Urinary tract infection (UTI)

 

Urinary tract infection (UTI)

What is the urinary tract?

The urinary tract makes and stores pee. It includes:

·        Kidney

·        Ureters

·        Bladder

·        Urethra

1.     The kidneys are two bean-shaped organs that filter your blood. Kidneys are small, bean-shaped organs on the back of your body, above your hips. Most people have two kidneys. They filter water and waste products from your blood, which becomes pee. Common wastes include urea and creatinine.

Your kidneys filter about 200 quarts of fluid every day — enough to fill a large bathtub. During this process, your kidneys remove waste, which leaves your body as urine (pee). Most people pee about two quarts daily. Your body re-uses the other 198 quarts of fluid.

Your kidneys also help balance your body’s fluids (mostly water) and electrolytes. Electrolytes are essential minerals that include sodium and potassium.

2.     What is a uterus?

Your uterus is a pear-shaped organ in the reproductive system   of people assigned female at birth (AFAB). It’s where a fertilized egg implants during pregnancy and where your baby develops until birth. It’s also responsible for your menstrual cycle.  

What does a uterus do?

Your uterus plays a key role in your reproductive health and function. The three main jobs of your uterus are:

• Pregnancy: Your uterus stretches to grow your baby during pregnancy. It can also contract to help push your baby out of your vagina.
• Fertility: Your uterus is where a fertilized egg implants during conception and where your baby grows.
• Menstrual cycle: Your uterine lining is where blood and tissue come from during menstruation.

3.     Urethra

The urethra is the tube that lets urine leave your bladder and your body. If you were assigned male at birth, your urethra passes through your prostate and into your penis. If you were assigned female at birth, your urethra is much shorter. It runs from your bladder to open in front of your vagina.

What does the urethra do?

The urethra is part of your urinary system. This system is made up of your kidneys, bladder, ureters and urethra. Your kidneys clean your blood and produce urine, a waste product. From your two kidneys, two ureters move the urine to the bladder, where it’s stored until you urinate (pee). Urine leaves your body through a hole at the end of your urethra. That hole from the inside to the outside is called the urethral meatus. (The term ‘meatus’ refers to any opening from the inside to the outside.

A urinary tract infection (UTI) is an infection in any part of the urinary system. The urinary system includes the kidneys, ureters, bladder and urethra. Most infections involve the lower urinary tract — the bladder and the urethra.

Women are at greater risk of developing a UTI than are men. If an infection is limited to the bladder, it can be painful and annoying. But serious health problems can result if a UTI spreads to the kidneys.

Health care providers often treat urinary tract infections with antibiotics. You can also take steps to lower the chance of getting a UTI in the first place.

Urinary tract infections (UTIs) are one of the most frequent clinical bacterial infections in women, accounting for nearly 25% of all infections. Around 50–60% of women will develop UTIs in their lifetimes. Escherichia coli is the organism that causes UTIs in most patients. Recurrent UTIs (RUTI) are mainly caused by reinfection by the same pathogen. Having frequent sexual intercourse is one of the greatest risk factors for RUTIs. In a subgroup of individuals with coexisting morbid conditions, complicated RUTIs can lead to upper tract infections or urosepsis. Although the initial treatment is antimicrobial therapy, use of different prophylactic regimens and alternative strategies are available to reduce exposure to antibiotics.

Classification of UTI

UTIs are classified into six categories.

 The first category is an uncomplicated infection; this is when the urinary tract is normal, both structurally and physiologically, and there is no associated disorder that impairs the host defense mechanisms.

The second category is a complicated infection; this is when infection occurs within an abnormal urinary tract, such as when there is ureteric obstruction, renal calculi, or vesicoureteric reflux.

The third category, an isolated infection, is when it is the first episode of UTI, or the episodes are 6 months apart. Isolated infections affect 25–40% of young females.

The fourth category, an unresolved infection, is when therapy fails because of bacterial resistance or due to infection by two different bacteria with equally limited susceptibilities.

The fifth category, reinfection, occurs where there has been no growth after a treated infection, but then the same organism regrows two weeks after therapy, or when a different microorganism grows during any period of time.

The sixth category, relapse, is when the same microorganism causes a UTI within two weeks of therapy; however, it is usually difficult to distinguish a reinfection from a relapse.

Clinical Diagnosis

Common symptoms of a UTI are dysuria, urinary frequency, urgency, suprapubic pain and possible haematuria. Systemic symptoms are usually slight or absent. The urine may have an unpleasant odour and appear cloudy

Diagnosis of RUTI depends on the characteristic of clinical features, past history, three positive urinary cultures within the previous 12-month period in symptomatic patients and the presence of neutrophils in the urine (pyuria).

The probability of finding a positive culture in the presence of the above symptoms and the absence of vaginal discharge is around 81%.

In a complicated UTI, such as pyelonephritis, the symptoms of a lower UTI will persist for more than a week with systemic symptoms of persistent fever, chills, nausea and vomiting.

The presence of irritative voiding symptoms between perceived episodes of UTI suggests a non-infectious cause as seen in interstitial cystitis, urethral syndrome or detrusor muscle over activity.

General therapy and consultancy

Patients should be advised and encouraged to drink plenty of fluids (two to three litters per day) and to urinate frequently to help flush bacteria from the bladder. Holding urine for a long time allows bacteria to multiply within the urinary tract, resulting in cystitis. Preventive measures related to sexual intercourse may reduce the recurrence rate. Moreover, women are encouraged to clean the genital areas before and after sex and to wipe from front to back, which will reduce the spread of E. coli from the perigenital area to the urethra.

Avoiding multiple sexual partners will reduce the risk of both UTIs and sexually transmitted infections. Women are encouraged to avoid spermicidal contraceptives, diaphragms and vaginal douching, which may irritate the vagina and urethra and facilitate the entry and colonization of bacteria within the urinary tract. Skin allergens introduced to the genital area, such as bubble bath liquids, bath oils, vaginal creams and lotions, deodorant sprays or soaps are better avoided as they could alter vaginal flora and ultimately result in UTIs.

Antimicrobial therapy

Antimicrobial therapy is the core treatment for UTIs, with the main objective being the eradication of bacteria growth in the urinary tract through an efficacious, safe and cost-effective antimicrobial agent. This can be achieved within hours if the antibiotics are maintained at sufficient urine levels. In order to ensure compliance and be patient-friendly, the drug should be given for a short period of time to prevent bacterial resistance. Antimicrobial agents should be prescribed according to the susceptibility of the infecting bacteria, the concentrations of uropathogens in the urine and the urinary complaint. This is important to consider when there is septicaemia or parenchymal infection, as antimicrobials are usually at higher levels in the urine than in serum.

Dose modification is required for patients with renal insufficiency and in the case of other factors such as: age, pregnancy or lactation status, primary or recurrent infections, hospitalized patients, DM, liver disease, an immune compromised state, hydration levels and psychiatric problems.

Ampicillin, amoxicillin, and sulfonamides are no longer the drugs of choice for empirical treatment because of the widespread emergence of resistance in 15–20% of E. coli in several areas of the USA and other countries. Nitrofurantoin or amoxicillin/clavulanic acid remain effective in terms of bacterial sensitivity, but nitrofurantoin needs to be avoided in patients with pyelonephritis because of its poor serum and tissue levels. Less than 5% of E. coli strains are resistant to nitrofurantoin, whereas other strains are often resistant to it. Penicillin’s and cephalosporin’s are considered safe during pregnancy, but trimethoprim, sulphonamides, and fluoroquinolones should be avoided. Oral antibiotic therapy resolves 94% of uncomplicated UTIs, although recurrence is not uncommon. In the recently published International Clinical Practice Guidelines for the Treatment of Acute Cystitis, a 3-day regimen of trimethoprim-sulfamethoxazole (TMP-SMX) and a 5-day course of nitrofurantoin are recommended as a first-line therapy for the management of uncomplicated UTIs. A 5-day course of nitrofurantoin has an efficacy equivalent to a 3-day TMP-SMX course.

3- to 7-days regimen of beta-lactams, such as cefaclor or amoxicillin/clavulanic acid, is appropriate when first-line therapies cannot be used. Although a 3-day course of fluoroquinolones can be quite effective, it is not usually recommended as first-line therapy because of the emerging resistance to them and their potential side effects, as well as the high cost; nevertheless, fluoroquinolones are the drug of choice in women who are experiencing low tolerance or an allergic reaction after empirical therapy.

In a meta-analysis, a single-dose regimen of fosfomycin trometamol has been shown to be a safe and effective alternative for the treatment of UTIs in both pregnant and non-pregnant women, as well as in elderly and paediatric patients, but it seems to be slightly less effective than the above mentioned therapies. Pivmecillinam in a 3- to 7-day course is also effective, but not available in most regions. Because of its poor efficacy, amoxicillin and ampicillin should not be used for the empirical treatment of UTIs.

 

 

ACUTE SELF-TREATMENT

The patient self-treatment management strategy is an ideal effort to decrease overall antibiotic consumption, and for women who are not suitable candidates for long-term daily prophylaxis. Schaeffer showed that “self-start therapy” should be confined to those women who are self-motivated and have good compliance. A patient needs to consult a physician immediately if she becomes pregnant or if there is any change in symptoms, an increased recurrence of episodes of infection, or no change in symptoms within 48 hours of antimicrobial treatment. These patients can effectively self-treat RUTIs by initiating a standard 3 day course of recommended antimicrobials with minimum side effects.