Population at increased risk

People who have obstructed urinary tract conditions such as kidney-stone or with a history of having incomplete bladder emptying (spinal cord injury, bladder decompensation etc.) are at a higher risk of developing the UTI. Suppression of the immune system (HIV/AIDS patients or patients with diabetes), and use of immunosuppressant medications can also increase the risk of developing a UTI several-fold. Catherization and Hospital-admission increases the risk of all types of infection including UTI [3].

Women: Sexually active women, women who use diaphragm as a birth-control measure are at increased of developing UTI [5].

Men: Though men are less likely to develop UTI, an enlarged prostate can lead to incomplete bladder emptying making them prone to such infections.

Infants: In this group of patients, the bacteria can also gain entry to urinary tract through the bloodstream from other infected sites of the body.

Young Children: Children have difficulty in wiping or cleaning them after the bowel movement. Thus, poor hygiene is linked to increase in the frequency of UTI.

Clinical presentation

Musculoskeletal: There is a constant mild or moderate pain in the pelvic region of women. Among men, similar pain is observed in the rectal region.

Neurological: In patients with UTI most frequently suffer from confusion and drowsiness. In some patients, gait disturbance is also observed.

Urogenital: Some of the urogenital features of the UTI are dysuria, frequent urination, urinary urgency, and abdominal pain. There can be new incontinence or worsening of the pre-existing incontinence in patients with UTI.

• Dysuria: This causes discomfort when contraction occurs during voiding. Dysuria occurs due to acute inflammation
• Increased frequency of urination: The reduced bladder capacity due to edema (because of inflammation) can increase the frequency of urination and pain due to bladder distension.
• Chills, sweats and fever: UTI activates the inflammatory cascade, causing the febrile response.
• Pain in flank: There can be a sudden renal edema causing an increase in pressure and capsular distention causing intense pain in the flank that can radiate to the groin.

Diagnosis of UTI

• While the location of UTI can help to classify the type of infection, it is very difficult to determine the extent of infection just based on the symptoms.
• In elderly, UTI may present only as urinary incontinence, without any other symptoms.
• Urine dipstick test: This test shows the positive nitrate and/or leukocyte esterase indicating the probability of UTI [5].
• A positive urine culture is the true diagnostic test for UTI. The urine culture must be performed in the setting of the clinical infection as asymptomatic bacteriuria is common and does not need any treatment [6].

These tests may be indicated in UTI:

• Urine analysis: This test is performed to check the presence of bacteria by chemical tests such as the presence of nitrites in the urine.
• Complete blood count (CBC) and blood culture are also done in some cases.
• “Clean catch” urine culture can be done to identify the bacteria and its sensitivity to the antibiotics for treatment.
• Imaging: Sometimes CT scan for abdomen, kidney scan and ultrasound, and Intravenous pyelogram (IVP) may also be required to assess the extent of infection.

Treatment of UTI depends on the extent of the infection. 

Mild kidney infections: In mild cases, following an antibiotic regimen for 3 days (women) or 7 - 14 days (men) can benefit the patient. In patients who are pregnant or suffer from diabetes, one must take antibiotics for 7 - 14 days. Drinking plenty of water can help flush the bacteria out of the system.

Severe kidney infections: In severe infections, the patient may have to get admitted to the hospital to receive intravenous fluids and antibiotics for immediate relief. The chances of such visits increase if the patient is elderly; have kidney stones, cancer, diabetes, spinal cord injury or other medical problems.

Recurrent bladder infections: Women must take antibiotics after the sexual contact and clean the pubic region with water. They can also take a single daily dose of an antibiotic to prevent infections.

Chronic UTI: In these cases, UTI persists even after taking antibiotics; such patients must take stronger antibiotics to combat the menace of UTI [7]. Surgery is advised if the infection has affected the anatomy of the excretory system.

Antibiotics that are frequently used to manage UTI are as follows [9]:

• Trimethoprim-sulfamethoxazole
• Fluoroquinolones
• Nitrofurantoin

Most of the infections of the urinary tract can be treated successfully. The symptoms of UTI generally resolve with 24 to 48 hours after the initiation of the treatment. For severe infections, relief can come only after 7 days of treatment.

Though urine is generally sterile, when the infection begins, it starts at the opening of the urethra (the place from where the urine leaves the body) and moves upwards in the urinary tract. In 90% of the cases, the culprit of the uncomplicated infection is a type of bacteria called Escherichia coli, which normally lives in the colon and around the anus [2].

These bacteria can easily move around the anus and urethra. The most common causes of UTI are poor hygiene and sexual intercourse. Emptying of the bladder can help flush out the bacteria from the urethra. However, some bacteria can travel up the urethra to the bladder and grow, causing the infection. When the infection spreads further, these bacteria can even reach the kidney, which is a very serious condition, if not treated promptly.

Other species that cause UTI include Klebsiella, Proteus mirabilis, Enterococcus and Staphylococcus saprophyticus.

Though UTI is more common in adults than in children, the latter is more likely to suffer from its serious form and often get ignored. It is estimated that about 1-2% of the children suffer from UTI.

These infections are more common in women and girls younger than 50 years than their male counterparts, probably due to the anatomic differences between the genders. It is estimated that about 40% women and 12% men have suffered from UTI at least once in their life-time [1].

The following stages can explain the pathogenesis of UTI in humans:

• Colonization: Bacteria colonize in the urethral region of the urinary system. In the absence of proper hygiene, they continue to grow and ascend into the bladder.
• Uroepithelium penetration: Bladder forms the safe haven for the multiplication of the bacteria. After the penetration of the bacteria, they rapidly replicate and may also form a biofilm.
• Ascension: Once there is sufficient colonization and penetration of bacteria, they may ascend the ureters towards the kidney. Fimbria present in this region helps the bacteria to ascend. The bacterial toxins also cause reverse peristalsis in this region, inhibiting the flow of urine.
• Pyelonephritis: When the bacteria reach the renal parenchyma of the kidney, they cause an inflammatory response called pyelonephritis. 
• Acute kidney injury (AKI): If the treatment is not initiated, the bacteria can reach the renal tubules and may cause interstitial nephritis causing AKI.

UTI can be prevented. The following steps can reduce the risk of UTI significantly.

• Drinking plenty of water or liquids ensure frequent urination, preventing the colonization of the bacteria in the bladder.
• Wiping from front to back after urinating bowel movement can prevent the easy passage of the bacteria to the urinary system [10].
• Emptying the bladder immediately after the intercourse and drinking a glass of water help to flush out of bacteria.

Summing up, though UTI is a common disease affecting all the segments of the population, it can be successfully managed and prevented by making people aware of the clinical complications. UTI can also be prevented by incorporating proper hygiene in their daily routine.

Anatomy of the excretory system

Kidneys are small organs that lie on either side of the spine. Apart from removing the waste and excess water from the body, kidneys also play an important role in the regulation of the blood-pressure. These organs are extremely sensitive to the changes in the blood-glucose levels; hence both diabetes and hypertension can adversely affect the working of the kidneys.

There are two ureters that drain the urine from each kidney to the urinary bladder. The bladder stores the urine and when a certain level of urine is collected, it voluntarily contracts to expel the urine.

Urethra connects the bladder to the outside of the body. Infection that involves the kidneys, ureters, urinary bladder and urethra (or excretory system) is called the Urinary Tract Infection (UTI). Any of the parts of this system can be infected and the further up the infection, the greater is the chance of infection to become serious.

Types of infection

• Pyelonephritis: Infection of the upper excretory system namely, kidneys and ureters are called pyelonephritis. It leads to serious symptoms such as fever, chills, nausea and vomiting.
• Urethritis: Infection of the urethra.
• Cystitis: Infection of the bladder.

A urinary tract infection (UTI) is an infection of a part of the urinary tract.

Though there are no specific signs and symptoms of UTI, but when they manifests they may show the following features:

The trouble during urination: There is a persistent and strong urge to urinate. While passing the urine, there is a burning sensation. The urine appears cloudy and sometimes it appears red, pink or cola-colored due to presence of blood.

Frequency of frination: The patient passes small quantity of urine frequently. In fact, the patient may be the distressed with the number of visits to the washroom.

Pain: Pelvic pain and rectal pain is observed in women and men suffering from UTI respectively.

Treatment of UTI depends on the extent of the infection.

1. Foxman B. The epidemiology of urinary tract infection. Nat Rev Urol. Dec 2010;7(12):653-60
2. Dalal S, Nicolle L, Marrs CF, Zhang L, Harding G, Foxman B. Long-term Escherichia coli asymptomatic bacteriuria among women with diabetes mellitus. Clin Infect Dis. Aug 15 2009;49(4):491-7.
3. van der Starre WE, van Nieuwkoop C, Paltansing S, et al. Risk factors for fluoroquinolone-resistant Escherichia coli in adults with community-onset febrile urinary tract infection. J Antimicrob Chemother. Mar 2011;66(3):650-6.
4. Hooton TM, Roberts PL, Cox ME, Stapleton AE. Voided midstream urine culture and acute cystitis in premenopausal women. N Engl J Med. Nov 14 2013;369(20):1883-91.
5. Little P, Turner S, Rumsby K, Warner G, Moore M, Lowes JA, et al. Dipsticks and diagnostic algorithms in urinary tract infection: development and validation, randomised trial, economic analysis, observational cohort and qualitative study. Health Technol Assess. Mar 2009;13(19):iii-iv, ix-xi, 1-73.
6. Lane DR, Takhar SS. Diagnosis and management of urinary tract infection and pyelonephritis. Emerg Med Clin North Am. Aug 2011;29(3):539-52
7. Olson RP, Harrell LJ, Kaye KS. Antibiotic resistance in urinary isolates of Escherichia coli from college women with urinary tract infections. Antimicrob Agents Chemother. Mar 2009;53(3):1285-
8. Wagenlehner FM, Schmiemann G, Hoyme U, Fünfstück R, Hummers-Pradier E, Kaase M, et al. [National S3 guideline on uncomplicated urinary tract infection: recommendations for treatment and management of uncomplicated community-acquired bacterial urinary tract infections in adult patients].Urologe A. Feb 2011;50(2):153-69.
9. Cunha BA. Antibiotic Essentials. 7th ed. Royal Oak, Mich: Physicians Press.; 2008.
10. Jepson RG, Craig JC. Cranberries for preventing urinary tract infections. Cochrane Database Syst Rev. Jan 23 2008;CD001321.