Urinary tract infection
Infection that affects part of the urinary tract / From Wikipedia, the free encyclopedia
A urinary tract infection (UTI) is an infection that affects a part of the urinary tract.[1] Lower urinary tract infections may involve the bladder (cystitis) or urethra (urethritis) while upper urinary tract infections affect the kidney (pyelonephritis).[10] Symptoms from a lower urinary tract infection include suprapubic pain, painful urination (dysuria), frequency and urgency of urination despite having an empty bladder.[1] Symptoms of a kidney infection, on the other hand, are more systemic and include fever or flank pain usually in addition to the symptoms of a lower UTI.[10] Rarely, the urine may appear bloody.[7] Symptoms may be vague or non-specific at the extremities of age (i.e. in patients who are very young or old).[1][11]
Urinary tract infection | |
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Other names | Acute cystitis, simple cystitis, bladder infection, symptomatic bacteriuria |
Multiple white cells seen in the urine of a person with a urinary tract infection using microscopy | |
Specialty | Infectious disease, Urology |
Symptoms | Pain with urination, frequent urination, feeling the need to urinate despite having an empty bladder[1] |
Causes | Most often Escherichia coli[2] |
Risk factors | Catheterisation (foley catheter), female anatomy, sexual intercourse, diabetes, obesity, family history[2] |
Diagnostic method | Based on symptoms, urine culture[3][4] |
Differential diagnosis | Vulvovaginitis, urethritis, pelvic inflammatory disease, interstitial cystitis,[5] kidney stone disease[6] |
Treatment | Antibiotics (nitrofurantoin or trimethoprim/sulfamethoxazole)[7] |
Frequency | 152 million (2015)[8] |
Deaths | 196,500 (2015)[9] |
The most common cause of infection is Escherichia coli, though other bacteria or fungi may sometimes be the cause.[2] Risk factors include female anatomy, sexual intercourse, diabetes, obesity, catheterisation, and family history.[2] Although sexual intercourse is a risk factor, UTIs are not classified as sexually transmitted infections (STIs).[12] Pyelonephritis usually occurs due to an ascending bladder infection but may also result from a blood-borne bacterial infection.[13] Diagnosis in young healthy women can be based on symptoms alone.[4] In those with vague symptoms, diagnosis can be difficult because bacteria may be present without there being an infection.[14] In complicated cases or if treatment fails, a urine culture may be useful.[3]
In uncomplicated cases, UTIs are treated with a short course of antibiotics such as nitrofurantoin or trimethoprim/sulfamethoxazole.[7] Resistance to many of the antibiotics used to treat this condition is increasing.[1] In complicated cases, a longer course or intravenous antibiotics may be needed.[7] If symptoms do not improve in two or three days, further diagnostic testing may be needed.[3] Phenazopyridine may help with symptoms.[1] In those who have bacteria or white blood cells in their urine but have no symptoms, antibiotics are generally not needed,[15] unless they are pregnant.[16] In those with frequent infections, a short course of antibiotics may be taken as soon as symptoms begin or long-term antibiotics may be used as a preventive measure.[17]
About 150 million people develop a urinary tract infection in a given year.[2] They are more common in women than men, but similar between anatomies while carrying indwelling catheters.[7][18] In women, they are the most common form of bacterial infection.[19] Up to 10% of women have a urinary tract infection in a given year, and half of women have at least one infection at some point in their lifetime.[4][7] They occur most frequently between the ages of 16 and 35 years.[7] Recurrences are common.[7] Urinary tract infections have been described since ancient times with the first documented description in the Ebers Papyrus dated to c. 1550 BC.[20]