A urinary tract infection, commonly known as a UTI or bladder infection, is a condition all of you should be able to treat with confidence. Essentially it’s just a bacterial infection that can either affect the lower urinary or upper urinary tract.
Anatomy of the urinary system
The urinary tract consists of the urethra (the tube that carries urine from the urinary bladder to the outside), urinary bladder (which stores urine) -note the use of – urinary- to differentiate between the gall bladder, two ureters (the tubes that carry urine from the kidneys to the bladder) and two kidneys (filter blood to produce urine).
To make it easy to study the various structures within the urinary system, scientists group these structures into those that belong to the upper division and those that belong to the lower division.
The upper urinary tract in women consists of the ureters and kidneys, while the lower urinary tract consists of the urethra and bladder- on a side note, males also have something called a prostate, which is also part of the lower urinary tract.
Lower urinary tract infections and upper urinary tract infections
A lower urinary tract infection (also known as cystitis and, as previously mentioned, bladder infection) affects the lower urinary structures, i.e. the infection stays in the bladder.And an upper urinary tract infection (also known as pyelonephritis) affects the upper urinary structures.
Urinary tract infection terminology
You have already learned about classifying UTIs based on the structures affected, i.e., upper UTI or lower UTI, but there is another classification based on the likelihood of the disease-causing complications: complicated UTIs and uncomplicated UTIs.
Unfortunately, there are no set criteria that would class an individual as either having a complicated UTI or an uncomplicated UTI; as such, for the purpose of this article, an uncomplicated UTI is:- an otherwise healthy non-pregnant female patient with symptoms of a lower UTI.
Conversely, a patient will be classed as having a complicated UTI if they have fallen within any of the following; (1) are pregnant; (2) male gender; (3) immunosuppressed (e.g., advanced HIV or neutropenia); (4) suffer from renal disease; (5) individuals with risk factors that predispose them to be persistent or relapsing infection (e.g., calculi, indwelling catheter or other drainage devices).
How to diagnose a UTI?
The diagnosis of a UTI is not that difficult as long as you understand the following; (1) the cause (also termed aetiology); (2) the alterations in the body’s normal function (i.e. pathophysiology); (3) the signs, symptoms (also known as the clinical manifestation) and risk factors of a UTI; (4) how to differentiate between other conditions that may mimic a UTI – also called a differential diagnosis- ; (5) how patients commonly present; (6) how to manage a UTI and (7) when to refer.
UTI pathophysiology in women
The opening of the anal canal is close to that of the urethra. Therefore, any bacteria lurking around the anal canal can migrate to the urethra and irritate the cells. But it doesn’t stop here. In actual fact, the bacteria can then make their way up to the urinary bladder causing symptoms of a lower UTI or affecting the kidneys via the ureters causing symptoms of an upper UTI.
UTI aetiology
Aetiology of a urinary tract infection includes the following; (1) Escherichia coli (E-coli) is the most frequent microbial cause of lower UTIs (around 75 to 95 % of cases), with occasional infections caused by Klebsiella pneumoniae and Staphylococcus saprophyticus– don’t worry about these two for now just remember E-coli. And (2) E-coli commonly resides in the gut and can readily colonize the area around the urethra due to the close relationship between the opening of the anal canal and the urethra, something I have explained earlier.
UTI risk factors
Risk factors
Knowing the risk factors that predispose someone to a UTI can be extremely valuable. For example, if you have a patient with symptoms of a UTI and the patient has the risk factors (which we will discuss below), then the patient’s probability of having a UTI is more likely.
The risk factors for a UTI in pre-menopausal and post-menopausal women differ and are presented below.
Risk factors for a UTI in pre-menopausal women of any age include; (1) Diabetes – because high levels of glucose in the urine create a favourable environment for bacteria- ; (2) diaphragm use – this can kill protective bacteria in the vagina and alter pH ; (3) history of UTIs and or UTIs in childhood ; (4) sexual intercourse and; (5) past medical history of kidney stones- this can lead to blockage or changes in the flow of urine.
Risk factors for post-menopausal women and other older women include; (1) Estrogen deficiency – estrogen has a protective function- ; (2) functional or mental impairment ; (3) History of UTIs before menopause ; (4) urinary catheterization – bacteria can enter the bladder easier; (5) urinary incontinence – can lead to a build-up of bacteria.
Symptoms of urinary tract infection in a woman
Signs and symptoms of urinary tract infection in females
Symptoms of urinary tract infection for females with a lower UTI consist of dysuria (fancy term for pain on urination), urinary frequency, urinary urgency, and suprapubic pain (lower abdominal pain).
It is also common for patients to present with hematuria (blood within the urine) because the infection can damage the lining of the urinary tract causing red blood cells to leak into the urine. You may detect hematuria on urinalysis – termed microscopic hematuria (= blood in urine not visible with the naked eye)- or observed visibly within the sample- termed macroscopic or gross hematuria.
Major causes of hematuria
Below are common causes of hematuria
- UTIs
- Kidney disease
- Kidney stones
- Kidney infection
- Trauma
- Kidney, bladder or prostate cancer
- Enlarged prostate ( also known as benign prostatic hyperplasia)
- Endometriosis ( a condition in which tissue similar to the inside of the uterine wall grows outside the uterus)
- Diseases of the ureter(s) such as malignancy, stones, stricture (narrowing)
- Mimics of hematuria (e.g. Mensuration, drugs, foods)
- Vigorous exercise
It is important to remember the following; (1) the red colour change in urine does not necessarily reflect the degree of blood loss- so if you see blood in urine, do not panic and assume the patient will bleed to death.; (2) hematuria present with signs and symptoms of UTI is fairly common and transient, i.e. short-lasting. However, if you have a patient who presents with hematuria that is not explained by an obvious condition (e.g. UTI) or persists beyond the UTI – then you should refer the patient for further investigation.
The above highlights the importance of following up with patients with hematuria – or any ailment for that matter- to confirm it has resolved or ensure appropriate referral where necessary.
Symptoms of urinary tract infection in elderly woman
Symptoms of cystitis can be difficult to detect, and patients may not actively give this information to you- – this is why your communication and consultation skills (also referred to as history-taking skills).
Patients (usually those of 65 years and above; but this is not a strict definition) present with symptoms that are not classic for a UTI, such as;
(1) chronic dysuria; (2) urinary incontinence; (3) general sense of feeling unwell; (4) issues with gait (fancy term for observing someone’s walk) or falls; (5) change in mental status (e.g., confusion- the mechanism is still not fully understood) – so be careful!
Symptoms of urinary tract infection in pregnant woman
Pregnant women are more susceptible to UTIs for a number of reasons. The first is that the pregnancy itself causes changes in the urinary tract. The expanding uterus puts pressure on the bladder, which can lead to urine pooling and an increased risk of infection. In addition, pregnancy hormones can make it easier for bacteria to attach to the urinary tract.
The most common symptom of a UTI in a pregnant woman is a burning sensation when urinating. Other symptoms may include:
- cloudy or bloody urine
- strong-smelling urine
- pelvic pain
- back pain
- fever or chills
- fatigue
A UTI can cause serious health complications for both you and your baby if it is not treated promptly.
The differential diagnosis for urinary tract infections
UTI mimics
Below is a list of conditions that cause symptoms similar to a UTI, and I would like you to focus on those features that are only present in these conditions but not a UTI – think of the activity spot the difference!
1. Vaginitis (=inflammation of the vagina) – Think of this if you have a patient with dysuria but also has any of the following; (1) vaginal discharge or odour – not common in UTI ; (2) vaginal pruritus (=itch) ; (3) dyspareunia (=painful sexual intercourse) ; (4) absence of urinary frequency.
Causes of vaginitis include;
a) Yeast infections– key features differentiating from UTI include vaginal burning, soreness, and irritation. In addition, patients may have little to no discharge. The discharge is classically described as white and thick with no or minimal odour.
b) Trichomoniasis – common signs and symptoms of acute infection include a malodorous (=smelly) thin discharge associated with burning and itch. Patients may also report the following features, which are also common in UTIs; dysuria, frequency, lower abdominal pain, or dyspareunia.
c) Bacterial vaginosis – key features include (1) vaginal discharge and/or (2) odour. The discharge is usually off-white with an unpleasant ”fishy smell” – non of these features are present in a UTI, but 50-75% of women with bacterial vaginosis are asymptomatic.
2. Urethritis (=inflammation of the urethra)- You should consider this in female patients who are sexually active and have dysuria, so sexually active females should prompt you to investigate further. Furthermore, urethritis is likely increased if you detect pus in urine (i.e., pyuria) but no bacteria (i.e., bacteriuria). Causes include; chlamydia, gonorrhoea, trichomoniasis, herpes simplex, and noninfectious irritants such as contraceptive gels.
3. Painful bladder syndrome- This should be considered if you have a patient who presents with ongoing bladder discomfort with symptoms of dysuria, frequency, and/or urgency but no evidence of infection or other cause.
4. Pelvic inflammatory disease– This is easy. The presence of fever with lower abdominal or pelvic pain with or without dysuria should raise suspicion.
How to diagnose a patient with a suspected UTI?
You should suspect a lower UTI in patients who present with dysuria, urinary frequency or urgency, and/or suprapubic pain in the absence of vaginal symptoms. Moreover, the probability of a lower UTI is greater than 50% in women with any of the above symptoms, and if patients report dysuria combined with frequency without vaginal discharge, the likelihood is greater than 90%.
To diagnose a lower UTI, you don’t usually need to undertake a physical examination- although the physical examination is typically normal, you may find some patients have abdominal tenderness.
However, I would encourage you to always document patient vital signs (which include measuring; (1) pulse, (2) oxygen saturation levels, (3) respiratory rate, and (4) blood pressure), all of which should be normal. However, urinalysis is a valuable diagnostic tool in women with clinical features that are not clearly suggestive of a lower UTI.
Moreover, if on urinalysis there was the absence of pyuria (=presence of white blood cells in urine) – typically always present in women with lower UTI – then it strongly suggests an alternative diagnosis, i.e. something else may be causing the symptoms.
What is a urinalysis?
Urinalysis is a procedure for examining urine. The Siemens GP Multistix dipstick is commonly used for urinalysis within a clinical setting.
In conjunction with the patient’s health history and physical examination, urinalysis can identify urinary tract infections and diseases. In actual fact, as a pharmacist, this is a tool that is readily accessible to us all, and you should know how to interpret the findings.
Components of a urinalysis consist of; (1) Gross assessment of the urine- here, you will directly observe the colour, odour, and consistency of the urine; (2) urine dipstick analysis- here, you dip a specially treated paper into a sample of urine and can look for the presence of blood within the urine, protein, glucose, ketones, leukocyte esterase and nitrites ; (3) urine microscopic analysis – this involves looking at the sample under a microscope.
The role of urinalysis and uncomplicated UTI diagnosis
Findings on a dipstick suggestive of UTI include either of the following ; (1) leukocyte esterase (reflecting white blood cells in the urine, i.e., pyuria) or (2) nitrites (reflecting gram-negative organisms in urine, i.e., bacteremia).
Other findings which may be present but not specific to UTI include; (1) hematuria- more common in the setting of UTI but not in urethritis or vaginitis. This can be helpful when differentiating between likely causes of symptoms; (2) cloudy urine (white or yellow) may be evidence of infection; (3) foul urine odour- suggestive of bacteria in the urine.
The management of a patient with an uncomplicated UTI
The management of lower UTIs includes prompt treatment with antimicrobial therapy (also known as antibiotic treatment). However, before starting antibiotic treatment, it is crucial to take into account; (1) risk factors for drug resistance, (2) local and national guidelines, and (3) patient suitability for treatment.
Uncomplicated UTI treatment options
First-line antibiotic treatment options include; (1) Nitrofurantoin 100mg modified release capsules – this is usually considered before other first-line agents (usual dosage 100mg twice a day for three days); (2) Trimethoprim 200mg tablets – this can be considered if there is low resistance (usual dosage 200mg twice a day for three days).
Consider Pivmecillinam (400mg initial dose, then 200mg three times a day for a total of 3 days) or Fosfomycin (3g single-dose sachet) if; (1) there has been no improvement in symptoms with the use of first-choice antibiotics or (2) first choice antibiotics not suitable.
Remember to always consult local guidelines and the updated version of the British National Formulary BNF as resistance to antibiotic treatments can vary from area to area, which is not reflected in national guidelines.
Antimicrobial resistance public health
Possible reasons for inadequate treatment regimens include; (1) the use of sub-optimal doses, (2) the wrong choice of antibiotic, and (3) duration of therapy.
Poor patient compliance is another significant factor that can lead to treatment failure. This may be due to patients forgetting to take their medication or not taking it as prescribed. For example, skipping doses or stopping treatment early.
It is important to be aware of the possible reasons for antimicrobial resistance as this can help us to avoid selecting resistant strains. When prescribing antibiotics, it is essential to choose the most appropriate drug at the correct dose for the recommended duration of therapy. To ensure this, it is necessary to have a good understanding of the different types of possible reasons for the re-emergence of antimicrobial resistance, including; (1) the overuse and misuse of antibiotics, (2) inadequate treatment regimens, and (3) poor patient compliance.
The overuse and misuse of antibiotics is the most important factor contributing to the development of resistance. Antibiotics are commonly used unnecessarily, for example, to treat viral infections such as colds and flu. Inappropriate use can also select resistant strains. For example, using broad-spectrum antibiotics when a narrower spectrum antibiotic would suffice. Sub-optimal dosing is another form of inappropriate use. This can occur when patients do not complete the full course of therapy or when they self-medicate with leftover antibiotics.
The inadequate duration of therapy is another factor that can lead to the development of resistance. For example, patients may stop taking their antibiotics too soon because they feel better or are worried about the side effects. It is essential to finish the full course of therapy, even if you are feeling better, to ensure that all the bacteria are killed and to reduce the chances of the infection coming back.
Lastly, poor patient compliance is a significant problem that can lead to treatment failure. Patients may forget to take their medication or not take it as prescribed. For example, skipping doses or stopping treatment early. It is essential to follow the instructions given by your healthcare provider to ensure that the antibiotics have time to work and to prevent resistance from developing.
UTIs are one of the most common infections that can develop as a result of this resistance, and so it is important that we know how to treat them effectively. With the right treatment and care, it can help to reduce the spread of resistance and keep patients healthy.
What are recurrent urinary tract infections?
A recurrent urinary tract infection (UTI) is an infection that comes back after you have been treated for a previous UTI.
The causes of recurrent urinary tract infections are usually due to the bacteria that cause the initial infection not being completely eradicated from the body. This can happen if you do not finish the full course of antibiotics prescribed or if the bacteria are resistant to the antibiotics used.
Symptoms of recurrent urinary tract infections can vary depending on the individual but may include frequent urination, burning sensation when urinating, cloudy or bloody urine, and pelvic pain.
Treatment of recurrent urinary tract infections usually involves re-treatment with the same antibiotics that were used to treat the initial infection. However, if the bacteria are resistant to the first line of antibiotics, your healthcare provider may prescribe a different antibiotic.
Prevention of recurrent urinary tract infections can be achieved by taking measures to reduce your risk of developing an infection in the first place. This includes drinking plenty of fluids, urinating regularly, and wiping from front to back after using the toilet. You may also be prescribed a prophylactic antibiotic to take after you have been treated for a UTI.
Antibiotic prophylaxis and urinary tract infections
Urinary tract infections (UTIs) are a common problem, especially in women. They can be painful and uncomfortable and, if left untreated, can lead to serious kidney damage.
There are several things that can reduce the risk of developing a UTI, such as drinking plenty of fluids, urinating regularly, and wiping from front to back after using the toilet. You may also be prescribed a prophylactic antibiotic to take after you have been treated for a UTI.
Prophylactic antibiotics are a form of prevention that involves taking a course of antibiotics when there is no current infection, and the person is at risk of developing one. The best candidates for this form of prevention are people with chronic kidney disease, paralyzed or bedridden patients, those who have had a catheter inserted, and those who are living in long-term care facilities.
The use of antibiotics prophylaxis can reduce the incidence of UTIs. However, there is a risk of developing resistance to the antibiotics if they are used too often or for too short a duration. It is important to finish the full course of therapy, even if you are feeling better, to ensure that all the bacteria are killed and to reduce the chances of the infection coming back.
For those with recurrent UTIs, different antibiotics may be required. Prevention of recurrent urinary tract infections can be achieved by taking measures to reduce the risk of developing an infection in the first place. This includes drinking plenty of fluids, urinating regularly, and wiping from front to back after using the toilet. A prophylactic antibiotic to take after being treated for a UTI may also be required.
Antibiotic prophylaxis is an effective method to reduce the risk of urinary tract infections in susceptible populations. However, it is important to finish the full course of therapy to prevent resistance from developing. With the right treatment and care, it can help to reduce the spread of resistance and keep patients healthy.
Patient information for those suffering from a UTI
Self-care measures such as using simple analgesia and drinking at least 2 litres of water to avoid dehydration are recommended. However, there is no evidence for recommending cranberry products or urine alkalinizing agents.
In addition, it is encouraged to make the following lifestyle changes; (1) wiping from ‘front to back’ – prevents colonization of bacteria around the urethra; (2) avoid soaps, shower gels, and ‘intimate hygiene products- this may remove the natural protection of the vaginal secretions; (3) limit washing of vaginal area to once a day- ‘over washing’ may remove healthy vaginal secretions.
Lastly, constipation can also lead to urinary tract infections. A possible explanation is a large amount of stool can cause the bladder to not empty well- increasing the risk of bacterial growth. As such, you should also advise patients on how to treat constipation if present.
Alarm features and when to refer patients for further care
Refer patients with the following features ; (1) unable to maintain hydration; (2) suspected urinary obstruction (symptoms can include lower abdominal pain, changes in urination- patients do not always report less urination, trouble starting to urinate, feeling of a full bladder); (3) alerted vital signs; (4) suspected pyelonephritis (also referred to as a kidney infection).
Symptoms of pyelonephritis you should be familiar with include; (1) fever and/or chills – be careful if patients have recently taken painkillers as they can affect vital signs; (2) flank pain or costovertebral angle tenderness (located on your back at the bottom of the rib cage at the 12th rib)- note I did not mention lower back pain because it is not always suggestive of a kidney infection; (3) nausea and vomiting; (4) altered mental state- be careful with the elderly reporting episodes of confusion.
When to request a urinary sample
This is not usually required. However, as a pharmacist, you should be aware of circumstances that would require you to send a urine sample for further investigation.
Consider sending a urine sample for; (1) patients with upper UTI and for men, children, and pregnant women with symptoms suggesting a lower UTI. And (2) patients with increased risk factors for resistance (i.e., urinary abnormalities, impaired renal function, immunosuppressed, previous resistant UTI, care home resident, recent hospitalization or treatment failure); (3) patients > 65 years – dipstick testing is not recommended in this group, due to the frequency of bacteriuria which may be incidental.
