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]
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 150million 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 35years.[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]
^ abcColgan R, Williams M, Johnson JR (September 2011). "Diagnosis and treatment of acute pyelonephritis in women". American Family Physician. 84 (5): 519–526. PMID21888302.
^ abcNicolle LE (February 2008). "Uncomplicated urinary tract infection in adults including uncomplicated pyelonephritis". The Urologic Clinics of North America. 35 (1): 1–12, v. doi:10.1016/j.ucl.2007.09.004. PMID18061019.
^Cite error: The named reference statspe was invoked but never defined (see the help page).
^ abcdefghSalvatore S, Salvatore S, Cattoni E, Siesto G, Serati M, Sorice P, Torella M (June 2011). "Urinary tract infections in women". European Journal of Obstetrics, Gynecology, and Reproductive Biology. 156 (2): 131–136. doi:10.1016/j.ejogrb.2011.01.028. PMID21349630.
^ abLane DR, Takhar SS (August 2011). "Diagnosis and management of urinary tract infection and pyelonephritis". Emergency Medicine Clinics of North America. 29 (3): 539–552. doi:10.1016/j.emc.2011.04.001. PMID21782073.
^Ferroni M, Taylor AK (November 2015). "Asymptomatic Bacteriuria in Noncatheterized Adults". The Urologic Clinics of North America. 42 (4): 537–545. doi:10.1016/j.ucl.2015.07.003. PMID26475950.
^Glaser AP, Schaeffer AJ (November 2015). "Urinary Tract Infection and Bacteriuria in Pregnancy". The Urologic Clinics of North America. 42 (4): 547–560. doi:10.1016/j.ucl.2015.05.004. PMID26475951.
^"Recurrent uncomplicated cystitis in women: allowing patients to self-initiate antibiotic therapy". Prescrire International. 23 (146): 47–49. February 2014. PMID24669389.
^Colgan R, Williams M (October 2011). "Diagnosis and treatment of acute uncomplicated cystitis". American Family Physician. 84 (7): 771–776. PMID22010614.