What is a UTI?
A UTI or Urinary Tract Infection is any infection of bladder/urethra (lower urinary tract, “cystitis”, “urethritis”) and kidneys/ureters (upper urinary tract, “pyelonephritis”). The lower urinary tract also includes the prostate, testes, and epididymis in men.
UTIs are almost always the result of bacteria that originate in the colon, colonize the perineum (the area between the anus and vagina or scrotum), and enter the urinary tract through the urethra. Bacteria in the perineum is normal and not related to poor hygiene practices. These bacteria trigger an inflammatory reaction of the urinary tract lining that produces the typical symptoms of infection – burning and pain on passing urine, urgency to urinate, and frequency of urination. The bacteria can be identified on a urine culture that typically takes around 48 hours for results. The urinalysis done at the time of initial assessment cannot 100% confirm a UTI but is often sufficient to initiate treatment while we wait for the final culture results.
How Common are UTIs?
Approximately 60% of women will experience a bladder infection in their lifetime and 20-40% of women will have an additional UTI. Of these, 25-50% will experience multiple recurrent UTIs. The evaluation and treatment of UTIs costs several billion dollars globally each year. It is estimated that 15% of all community prescribed antibiotics are for UTIs.
Why am I Being Referred to a Urologist?
Urologists are surgical specialists who diagnose and treat diseases of the urinary system which includes the bladder, kidneys, ureters, and urethra in men and women, as well as the male reproductive system and prostate.
The majority of women who experience UTIs have normal urinary tracts. In other words, there is no underlying urological disease such as urinary tract cancer, kidney stones, or a urinary drainage problem. Because of this, urological investigations often fail to identify a source for infections but, in some cases, testing such as imaging and cystoscopy are indicated to be certain. In men, UTIs are uncommon and most men with UTIs require urological investigations.
The following information is intended to help you understand UTIs and does not replace consultation with your health care provider.
What Factors Increase My Chance of a UTI?
There are many myths surrounding UTI risk factors. The following is a list of factors for which there is good quality evidence to support their role in UTIs.
Fluid Intake
There is good evidence to support that drinking at least 1.5 L (50 oz or 6 cups) of fluid reduces UTI risk. With hydration, then proportion of women having > 3 UTIs per year declined from 88% to < 10%.
Estrogen
Low estrogen levels most commonly occur because of natural menopause. It is important to recognize that estrogen levels can be relatively low in the 5-10 years prior to complete cessation of menstruation. Low estrogen states can occur in the setting of cancer treatment (for example, hormonal treatments for breast cancer, chemotherapy, pelvic radiation), hormonal contraception, and lactation (breast-feeding). Low estrogen states result in an increase in vaginal pH and a change in vaginal flora with a decrease of the “good bacteria” lactobacillus. Low estrogen makes it difficult for the urethral and bladder lining to function normally to defend against bacteria.
Sexual Function
The mechanism by which intercourse increases the chance of infection in women is not well understood. However, the frequency of sex correlates to the rate of UTI. Spermicidal use increases the rate of infection by 2 x. A new sex partner also doubles the UTI rate.
Lower Urinary Tract Dysfunction (LUTD)
LUTD refers to abnormal function of the bladder and bladder outlet (urethra, urinary sphincter, and prostate). There are many forms of LUTD which include problems with bladder emptying, urinary incontinence (leakage), and bladder prolapse. These conditions can often be diagnosed simply by reviewing symptoms and performing a physical exam in the office, and basic lab tests.
Medical Conditions
There are supporting indirect data to support controlling blood glucose in patients with diabetes and optimizing other general medical conditions reduces the risk of UTIs.
Genetics
There is a relationship between the frequency of infection and family history of UTIs in one’s mother – this can increase the rate of infection by at least 2x. It is suspected that there may be a genetic predisposition that increases the ability of bacteria to stick to the urinary tract lining.
Disruption of the Vaginal and Intestinal Microbiota
There are indirect data to support that UTI risk is increase by disruption of normal vaginal microbiota by harsh cleansers, and prolonged antibiotic courses (> 5 days), broad spectrum, and unnecessary antibiotics. Related, is a theory that alteration in the food intake and travel may affect UTI risk by way of influencing the gut microbiota which, as mentioned above, is the source of pathogenic bacteria.
**Myths** Surrounding UTI Risk Factors
There are many factors that have been proposed as risk factors for UTIs but the evidence is simply not good enough to strongly advise the following However, if it makes sense for you there is no harm in modifying the following:
Wiping habits: front-to-back vs. back-to-front
Voiding before or after sexual intercourse
Vaginal douching
Tampons
Wearing tight clothing
Type of clothing
Bicycle riding
Obesity
Swimming
Bubble baths
Hot tub use
How Can I Reduce the Chance of UTIs?
Although it may not be possible to avoid UTIs 100% of the time, the following is a list of factors shown to reduce the chance of UTIs. It is important to note some UTIs recur after antibiotics if the type or duration of antibiotic was not optimal, or if there was a significant delay in initiating treatment. These are issues to review with your health care provider.
**Best Evidence**
Hydration
There is good evidence to support that drinking at least 1.5 L (50 oz or 6 cups) of fluid reduces UTI risk. Water is best, but anything ingested that promotes urine production should produce the same effect (see Healthy Bladder Habits & Bladder Retraining)
Low Dose Vaginal Estrogen
Vaginal estrogen reduces UTI risk by (1) reducing vaginal pH, reducing bacterial colonization, restoring lactobacillus and (2) improving vaginal lubrication, thereby reducing trauma to the vagina and urethra during intercourse, etc. This is a prescription product, typically a cream or suppository inserted into the vagina twice per week (see Estrogen & Lower Urinary Tract Function ).
Sexual Function
Limiting the frequency of sex and avoiding spermicides can reduce UTI risk. It has been shown that having sex 4-8 times per month increases the rate of UTI by 6 x, while having sex 9 times per month increased the rate of infection by 10 x.
Cranberry Supplements
There is evidence that cranberry supplements with 36 mg proanthocyanidins A (a substance in cranberries that makes it difficult for bacteria to stick to the urinary tract lining) helps reduce UTI risk (see Additional Resources for Bladder Function).
**Weak Evidence**
D-mannose
This is a type of sugar that demonstrates inhibition of bacteria’s adhesion to uroepithelial cells in the lab and although commonly recommended by health professionals, data to support its use is poor, including the recent study from JAMA 2024.
Probiotics
These are microorganisms that are involved in balancing the “bad” and “good” bacteria that cause infections in the body. The probiotic strain lactobacillus may help prevent UTIs by making it difficult for bacteria to stick to the bladder lining. Vaginal suppository forms Lactobacillus crispatus, rhamnosus GR- 1 and reuteri RC-14 may restore vaginal lactobacilli and decrease recurrent UTI compared with placebo, but quality data is lacking.
Vitamin C (ascorbic acid)
Vitamin C may increase the acidity of urine, helping to kill bacteria. Result of studies are not sufficient to recommend. In addition, excessive use can increase the risk of urinary tract stones.
Low Dose Antibiotic Prophylaxis
Although one of the goals of UTI prevention is to avoid antibiotic side effects including bacterial resistance, on occasion judicious use of low dose antibiotics for a limited time can reduce the overall antibiotics use and suffering from UTI symptoms. This can provide a “buffer” while one is optimizing some of the other lifelong non-antibiotic strategies for UTI prevention. Options most commonly include continuous antibiotic prophylaxis (often x 3-12 months) and post-coital (after sex) antibiotic prophylaxis. Other individualized variations on antibiotic prophylaxis are possible.
UTI Vaccines
The 1st North American studies have been reported in 2024 and the outcomes are promising!
Online Resources
SUFU UTI Tutorial: An Interactive Tutorial to Help with Frequent Urinary Tract Infections
https://sufuorg.com/resources/patients/uti.aspx
Urology Care Podcast: Getting Real About Urinary Tract Infections with Dr. Yahir Santiago-Lastra
Selected References
Recurrent Uncomplicated Urinary Tract Infections in Women: AUA/CUA/SUFU Guideline. J Urol. 2019 Aug;202(2):282-289. Anger J, Lee U, Ackerman AL, et al. https://www.auanet.org/guidelines-and-quality/guidelines/recurrent-uti
Updates to Recurrent Uncomplicated Urinary Tract Infections in Women: AUA/CUA/SUFU Guideline. The Journal of Urology. 2022, 208 (4), 754-756. Bixler, B. & Anger, J.
Effect of Increased Daily Water Intake in Premenopausal Women With Recurrent Urinary Tract Infections A Randomized Clinical Trial. JAMA Intern Med. 2018;178(11):1509-1515. Thomas M. Hooton, MD, Mariacristina Vecchio, PharmD, Alison Iroz, PhD et al.
Risk Factors for Recurrent Urinary Tract Infection in Young Women. The Journal of Infectious Diseases. 2000; 182:1177–82. Delia Scholes,1,2 Thomas M. Hooton, 3 Pacita L. et al.
d-Mannose for Prevention of Recurrent Urinary Tract Infection Among Women: A Randomized Clinical Trial. JAMA Intern Med. Published online April 08, 2024. Hayward G, Mort S, Hay AD, et al.
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