Urinary Tract Infection
The vast majority of urinary tract infections are related to bacteria that live in the bowel, with Eschericia coli (E. coli) being the most commonly identified organism. Other microbes may be found and attributed to sexual activity, such as chlamydia and mycoplasma. Fungi and viruses may also be identified.
Urinary tract infections (UTIs) are the second most common type of infection in the body. Everyone has some risk of contracting a UTI, however women are more susceptible due to the shorter length of the urethra and close proximity of the urethral meatus to the vagina and anus. Any malformation of the renal system (i.e. hydronephrosis, kidney stone, enlarged prostate) increases the risk of acquiring UTIs. Those with spinal cord injuries or other nerve damage that prevents complete emptying of the bladder are also at greater risk. Pregnancy puts women at additional risk, most probably due to hormonal changes and shifting in the positioning of the urinary tract. Diabetes is an additional risk factor, as increased sugar in urine is an excellent growth medium for bacteria. The presence of drainage tubes or catheters can act like a ladder for microorganisms to gain access into the urinary tract. Catheters are a known contributor to nosocomial infections. The need for urinary catheters in the hospital setting should be evaluated daily, and they should be discontinued as soon as possible to prevent hospital acquired infections requiring additional hospital days.
The urinary tract is equipped with several natural defenses that help ward off infection. The attachment point of ureters to the kidneys acts like a one way valve, preventing urine from refluxing back up into the kidney. Any damage or anomaly at this point increases the risk of infection. In men, the prostate gland produces natural secretions that slow bacterial growth. Men have less frequent UTIs; however, they are more prone to reoccurrence, as bacteria can hide deep inside prostate tissue. In both sexes, the process of urination flushes out bacteria, and natural immune systems help to suppress infection. It follows that any patient with a depressed immune system (ie chemotherapy) will be at increased risk. Despite our body’s natural defenses, it is inevitable that > 50% of women will experience a UTI in their lifetime.
Most UTIs are not serious and respond well to antibiotics. If not properly treated, infection can recur and become chronic. Ascending to the kidney can cause permanent damage including scarring, decreased renal function, high blood pressure. Some acute kidney infections that develop suddenly can progress to sepsis which can be life threatening.
Diagnosis
Signs and symptoms of UTIs include the following:
- Pain or burning with urination
- Fever, tiredness, or shakiness
- Frequent urination
- Pressure in lower abdomen
- Foul odor, cloudy, or reddish appearance to urine
- Back pain and pain below the ribs
A UTI is diagnosed by both patient’s reported history of symptoms and urine lab testing. The patient will be often asked to give a “clean catch mid-stream” urine sample. This prevents bacteria around the genital area from contaminating the sample. Bacteria can be found in the urine of healthy individuals, but the presence of leukocytes or blood on a simple urine dipstick, together with patient history will confirm diagnosis of UTI. For patients with recurring infection or hospitalized patients, a culture and sensitivity should be performed on the sample to assure the correct antibiotic is given.
If a patient has recurrent UTIs the health care provider may order further testing. Ultrasound of the kidney and bladder is useful. It is non-invasive and poses no risk to the patient, but may not reveal all important abnormalities.
A voiding cystourethrogram may be helpful in identifying the cause of recurrent infection. It is more invasive than an ultrasound and does not require anesthesia. A radiopaque contrast is inserted into the full bladder via a small catheter, and then X-rays are taken while voiding from different angles. This test can reveal an abnormal flow of urine, such as reflux of urine from the ureter back into the renal pelvis. It can also determine if the bladder is being fully emptied.
A cystoscopy may be performed as well. This will provide visual confirmation of redness, swelling, and tissue changes of the urethra and bladder. Urodynamics are tests that focus on the bladder’s ability to hold urine, and then empty steadily and completely. Nerve damage can be detected as well. Both are minimally invasive but may be uncomfortable to the patient and may require light sedation.
References:
https://www.niddk.nih.gov/health-information/urologic-diseases/urinary%2…
https://medlineplus.gov/urinarytractinfections.html
Recent Comments