What is UTI?
Urinary tract infection is UTI, so first you should know about urinary tract. Urinary tract consist of two kidneys, two ureters, one bladder and one urethra. Kidney plays a very important role in excretion of metabolic waste products and formation of urine. The ureters drain urine from kidney and deliver it to the bladder. Function of bladder is to store urine and then release during micturition. The urethra is the tube through which urine passes from the bladder to the exterior of the body. The female urethra is around 2 inches long and ends inferior to the clitoris and superior to the vaginal opening. In males, the urethra is around 8 to 10 inches long and ends at the tip of the penis.
Infection in the urinary tract caused by microorganisms and most common bacteria is E.coli derived from gastrointestinal tract. UTI is the term commonly used to describe urethritis and cystitis, infection in the urethra called as urethritis and infection in the bladder is called as cystitis. But infection can be in any part of the urinary tract from the kidney to urethra. Microorganisms or bacteria can travel from urethra to bladder, bladder to ureter, and ureter to the kidney which may result in pyelonephritis (infection in the kidney).
Urinary tract is divided in to
Upper urinary tract consist of kidney and ureter and
Lower urinary tract consist of bladder and urethra.

Causes of UTI
E.coli is the most common microorganism to infect urethra but other microbes proteus, pseudomonas, streptococci, staphylococci and klebsiella are also common. Chlamydia and Mycoplasma can infect the urethra and reproductive system but not the bladder. Chlamydia and Mycoplasma infections may be sexually transmitted and require treatment of sexual partners.
UTI is more common in women because in women, the ascent of organisms into the bladder is easier than in men; the urethra is shorter and the absence of bactericidal prostatic secretions may be relevant.
Sexual intercourse may cause minor urethral trauma and transfer bacteria from the perineum into the bladder.
Risk Factors of UTI
1. Poor Hygiene
2. Using dirty toilets
3. Multiple sexual partner or new sexual partner
4. Using a diaphragm for birth control, because it may slow urinary flow and allow bacteria to multiply.
5. Condom use may also cause UTI because of minor vaginal trauma during intercourse.
6. Tampons and spermicidal jelly may cause irritation of vaginal and surrounding skin which can result in UTI.
7. Pregnancy
8. Menopause (atrophic urethritis and atrophic vaginitis)
9. Nerve damage around bladder or in spinal cord injury patient can not completely empty bladder which can allow bacteria to grow.
10. Using catheters in bedridden patients.
11. Diabetes
12. Bowel incontinence
13. Any instrumentation in the bladder or urethra during surgery.
14. Kidney stones
15. Enlarged prostate
16. Inappropriate use of antibiotics (interrupt natural flora of gastrointestinal tract and urinary tract).

Symptoms of UTI
Symptoms of UTI depends upon age, gender, other associated disorders, presence of catheter and the site of infection.
1. Abrupt onset of frequency of micturition and urgency.
2. Dysuria (pain in the urethra or burning sensation during micturition).
3. Pain in lower abdomen during and after urination.
4. Cloudy urine with an unpleasant odor.
5. Sometimes blood in urine (hematuria which may be microscopic or visible).
6. Fever (when infection reached to kidney, usually in catheterized patients but it can be the first symptom in men).
7. Nausea and vomiting if infection is severe.
Acute Pyelonephritis is a condition when infection spreads to the kidney, recognized by fever with chills, rigors, nausea, vomiting, loin or back pain, hypotension, guarding or rigidity may be an indication of hospitalization.
Diagnosis-
1. Clinical symptoms with medical and surgical history.
2. Investigations/lab tests-

      Urine Dipsticks
Urine microscopy and cytometry
Urine Culture to know microorganism

For these tests patient is asked to collect clean catch urine by washing and wiping genital area and midstream urine sample in a sterile container, so that bacteria around the genital area cannot come in to the urine sample and will prevent the confusion of test results.
       Blood test for complete blood count, urea and electrolytes in infants, children and patients with fever or any complicated infection.
       Blood culture
Imaging tests-
USG (ultrasonography)– Ultrasound uses a device, called a transducer, that bounces safe, painless sound waves off organs to create an image of their structure.
CT scan – CT scans use a combination of x rays and computer technology to create three-dimensional (3-D) images.
MRI – MRI machines use radio waves and magnets to produce detailed pictures of the body’s internal organs and soft tissues without using x rays.
Radionuclide scan– A radionuclide scan is an imaging technique that relies on the detection of small amounts of radiation after injection of radioactive chemicals. Special cameras and computers are used to create images of the radioactive chemicals as they pass through the kidneys.
Urodynamics – Urodynamic testing is any procedure that looks at how well the bladder, sphincters, and urethra are storing and releasing urine. Most of these tests are performed in the office of an urologist—a doctor who specializes in urinary problems—by a urologist, physician assistant, or nurse practitioner. Some procedures may require light sedation to keep a person calm.
Cystoscopy – looking inside the bladder and urethra with a camera lens inserted via the urethra through a long thin tube.
Pelvic examination in women and rectal examination in men.
Investigations to diagnose UTI depends upon age, gender clinical symptoms and severity of infection thus use selectively.
Treatment of UTI
Because UTI caused by microorganisms mostly bacteria so antibiotics are recommended to treat the UTI, after getting the results of urine culture which usually takes 48-72 hours. For lower UTI usually 3 days course of antibiotics are recommended. Trimethoprim is the first choice of treatment if bacteria is trimethoprim sensitive, but for trimethoprim resistant bacteria nitrofurantoin or quinolones are effective.
In severe infections treatment may continue for 7-14 days, depending upon patient’s condition doctor decides for intravenous or oral treatment.
Penicillins and cephalosporins are safe to use in pregnancy but trimethoprim, sulphonamides, quinolones and tetracyclines should be avoided.
Fluid intake of 2-3 liters and urinating frequently is usually recommended to flush out the toxins of kidney.
Prevention of UTI
1. Good personal hygiene
2. Drink plenty of fluids around 3 liters per day
3. Urinate frequently if you feel to empty the bladder, do not hold for long time
4. Cranberry juice helps to prevent infection.
5. Urinate before and after sexual intercourse.
6. Wipe from front to back after toilet, in that way bacteria will not come from anal region to urethral region.
7. During menstruation change pads frequently and tampons use should be avoided.
8. Use non-spermicidal lubricated condoms, because spermicidal jelly is skin irritant which cause bacteria to grow and results in UTI.
9. Use cotton and loose fitting underwear and clothes to keep area around urethra dry.
10. Avoid irritant feminine products like deodorant sprays, powders or douches which irritate urethra.
11. Quit smoking
12. Choose healthy diet rich in fibers, protein.
13. Avoid caffeine, nicotine, carbonated soft drinks, spicy food and alcohol.

Please note: Any medical information published on this website is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care professional.

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Content source– Davidson’s Principles and Practice of Medicine (22nd edition), The National Institute of Diabetes and Digestive and Kidney Diseases niddk.nih.gov