A urinary tract infection is an infection that involves any part of the [[urinary tract]]. It can result due to the invasion by a bacteria, virus, fungus or any other pathogen. The most common cause of a [[urinary tract infection]] is a bacterial [[infection]]. Various factors are associated with the risk of developing a urinary tract infection. A common cause of the [[urinary tract infection]] in hospital settings is the urinary catheter placement.
Depending on the site of the infection a [[UTI]] can be classified as either upper or lower [[UTI]]. [[UTI|Lower UTI]] includes [[urethritis]], [[prostatitis]], [[asymptomatic bacteriuria]] and [[cystitis]] (bladder infection) where as [[UTI|Upper UTI]] may include Pyelonephritis (infection of the kidney) and rarely uretritis (infection of the ureters). Each subtype of [[urinary tract infection]] can also be sub classified on the basis of [[duration]], [[etiology]] or therapeutic approach as [[acute]], [[chronic]] or [[recurrent]] and as [[uncomplicated]] or [[complicated]] infections.
The urine is normally sterile, a urinary tract infection occurs when the normally sterile [[urinary tract]] is infected by [[bacteria]], which leads to irritation and [[inflammation]]. Females are more prone to the development of [[UTI]]s because of their relatively shorter [[urethra]]. [[Pyelonephritis]] and [[Cystitis]] result mostly from ascending infections from the urethra ([[Urethritis]]) but can also result from descending infections i.e hematogenous spread, or by the [[lymphatic system]]. The condition more often affects women, but can affect either gender and all age groups. Bacteria does not have to travel as far to enter the [[bladder]], which is in part due to the relatively short distance between the opening of the [[urethra]] and the [[anus]]. The pathogenesis of a complicated [[UTI]] may include obstruction and stasis of urine flow.<ref name="pmid10969044">{{cite journal| author=Hooton TM| title=Pathogenesis of urinary tract infections: an update. | journal=J Antimicrob Chemother | year= 2000 | volume= 46 Suppl A | issue= | pages= 1-7 | pmid=10969044 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10969044 }} </ref> ''[[escherichia coli]] ("E. coli")'', a bacterium found in the lower gastrointestinal tract is one of the most common culprits. [[Diabetes]], [[Crohn's disease]], iatrogenic causes, [[endometriosis]], [[pelvic inflammatory disease]], [[urinary obstruction]], and [[bladder incontinence]] are some other risk factors for acquiring a [[UTI]]. An important aspect in the management of [[UTI]]s is that the individual infection must be differentiated from various causes of [[dysuria]] such as [[cystitis]], [[acute pyelonephritis]], [[urethritis]], [[prostatitis]], [[vulvovaginitis]], [[urethral stricture]]s or diverticula, [[benign prostatic hyperplasia]] and [[neoplasm]]s such as [[renal cell carcinoma]] and cancers of the bladder, prostate, and penis.<ref name="pmid11989635">{{cite journal| author=Bremnor JD, Sadovsky R| title=Evaluation of dysuria in adults. | journal=Am Fam Physician | year= 2002 | volume= 65 | issue= 8 | pages= 1589-96 | pmid=11989635 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=11989635 }} </ref><ref name="pmid9606306">{{cite journal| author=Kurowski K| title=The woman with dysuria. | journal=Am Fam Physician | year= 1998 | volume= 57 | issue= 9 | pages= 2155-64, 2169-70 | pmid=9606306 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=9606306 }} </ref>
A recent challenge in combating [[UTI]]s is the fact that the pathogens are developing resistance to various antibiotics very fast.<ref name="pmid15206056">{{cite journal| author=Hooton TM, Besser R, Foxman B, Fritsche TR, Nicolle LE| title=Acute uncomplicated cystitis in an era of increasing antibiotic resistance: a proposed approach to empirical therapy. | journal=Clin Infect Dis | year= 2004 | volume= 39 | issue= 1 | pages= 75-80 | pmid=15206056 | doi=10.1086/422145 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15206056 }} </ref> A large proportion of patients with acute uncomplicated urinary infections will recover without treatment within a few days or weeks. If left untreated, some patients may progress to develop recurrent infection, [[cystitis]], [[pyelonephritis]], [[hematuria]], and rarely [[renal failure]]. [[Prognosis]] is generally good for lower [[UTI]]s. The majority of patients with cystitis do not have recurrence or complications after treatment.<ref name=nid>Urinary Tract Infections in Adults. NIDDK 2016. http://www.niddk.nih.gov/health-information/health-topics/urologic-disease/urinary-tract-infections-in-adults/Pages/facts.aspx. Accessed on February 9, 2016</ref> A detailed and thorough medical history from the patient is necessary. Specific areas of focus when obtaining a history from the patient include use of urinary catheters, [[pregnancy]], sexual history, [[diabetes]], recent antibiotic use, history of renal disease, [[urinary incontinence]], and [[urinary retention]]. Symptoms of cystitis include abnormal urine color (cloudy), blood in the urine, [[frequent urination]] or [[urgent need to urinate]], painful urination, pressure in the lower pelvis or back, [[flank pain]], [[back pain]], [[nausea]], [[vomiting]], and [[chills]].<ref name=hhh> Cystitis-acute. MedlinePlus.https://www.nlm.nih.gov/medlineplus/ency/article/000526.htm Accessed on February 9, 2016</ref> Patients with an uncomplicated [[UTI]] are usually well-appearing. A thorough physical exam is very helpful in differentiating Upper from Lower [[UTI]]]s and to diagnose exactly within these categories too. Common physical examination findings of cystitis include [[fever]] and suprapubic tenderness where as pyelonephritis also has flank tenderness and chills.<ref name="pmid22010614">{{cite journal| author=Colgan R, Williams M| title=Diagnosis and treatment of acute uncomplicated cystitis. | journal=Am Fam Physician | year= 2011 | volume= 84 | issue= 7 | pages= 771-6 | pmid=22010614 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22010614 }} </ref> Laboratory tests used in the diagnosis of a [[UTI]] include [[urinalysis]] and [[urine culture]]. Laboratory findings consistent with the diagnosis of a [[UTI]] include pyuria and either [[white blood cell]]s (WBCs) or [[red blood cells]] (RBCs) on urinalysis and a positive urine culture. Leukocyte esterase test and nitrite test are very important in this regard. Antimicrobial therapy is indicated in case of a symptomatic [[UTI]]. The treatment of a [[UTI]] depends on the type of the disease, the disease course (acute uncomplicated vs. complicated), history of the individual and the rates of [[Drug resistance|resistance]] in the community. Preventative measures to avoid a [[UTI]] include abstinence from sexual activity, use of barrier contraception during sexual intercourse, urinating after intercourse, increasing fluid intake and frequency of urination, and use of [[estrogen]] (among [[Postmenopausal|post-menopausal]] women). Single-dose [[prophylactic]] antimicrobial therapy prior to sexual intercourse may be administered to patients who have recurrent episodes of cystitis that are associated with sexual activity.
Worldwide, the prevalence of community associated UTI is 7000 per 100,000 persons.[1]
The prevalence of hospital associated UTI is 129, 196 and 24000 per 100,000 persons in the United States, Europe and developing countries, respectively.[1]
The annual incidence of urinary tract infection in women is 1200 per 100,000 persons.
The incidence of asymptomatic bacteriuria in pregnant women is 5900 per 100,000 persons.[2][3]
The incidence of recurrence of urinary tract infection in young healthy women is 25000 per 100,000 persons and there is increase in the recurrent rates with every subsequent infection.[5]
The incidence of pyelonephritis among healthy women is 120 and 30-40 per 100,000 persons in the outpatient and inpatient setting respectively.[6]
The incidence of pyelonephritis in male population is 20 and 10 cases per 100,000 persons in the outpatient and inpatient setting respectively.[7]
The incidence of UTI is higher in sexually active women than postmenopausal women.[8][5][9]
There is high incidence of urinary tract infection in immunocompromised, elderly, diabetic, and individuals with indwelling catheters.[10][11]
Journal Reference
Raas-Rothschild A, Spiegel R (2010 Jan 28). "Mucolipidosis III Gamma". GeneReviews®. PMID20301784. Check date values in: |access-date=, |date= (help); |access-date= requires |url= (help)
↑Czaja, Christopher A., et al. "Population-based epidemiologic analysis of acute pyelonephritis." Clinical Infectious Diseases 45.3 (2007): 273-280.
↑Czaja, Christopher A., et al. "Population-based epidemiologic analysis of acute pyelonephritis." Clinical Infectious Diseases 45.3 (2007): 273-280.
↑Jackson, Sara L., et al. "Predictors of urinary tract infection after menopause: a prospective study." The American journal of medicine 117.12 (2004): 903-911.
↑Nicolle, Lindsay E., et al. "Infectious Diseases Society of America guidelines for the diagnosis and treatment of asymptomatic bacteriuria in adults." Clinical Infectious Diseases (2005): 643-654.
