Urinary Tract Infections
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Background
Infections of the urinary tract (UTI’s) are the most common bacterial infections in humans. UTIs are particularly common in women (30% will have a UTI by age 24, 50% will have a UTI in their lifetime). Specifically, bladder infection (termed “acute bacterial cystitis”) is one of the most common reasons for a woman to seek medical attention. UTI’s are most commonly caused by bacteria normally found in the bowel and around the genital skin which ascend through the urethra into the bladder. Infections can ascend even further upstream and infect the kidneys - pyelonephritis.
There are many types of bacterial infection, but most start with an infection of the bladder and progress from there.
Lower Urinary TractInfections usually start in the bladder, but may spread to adjacent, connected organs in males
Cystitis: infection of the bladder (males and females)
Urethritis: infection of the urethra; common site of sexually trasmitted infections such as Chlamydia and Gonorrhea
Prostatitis: infection of the prostate gland
Epididymitis: infection of the epididymis - a small organ behind the testis which stores sperm (males only)
Orchitis: infection of the testis, almost always associated with epididymitis (epididymoorchitis)
Upper Urinary Tract
Pyelonephritis: infection of kidney
Urosepsis: spread of infection from the kidney or other urinary organ to the blood stream and body; can be very severe if the urinary tract is not draining properly (e.g. a stone is present)
"-itis" designates that inflammation is present, however, not all inflammation is a result of microbial infection. Some types of inflammation are 'non-infectious'.
Causes of Urinary Tract Infection
Infection of the urinary tract occurs when microbes gain entry to the urinary tract and overwhelm host defenses resulting in inflammation. Except for the very end of the urethra, the urinary tract is free of bacteria (sterile). Almost all infections are caused by bacteria and almost all bacterial infections are from bacterial ascent - that is, they gain entry from the urinary tract by entering the drainage system from the outside. Infections from microbes other than bacteria are uncommon, but fungus, parasites and viruses can also cause infections.
It also is known that there is a family link. For females with urinary tract infection, if other female relatives in your family have urinary tract infections there can be an increased propensity for infection recurrence (70% vs 40% baseline risk for females).
Women are especially prone to UTIs for a number of reasons. Contrary to popular belief, the infections are not a result of the shorter urethra in women. Nor are the infections a result of hygiene. The increased rate of infections are due to a complex interplay between the defence mechanisms of the body and bacteria which are normally found in the vagina and perianal areas (perineum). The major identifiable risk factors for recurrent infections in women are:
Post-menopausal status (or any circumstance where there is a deficiency of vaginal estrogen)
Cell surface markers (these are genetically transferred) - includes things such as blood group and Lewis antigen status.
Sexual intercourse
Spermicidal lubricants
Alteration in the normal vaginal flora - i.e. colonization with bacteria prone to cause infectiion of the bladder
Elevated post-void residual urine (i.e. urine remaining in the bladder after voiding was completed)
Male UTI’s are far less common and usually require assessment to rule out some anatomic abnormality, such as prostate obstruction (e.g. BPH), urethral stricture, or the like. Your urologist will discuss with you proper assessment with your best interest in mind. Bacterial prostatitis is a particular form of urinary tract infection in men and requires adequate antibiotic therapy to prevent relapse or bacterial resistance – even up to 6 weeks of treatment, or more.
Diagnosis
Your urologist will assess your situation, possibly ordering or performing further tests (e.g. urine testing, kidney (renal) ultrasound, cystoscopy, bladder function testing), and then counsel you in regards to your particular situation as to how you may be able to prevent recurrences. The diagnosis of urinary tract infection is established based on three findings:
* The urine culture results usually take 2-3 days to get back. Therefore, patients are often started on antibiotics because of presumed infection based on symptoms and pus in the urine (which can be tested in the office and results immediately available)
Urinary frequency, urgency, burning combined with pus and blood in the urine are most commonly due to infection. However, it is always important to keep in mind that these findings can be caused by conditions other than infection and that some of them are serious. Therefore, it is important to exclude non-infectious causes for these urinary symptoms in the appropriate circumstances - most especially if the urine culture does not show bacteria. If you are having irritative urinary symptoms that are not responding to antibiotics or the urine cultures do not show bacteria, you must be evaluated for these other causes.
In both men and women, certain conditions may predispose to recurring, more severe or complicated infections and may prompt evaluation or treatment by a urologist. These conditions include diabetes mellitus, previous urinary tract surgery, neurologic diseases affecting bladder function, urinary tract obstruction, and urinary stones. If you suffer from recurring or complicated UTI’s, your family physician may decide to refer you to a urologist for further assessment, to see if some of these underlying problems exist.
Prevention
Often times, urinary tract infection will occur for no good reason other than because of bad luck. We do not fully understand why woman develope urinary tract infections more frequently than men but it is not exclusively (or potentially at all) do to the shorter urethra in woman versus men. Contrary to popular belief, urinary tract infections are rarely do to a tight urethra (urethral stenosis) - though there are exceptions to this. It is much more likely that colonization with the vagina by bacteria which caused urinary tract infection is the major problem. The vagina is usually colonized by friendly bacteria such as lactobacillus which in fact crowd out and kill unfriendly bacteria. Loss of these friendly bacteria may occur following menopauseor following use of broad spectrum antibiotics. The other issue is that some women are inherently susceptible to infection. when bacteria ensured the bladder they are typically flushed out with urination. Some women have "sticky bladders" - bacteria which entered the bladder adhered to the bladder wall which permits then to then invade and cause infection. While we do not fully understand the reasons, there are certain genetic markers on the surface of the bladder (such as blood group markers - A, B, O) which certain types of bacteria have adapted to adhere to.
For patients who are developing recurrent urinary tract infections, it can be helpful to have a sense of purpose in decreasing the frequency of recurrences or trying to eliminate infections altogether. There are some safe, easy conservative things which you can try.
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Emptying the bladder before and after intercourse
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Healthy vaginal flora will displace bad types of bacteria which cause bacterial vaginosis and urinary tract infection. Most supplements contain lactobacillus species - of which there are over 100 types. Loss of the healthy vaginal bacterial flora is common after broad spectrum antibiotic use and after menopause. There are many different types of lactobacillus but the common ones include acidophilus, rhamnosus and casei.
Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 have been shown to reduce the frequency of recurrent infections by about 50%. Pick a supplement that has as many types as you can find from your local pharmacy or health food store.
Most probiotics are taken by mouth, but there may be some advantage to placing the probiotic pill directly in the vagina - those with a gel-cap may need to be cut open and placed in cream (such as KY or vagifem) before placing in the vagina since the gel cap is thick. Others come as a vaginal suppository - for example, Purfem can be placed directly in the vagina as it's thin gel cap will dissolve more easily (note that this is much more expensive than an oral probiotic). Probiotics can be taken as instructed on the bottle, but twice weekly will usually suffice. When placed in the vagina, 3 days in a row is probably effective.
Finding a probiotic with both rhamnosus and reuteri can be difficulty.
Natures Way brand products with "Reuteri" in the label often have both. (not meant as an endorsement of this brand).
Fem Dophilus is another source of L. rhamnosus and retueri.
RepHresh Pro-B contains L. rhamnosus and retueri (available at Pharmasave by special order)
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Extract or non-sweetened juice (cranberry juice has a very low concentration of the active ingredient and is high in sugar, therefore not a good choice). These block bacteria from sticking to the bladder wall. There is evidence to show that it reduced recurrence of urinary tract infections.
The active ingredient is proanthocyanidin. An effective dose of PAC is 36 mg.
Both are reliable sources. This is not meant as an endorsement of either brand.
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This is a type of sugar molecule believed to interfere with adhesion of bacteria to the surface of the bladder.
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Methenamine hippurate or methenamine mandelate. Urinary 'antiseptic'. Converted to formaldehyde in the urine (an acidic urinary environment is necessary) which is a non-specific inhibitor of antibacterial activity.
Dose Methenamine mandelate is 1 gram four times per day
Constipation
There is an association between urinary tract infections and constipation. Treating the constipation will often reduce the risk of urinary tract infections.
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Patients often don't know when they are constipated. The ROME III criteria for constipation is at least 2 of the following:
Straining with at least 25% of defecations.
Lumpy or hard stool with at least 25% of defecations.
Sensation of incomplete evacuation with at least 25% of defecations.
Sensation of obstruction or blockage with at least 25% of defecations.
Manual manoevers to facilitate bowel movements with at least 25% of defecations.
Fewer than 2 defecations per week.
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Managing constipation often is achieved by simple conservative measures that allows patients relief from constipation symptoms.
Conservative measures:
Increasing exercise.
High fiber diet (25-30 grams per day).
Bran Buds. 1/3 cup provides 44% of daily fiber.
Chia seeds are also a good source of fiber. 1 tablespoon has 15% of daily fiber
Ensuring that you are emptying your bowel and bladder regularly through the day.
Adequate water intake.
It is important to note that the function of fiber is to bind and carry water. If fiber is added to an already constipated patient in absence of water, this can make the constipation worse. If you are adding fiber to your diet to treat your constipation it is essential to be drinking at least 1 L of water per day.
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Adding a medication to start the bowels working is often helpful to treating constipation.
The medication with the best evidence is Polyethylene Glycol (PEG). Products that are PEG products are Restorolax or Miralax. These work by softening the stool by increasing the water content of the stool.
The usual dosage of PEG/Restorolax is 17 grams per day. It is often helpful to start at a lower dose and work up to a full adult dose as needed. Some common measurements for PEG are listed below :
1 tablespoon = 15 grams
1 capful = 17 grams
1 packet = 17 grams
1 teaspoon = 4 gram
Other products used for constipation management includes stimulants such as senna that increase the motility of the bowel or mineral oil products. However these are not as strongly recommended.
Treatment
Fortunately, most infections do respond to antibiotics and these are necessary in many cases. Before the advent of antibiotics, most bladder infections would resolve on their own over the course of a few weeks. However, some patients would develop kidney infections which could lead to serious complications such as scarring within the kidney, abscess formation and eventual loss of kidney function. It is important to note, however, that bladder infections in of themselves rarely lead to any sort of long term problems even if they are recurrent and treated appropriated. UTIs other than bladder infection (e.g. kidney and prostate infections) should always be treated.
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The mainstay of treatment for urinary tract infections is antibiotics. Antibiotics either kill or impair the growth of bacteria.
It is important to note that some patients (especially older or those with urinary catheters) may have bacteria in the urine without any symptoms. This is known as asymptomatic bacteriuria and is one instance where treatment is not always necessary (and sometimes should be avoided).
Initial antibiotic treatment is generally based on a ‘best guess’ on what antibiotic will be effective (this is called emperic therapy). Knowing which antibiotic will be effective (and which will not) requires a urine culture which takes 2-3 days.
The duration of antibiotic therapy depends on the type and severity of the infection with more severe infections requiring longer course of antibiotics. Severe infections may require intravenous antibiotics
Duration of treatment for uncomplicated bacterial cystitis is typically 3-5 days. More severe infections may require prolonged durations of treatment, often several weeks. First line antibiotics include the following:
Fosfomycin (Monurol) 3 g single dose.
Macrobid 100 mg twice daily x 5 days.
Septra (Trimethroprim-sulfamethoxazole) SS bid x 3-5 days.
Cepharlosporins (1st generation).
By definition, infections in males are always considered complicated and merit a different approach. A minimum 7 days of treatment with an antibiotic with good tissue penetration (NOT Macrobid or nitrofurantoin) should be used.
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Analgesics such as non-steroidal anti-inflammatories (e.g. ibuprofen) and tylenol.
Bladder antispasmodics (anticholinergic or beta-3 agonists) may help with urinary urgency and frequency.
Pyridium (phenazoperidine) may help with burning.
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Recurrent UTIs are defined as at least 3 UTIs/year or 2 UTIs in the last 6 months.
Management should include evaluation by a urologist. This may include cystoscopy and renal US.
There are several strategies to reduce the risk of recurrent UTIs.
Non-medication prevention: see section above
Medications for prevention.
There are 2 primary strategies using antibiotics.
Prophylactic antibiotics: routine use of antibiotics before infection develops. This is particularly helpful if the infections routinely occur after certain events such as intercourse.
Self-start antibiotics: self-administration of antibiotics after infection develops. Keep a supply of antibiotics with you and start them when symptoms develop. This is useful in motivated patients who have had confirmed infections in the past combined with clear-cut symptoms (they know when the infections are starting). Patients who develop fever, flank pain, any symptoms that suggest infection other than bacterial cystitis (e.g. kidney infection) or who are not responding to antibiotics after a couple of days should seek medical attention immediately.
Vaginal estrogen is very helpful for prevention of recurrent UTIs in women with syndrome of genitourinary menopause (see below).
Vaginal Estrogen & Syndrome of Genitourinary Menopause
Vaginal estrogen is important for the health and wellbeing of the genitourinary tract. Lack of vaginal estrogen may cause Genitourinary Syndrome of Menopause (GSM). This condition is also known as urogenital or vulvar vaginal atrophy. GSM is most commonly seen in post-menopausal women but may also be seen in other conditions such as during treatment for breast cancer.
Genitourinary syndrome of menopause includes:
Vaginal dryness, burning, discomfort or pain
Discomfort with intercourse (dyspareunia).
Increased frequency of urinary tract infections.
Overactive bladder (OAB).
The cause for these symptoms is thinning of the lining of the vagina, reduced mucous secretion, low Lactobacillus bacteria (helpful bacteria), low vaginal pH (acidic). The use of vaginal estrogen has been shown to be highly beneficial in this condition and, on average, can reduce the frequency of recurrent urinary tract infections by 50%. These medications may also be effective for overactive bladder and dyspareunia .
DOI: 10.1016/j.urology.2020.05.034
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There are several formulations available to treat genitourinary atrophy. All are equally effective and are generally low dose.
Estrogen creams:
Premarin 0.625 mg/g; 1 gram 3 times per week. Conjugated estrogen from mares.
Estragyn 0.5 g 3 times per week. Estradiol cream.
Estrogen tablets:
Vagifem 10 mcg daily for 2 weeks, then 2 times/wk
Estrogen rings:
Estring 7.5 mcg/d; replace every 3 months.
Femring 0.05 or 0.1 mg/d; replace every 3 months
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All take 3-6 months to achieve maximal effect.
They are meant to be taken long term.
Creams come with an applicator but sometimes the plastic applicator is uncomfortable. It is often easier to put a toothpaste-like amount on the finger inserted into the vagina.
Estragyn often has less vaginal burning than Premarin and comes in a more convenient size. The cost is equivalent but only Premarin is covered by MSP.
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Vaginal estrogen has not been associated with an increased risk of hormone-dependent cancers and the literature supports the low risk of vaginal estrogen.
Much of this concern comes from the false assumption that vaginal and systemic estrogen treatments have the same risks.
Vaginal estrogen results in high estrogen concentrations in the vagina but not in the blood stream; the reverse is true for systemic estrogen. When vaginal estrogen is used at the doses note above, serum levels of estrogen remain in the normal post-menopausal range (DOI: 10.1097/AOG.0000000000000526).
Several studies have highlighted the safety of vaginal estrogen in patients with breast cancer (DOI: 10.1007/s10549-012-2198-y, DOI: 10.1200/JOP.2011.000352, DOI: 10.1097/AOG.0000000000005294).
WE recommend that patients with a history of breast cancer can discuss their concerns with their oncologist.
On the Web
General Urology Websites
Canadian Urological Association Extensive library of downloadable pamphlets on a wide range of urological conditions
UrologyHealth.org The patient information site of the American Urological Association.