have clinical signs of a UTI.
Burdens: Antibiotics cost money, and increase pill burden. There is a risk of side-effects, of interactions with other medications, of harming your body’s “good bacteria,” and of developing an infection resistant to antibiotics. Also, the overuse of antibiotics in society means we are developing more resistant bugs all around us.
So there you have it. If an older person has a positive urine culture but no symptoms, think long and hard before agreeing to treatment. And ask extra questions before spending time pursuing a urology consultation.
Remember, bacteria in the urine does NOT equal a UTI.
So, ask your clinicians if this could be asymptomatic bacteriuria. Tell them you’ve heard that the Infectious Disease Society of America, the American Geriatrics Society, and other experts say that this condition should not be treated in older adults. (Unless you’re about to undergo a urological procedure.)
You can even share these peer-reviewed articles:
- Reducing unnecessary urine culture testing in residents of long term care facilities
- Approach to a Positive Urine Culture in a Patient Without Urinary Symptoms
- Diagnosis and Management of Urinary Tract Infection in Older Adults
- “Urinary Tract Infection”—Requiem for a Heavyweight
This article was first published in 2015. It was reviewed and updated by Dr. Kernisan in February 2024. (The basics about asymptomatic bacteriuria and UTIs in aging adults don’t change much!)
Carol Factor says
I’m a 76 year old active woman. I got a call today from my pain treatment doctor that did a urine test 3 weeks ago saying the test showed bacteria in my urine. They’re calling in an antibiotic. I absolutely detest taking those things. I have no symptoms at all. Should I go see my primary care doctor in a week or two and have him repeat the urine test? I’ve decided not to take the antibiotic the pain doctor is calling in. They said it was Microstantin? I think that’s what they said. I see the pain doctor for nerve pain in my left leg, a totally unrelated thing. The urine tests are probably to make sure you’re not on some kind of drugs? I really don’t know and should have asked. Is it a dangerous thing for me to not take the antibiotics? Thanks for your help.
Leslie Kernisan, MD MPH says
If you weren’t having symptoms, then this probably is not a clinically significant UTI and it’s FAR more likely that it was contamination or asymptomatic bacteriuria. As per the article, this doesn’t require treatments with antibiotics. You could get your urine checked again just to see if you are still growing bacteria, but honestly, I’m not sure it’s that important to check this.
I would say you are right to be cautious about antibiotics. They can do amazing things when you have a raging infection, but otherwise, it’s often a good idea to just let the body do its work, because antibiotics do have side-effects and chronic overuse is leading to a lot of resistance. Good luck!
sharon c stern says
I am a 73 ya old female with MS, and a neurogenic bladder. I have to be cathed 7 times a day. Since May 31st 2018, I have had 20 UTI’s,14 of which have been citrobacter F, which has now become drug resistant. I have UTI symptoms today, and my dipstick is positive again. Last uti was july 10th. I am going to John Hopkins in August to see if they have any idea how to treat me.. I am so frustrated, and amazed that I don’t have c-diff, but I take Florastor every day. What happens when there is no longer a treatment for this bacteria? I am so worried and upset. What would happen if I just stopped treating them? I have burning and some flank pain, but no fever.So happy I stumbled upon your excellent article!
Leslie Kernisan, MD MPH says
Sorry to hear about these issues, I can see why you’d be worried. Your medical situation definitely sounds more complicated than most, so I think it’s good that you are going to see the specialists at John Hopkins. You may want to ask them what would happen if you stopped treating the UTIs with antibiotics…my guess is that to a certain extent, the answer depends on your underlying health and your body’s ability to clear the infection on its own.
good luck!
Dan says
Thank you for your fantastic work and public service!
FOLKS, this is the best, most comprehensive blog or article on this topic that I’ve ever read (and I’ve read too many).
You neatly synthesized all the info while explaining clearly and in detail in a way that we laymen can understand and make informed decisions.
My mother suffered recurring UTIs. To the point that, at age 86, she was rushed by ambulance to the hosp.
“THIS IS A STROKE”, said the EMTs and the ER dr. She had a droopy side of face, couldn’t walk, or speak well and had reverted to her first language from 80 years ago.
Tests showed it was NOT a stroke. They were ready to discharge her.
How can you discharge someone where something is clearly very wrong, we asked? Could it be a UTI?
So they tested her.
IT WAS a UTI.
After IV antibiotics in the hospital, it took weeks of rehab to recover from, just as if it was a stroke.
She often tested negative for a UTI, so samples were taken by catheter. A low grade infection was enough to affect her. We had to watch for symptoms of sleeping all day, fist-clenched anger ( was not like her and disappeared with antibiotics) , rigidity, or sudden “lala land” dementia which came and went with treatment.
She had Normal Pressure Hydrocephalus (NPH) treated with a shunt. So she did have mild dementia but was often very sharp, unless she had a UTI. However, each diagnosed UTI seemed to leave her declining over time.
After she began permanent treatment with a daily low-dose antibiotic, and we, the family, put her on daily live liquid probiotics, she never had a severe UTI, nor even caught a single cold or flu like her family and caregivers did, for the remaining two years of her life.
So our experience was a good one.
Leslie Kernisan, MD MPH says
Thanks for your comment, I’m so glad you found the article helpful. I’m glad things worked out with your mother.
Marymaryannakb says
I keep reading need to show symptoms of UTI …..what degree of fever would be significant in a 93 year old man
Leslie Kernisan, MD MPH says
Frail older adults often have a weaker fever response, and may not have fever even when they’re experiencing a serious infection. In frail older adults, a single temp reading of 100 degrees F or persisting temp of 99 can be considered significant.
It can be hard to determine whether a frail person in their 90s is experiencing clinical symptoms of infection, especially if they have dementia; it can be hard to tell whether it’s an infection versus just a tired day or bad day.
Toni Dufficy says
So glad I found your article! My 81 year old dad is in nursing home. He has multiple system atrophy, orthostatic hypotension, congestive heart failure, 1 kidney (other was removed 4 years ago due to cancer), vascular dementia, lost eyesight in left eye due to arterial occlusion, and had significant subdural hematoma on left front quadrant of brain on Feb 1. Needless to say a complicated history. Dad is now in nursing home and has catheter. He can no longer stand or walk due to frequent falls. He started having extreme hallucinations about 6 months ago. They seemed to be under control with seroquel and exelon. Dad has been diagnosed with 3 UTIs in the past 6 weeks. He was seeing people and getting very angry and mean. Complete behavioral change seemed to be signal that he was having UTI. But he doesn’t have any pain. Now doctor has done a culture and thinks he has a colony. Doctor wants to treat with hiprex. Dad is only receiving palliative care except for hallucination medicines. After receiving antibiotics to treat UTIs dad seemed ok. Not this time. For the past 10 days he has been having intense frightening hallucinations. It makes no sense to me to give dad the hiprex given his medical condition. If he has colony my thought even before finding your article is to not treat as you suggest; however, I don’t know how to deal with hallucinations and also let nursing home doctor know I don’t think hiprex is the best treatment option. I am also worried that dad will become more dehydrated (he doesn’t drink much at all now and continually has dark caramel color urine) if he suffers any of the known side effects.
Leslie Kernisan, MD MPH says
Gosh, your poor father! He is going through a lot. Yes, based on what you describe, if he is colonized, it’s not clear to me that he’d be likely to benefit from antibiotic treatment. I suppose it could be tried to see if his hallucinations improve, but I’d be surprised if that solved the hallucinations issue.
If he’s not acutely ill with an infection, then his hallucinations might be due to something affecting his brain; most likely some kind of chronic degeneration, but it could also be made worse by medication side-effects, pain, or other things that trigger vulnerable brains into going haywire.
Honestly, since he is in a nursing home with quite a lot of serious chronic conditions, it might make sense to start by asking a health provider to sit and talk to you about his overall health state and what declines/crises to expect over the next 6-12 months. For many older adults, at a certain point it makes sense to shift the goals of medical care so that they are more focused on comfort and treating symptoms, and less focused on still trying to fight infections and keep people alive as long as possible. Your father’s health providers should be willing to discuss this with you. Good luck and take care!
Su Lee says
My 67 yr old husband has to self cath. He has been getting infusions at an Infections Diesese Clinic for treatment for UTI infections. He had his last treatment two months ago and now the infection is back.
We are concerned his body will become immuned to the medications…then what?
Leslie Kernisan, MD MPH says
Well, this is the problem with frequent antibiotic treatments: the bacteria become resistant and then as health providers, we run out of antibiotic options. Since he has been seen at an infectious diseases clinic, hopefully they have verified that he is having actual clinical UTIs, and not just positive urine cultures. (People who are chronically catheterized are even more likely to have asymptomatic bacteriuria; in general, they should only be treated with antibiotics if they have clinical symptoms, such as fever, pain, etc.)
If he is mostly getting colonized or infected with resistant bacteria…all I can think of would be to otherwise try to bolster his health and immune system, so that he is better positioned to fight off infections. Conventionally trained doctors tend to not particularly focus on this, but some holistically oriented health providers believe they can help patients do this. Good luck!
Joanne dziuba says
If a 93 Alzheimer’s woman is having delirium but doesn’t test positive for UTI but you know it’s not the Alzheimer’s because you live with her, if it cannot be treated by antibiotics, how can it be treated?
Leslie Kernisan, MD MPH says
By “test positive for UTI”, I assume you mean a positive urine culture. If the urine culture is not positive, then it is neither a UTI or asymptomatic bacteriuria. In this case, I would recommend looking for other causes or trigger of delirium or worse than usual confusion. There are many reasons that someone aged 93 with dementia can become delirious, including electolyte imbalances, medication side-effects, other types of infections, other health problems, etc. People can also become more confused than usual due to pain or constipation or other seemingly “minor” issues. Good luck!
Carol Audlee says
I have developed recurrent uti’s this year. I believe I have had 3-4 since a trip to Aruba in January. Culture comes back positive with streptococcus group b bacteria not ecoli. This time greater than 100,000cfu/ml. Usually this type of bacteria. Have been put on different antibiotics in the past. Supposedly allergic to sulfur so last antibiotic was ampecillin. Went away came back now. Have had pelvic CT scan, kidney ultrasound and bladder ultrasound all came back good. Urologist I believe is not going to prescribe antibiotics. Problem is I only have one kidney born that way. Good kidney functions. No symptoms when urinating have noticed maybe a little right side flank pain but could be muscular. I started taking d-mannose and drink lots of fluids. Worried that I may jeopardize my kidney if not treated. Thoughts?? Oh I an 60 and urologist feels it may be related to menopause and may look into a cream. Also microscopic blood in urine. Never had that before. 60 is killing me lol!!!
Leslie Kernisan, MD MPH says
Your situation sounds particularly complicated and sounds like more than garden variety asymptomatic bacteriuria or garden variety UTI. I would recommend continuing to work closely with the urologist. Or you could consider a second opinion from another urologist, perhaps one specialized in women’s health. good luck!
Greg welborn says
My wife has colonized in her bladder/kidneys. She is resistant to all pill antibiotics and would require IV. Plus we are in a nursing home and she has dementia, what are my options for helping her? How do you keep colonized from turning into uti
Leslie Kernisan, MD MPH says
Sorry to hear of your wife’s condition. Unfortunately, it’s not uncommon for nursing home residents with dementia to be colonized. As far as I know, no particular intervention has been proven to keep colonization from becoming a UTI in nursing home residents. Regardless of what is done, your wife will continue to be at some risk of infection because her immune system has weakened due to her age and chronic medical conditions.
I would actually recommend discussing the big picture of her health and what to expect with her doctors. Good luck!
Donna Galluzzi says
Reading your reply was very informative, but I have frequent UTI that are proven with a culture. This has been going on for many years. My urulogis says taking a lot of antibotics is not good.THe only symptom I have is frequent urnition this can be every 1/2 hr to 1 hour. Very stressful. antibiotis help but I worry that it’t not good to always take antibiotics. However going to the bathroom is very taxing. Any suggestions I am almost 84 and in good health. I drink 70 oz of water a day take cystex, I;have heard drinking lemon or vinegar water is good or soda in water if one is coming on. What about sweets or any other foods to harm the bladder and cause recurring problems
Leslie Kernisan, MD MPH says
As I explain in the article, a positive culture does not prove a UTI, because a positive urine culture can also be caused by asymptomatic bacteriuria. When a person is treated repeatedly with antibiotics but the urine culture remains positive, it is often due to asymptomatic bacteriuria.
Frequent urination can be due to bacteria in the urine but can also be caused by other issues. Such urinary frequency is common in older adults. If it is troublesome to you, I would recommend asking your health providers to do further evaluation and treatment for this. This can be done in primary care but honestly is better done in a urogynecology clinic, as they tend to do a more thorough exam and are better versed in different treatment strategies. Good luck!