Introduction
Susceptibility to illnesses depends on many factors some of which may be environmental, genetic or socio-economic factors. This paper examines urinary tract infection (UTI), its pathogenesis, and how it affects different segments of populations. Diagnosis as well as treatment and management options for UTIs will also be discussed.
Definition and explanation of urinary tract infection
Urinary tract infection (UTI) is defined as “the detection of more than 105 organisms per mL of suitably collected urine” (Brightwater Care Group, 2011, p. 2). Various terms associated with UTI include recurrent UTI, which refers to repetitive episodes of UTI (three or more times a year). Relapse refers to a repeat of UTI with the same strain of organism. Asymptomatic bacteriuria refers to the presence of bacteria without any symptoms. Epidemiologically, UTIs can be categorized into different groups such as: catheter associated versus non-catheter associated UTIs, or UTIs acquired in hospitals (nosocomial) versus UTIs acquired in the community. UTIs can also be accompanied by symptoms (asymptomatic UTIs) or not (non-symptomatic UTIs). UTI affects both men and women but it is more common among sexually active women. Majority of UTI cases are uncomplicated and therefore empirical treatment is normally provided to the patients without the need for a pre-therapy urine culture (Bahadin, Teo & Mathew, 2011).
Pathogenesis of Urinary Tract Infections
Escherichia coli (E. coli) is the most common microorganism that causes UTIs (Rubin & Strayer, 2011). The microorganism is a bacterium and resides in the gastrointestinal tract. When the bacterium gains access to the urinary tract, it causes an infection (Porth & Matfin, 2009; Lee & Bishop, 2002). “Women are more vulnerable to UTIs than men because they have a shorter urethra and the distance between the urethra and the anus is short” (Rubin & Strayer, 2011). The likelihood of developing an UTI can also be increased by mechanical obstruction of the urinary tract, for instance, by an enlarged prostate or insertion of urinary catheters into the urethra (Braun & Anderson, 2006; American College of Physicians, 2007).
In healthy women, majority of the uropathogens come from the rectal flora and enter the bladder through the urethra. One of causes of UTIs in women is the vaginal acquisition of uropathogens from their sexual partners. UTIs accompanied by symptoms develop when the release of cytokine is stimulated by uropathogens in the bladder or the kidney. Besides the longer distance between the urethra and the anus, men generally have low prevalence of UTIs because the environment surrounding their urethra is also drier as compared to the urethra of the women (Braun & Anderson, 2006).
UTIs in women and men
In adult women, UTI is the most common cause of all bacterial infections, especially in young sexually active women. Approximately fifty percent of all women experience at least one episode of UTI in their lifetime. Sexual activity is a risk factor for developing UTIs for women in the 20-40 age brackets (Schaeffer, 2002). On the other hand, a decline in the levels of estrogen is a risk factor for the menopausal women, that is, women aged 55 and above (Akram, Shahid & Khan, 2007; Butler, Hillier & Roberts, 2006). On the other hand, UTIs are not a common occurrence among men, particularly young men. Young men with symptoms resembling those of UTI are in most cases suffering from sexually transmitted infections (STI) rather than UTIs. However, age is a risk factor for developing UTIs among both women and men (see table 1) and is common among men aged 50 and above due to a larger prostate gland (Foxman, 2002).
Table 1: Prevalence of asymptomatic bacteriuria in men and women
Besides sex and age, other risk factors for developing UTIs include presence of indwelling catheters, pregnancy, diabetes mellitus, urologic abnormalities, spinal cord injuries, and prior history of UTI (Bahadin et al., 2011).
Clinical manifestation of UTIs
Urinary tract infections sometimes may not cause any symptoms. These types of UTIs are referred to as asymptomatic UITS. Other times, the symptoms presented may be mistaken for any other sexually transmitted diseases. Nevertheless, for symptomatic UTIs, patients may present various signs and symptoms, which may indicate either the development of a lower or upper urinary tract infection (Braun & Anderson, 2006).
Symptoms of UTIs include: dysuria, frequency of passing urine, urgency to pass urine, urinary incontinence, and suprapubic discomfort. Sometimes haematuria may be present in females. All these symptoms indicate that UTI is present in the patient. The clinicians should also check for the patient’s vital signs. Fever may indicate that the patient has upper urinary tract infection (UUTI). Other symptoms of UUTI include: pain in the back, flank pain, suprapubic discomfort on abdominal palpation and burning on micturition (Braun & Anderson, 2006).
Diagnosis of Urinary Tract Infections
Diagnosis of UTIs depends largely on the symptoms presented by patients when they visit a physician. The most basic diagnosis involves taking the patient’s history and undertaking a physical examination (Mori, Lakhanpaul & Watson, 2007). However, uncertainty surrounds the accuracy with which UTI clinical assessments are done. In women, for instance, the presence of vaginal discharge and vaginal itch may indicate other problems such as STIs, and may necessitate alternative diagnoses and pelvic examinations.
Diagnosis may also involve completion of a urinary frequency volume chart to determine the patient’s problems in passing urine. Assessing the patients’ measurement of flow rate as well as post void residual volume is also useful in diagnosing UTIs (American College of Physicians, 2007).
UTIs can also be diagnosed using urine samples and urine microscopy. Symptomatic bacteriuria can be predicted if the turbidity of the urine sample has a specificity of 66.4% and sensitivity of 90.4%. Urine microscopy can also be undertaken but in this approach, the sensitivity and specificity have wide variations of 60-100% and 49-100%, respectively (Scottish Intercollegiate Guidelines Network, 2006). Concerns about the health and safety at work, maintenance of equipment and skills of health professionals surround urine microscopy and it is therefore rarely used especially in primary or secondary care settings. Whichever the diagnostic method chosen, the accuracy of the assessment is critical in ensuring that the appropriate treatment is given so as to avoid prolonging symptoms and development of complications.
Besides urine samples and urine microscopy, dipstick tests can also be used to diagnose UTIs. However, this test should only be used in patients presenting minimal signs and symptoms of UTIs and whose probability of having UTI is low. Whereas positive dipstick tests may indicate a high probability of bacteriuria, negative tests do not always mean that the patient lacks the infection, hence the need for further tests such as the urine culture (Scottish Intercollegiate Guidelines Network, 2006).
Management and Treatment of Urinary Tract Infections
The treatment of UTIs has four main objectives: to relieve the symptoms, to get rid of the infection, to prevent recurrence, and to prevent complications that may arise from the infection (Mori et al., 2007). Clinical course and treatment options available for patients with uncomplicated and complicated lower UTIs include: trimethoprim, cephalexin, amoxicillin with clavulanic acid, and norfloxacin.
Trimethoprim
This drug is used to treat lower UTI in men and women who are not pregnant. The drug however may lead to renal impairment or may increase the concentration of serum creatinine hence the need to reduce the dosage if these happen. Women should be given 300 mg orally for 5 days or for 10-14 days if the UTI relapses. Men on the other hand should be given 300 mg orally for 2 weeks. The common side effects from taking trimethoprim include fever, itchiness, rashes, nausea and vomiting (National Institute for Health and Clinical Excellence, 2010).
Cephalexin
This drug can be given as an alternative to trimethoprim if the patient acquires infections while taking trimethoprim. The dosage for women is 500mg orally for 5 days while men should be given the same amount for 14 days. The dosage should be reduced if there are signs of severe renal impairment. The main adverse effect from this drug is cholestatic hepatitis although it is very rare (Bullock & Manias, 2010).
Amoxicillin with clavulanic acid
This treatment is given to patients when the organism becomes resistant to trimethoprim and cephalexin. The dosage depends on the amoxicillin content. The adverse effects from the treatment include a temporary increase in liver enzymes and bilirubin as well as the possibility of interaction with warfarin. The dose should be reduced if there are symptoms of moderate or severe renal impairment. Persons aged 55 and above have a high risk of developing hepatitis from taking this treatment (National Institute for Health and Clinical Excellence, 2010).
Norfloxacin
This drug is used to treat patients with complicated UTIs resulting from susceptible organisms such as E Coli, Pseudomonas and Klebsiella, which are resistant to other antibiotic drugs. Patients should take 400 mg for 7-10 days and the drug should be taken on an empty stomach; either one hour before or two hours after meals. The most common adverse effects arising from the drug include headaches, depression, dizziness, convulsions, insomnia and hypersensitivity (National Institute for Health and Clinical Excellence, 2010).
Health promotion and prevention of UTIs
The use of the drugs mentioned earlier helps in relieving the symptoms of UTIs. However, UITs and their possible recurrences can be prevented through health-promotion measures. Drinking plenty of water is important in keeping the urinary tract healthy and free from bacteria. Individuals should also take plenty of vitamin C or its supplements because vitamin C has been found to increase the acidity of the urine thereby creating an impossible environment for bacterial colonization. Cranberry juice is also good in preventing the development of UTIs (Scottish Intercollegiate Guidelines Network, 2006). Relieving oneself of urine as frequently as possible is useful in preventing the development of UTIs because retaining urine in the bladder for prolonged periods of time creates a breeding ground for bacteria. For women, it is important to avoid using feminine hygiene products because they irritate the urethra.
Conclusion
Urinary tract infections are caused by bacteria that enter the urinary tract. The infection affects both men and women but it is more common among women. Various risk factors increase the likelihood of developing UTIs and include: aging, use of urinary catheters, being sexually active, diabetes mellitus, injuries of the spinal cord and pregnancy. UTIs can be diagnosed through physical examination and/or urinalysis. Treatment options given to UTI patients depend on their sex and resistance to other antibiotic drugs. However, effective management of UTIs and prevention of recurrence depend largely on accurate assessment of the infection.
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