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'''For patient information click [[{{PAGENAME}} (patient information)|here]]'''
'''For patient information click [[{{PAGENAME}} (patient information)|here]]'''
{{Urinary tract infection}}
{{Urinary tract infection}}
{{CMG}}; {{AE}} {{USAMA}}
{{CMG}}; {{AE}} {{USAMA}}  


{{SK}} UTI
{{SK}} UTI

Revision as of 01:34, 17 October 2020

https://https://www.youtube.com/watch?v=IE_ywuQoJSg%7C350}}


Resident
Survival
Guide

For patient information click here

Urinary Tract Infection Microchapters

Patient Information

Overview

Classification

Pyelonephritis
Cystitis
Prostatitis
Urethritis
Asymptomatic bacteriuria

Causes

Differential Diagnosis

Treatment

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Usama Talib, BSc, MD [2]

Synonyms and keywords: UTI

Overview

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. Depending on the site of the infection, a urinary tract infection can be classified as either upper or lower UTI. Lower UTI includes urethritis, prostatitis, asymptomatic bacteriuria, and cystitis (bladder infection), where as upper UTI may include pyelonephritis (infection of the kidneys) and rarely urethritis (infection of the ureters). Each subtype of urinary tract infection can also be subclassified 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. Pyelonephritis and cystitis result mostly from ascending infections from the urethra (urethritis) but can also result from descending infections such as hematogenous spread, or by the lymphatic system. The condition more often affects women, but can affect either gender and all age groups. The pathogenesis of a complicated UTI may include obstruction and stasis of urine flow.[1] 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. Diabetes, Crohn's disease, iatrogenic causes, endometriosis, pelvic inflammatory disease, urinary obstruction, and bladder incontinence are some risk factors for acquiring a urinary tract infection. A thorough physical exam is very helpful in differentiating upper from lower urinary tract infections. Patients with an uncomplicated urinary tract infections are usually well–appearing. The symptoms may include abnormal urine color (cloudy), blood in the urine, frequent urination or urgent need to urinate, dysuria, pressure in the lower pelvis or back, suprapubic pain, flank pain, back pain, fever, nausea, vomiting, and chills.[2] Urinalysis and urine culture are very helpful laboratory tests in diagnosing a urinary tract infection. Pyuria and either white blood cells (WBCs) or red blood cells (RBCs) may be seen on urinalysis. Escherichia coli ("E. coli"), a bacterium found in the lower gastrointestinal tract is one of the most common culprits. The individual infection must be differentiated from various causes of dysuria such as cystitis, acute pyelonephritis, urethritis, prostatitis, vulvovaginitis, urethral strictures or diverticula, benign prostatic hyperplasia and neoplasms such as renal cell carcinoma and cancers of the bladder, prostate, and penis. Antimicrobial therapy is indicated in case of a symptomatic UTI.[3][4] 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, involve and infect other parts of the urinary tract, hematuria, and rarely renal failure. Prognosis is generally good for lower UTIs.[5] The treatment of a UTI depends on the type of the disease, the disease course (acute uncomplicated versus complicated), history of the individual, and the rates of drug resistance in the community. Preventative measures to avoid a UTI include abstinence, being faithful, using a condom, using barrier contraception during sexual intercourse, urinating after intercourse, increasing fluid intake and frequency of urination, and use of estrogen among postmenopausal women.

Historical Perspective

Urinary symptoms and the use of herbal remedies for their treatment was described in ancient China as far back as 3000 BC. Between 460 to 375 BC, Hippocrates described signs, symptoms and etiology of several urinary diseases including UTI in ancient Greece.

Further developments were made over the centuries but an infectious cause for the symptoms was not recognized until the 19th century. Chemotherapeutic agents such as hexamine, vaccines, bacteriophages, and antitoxins were used with limited success in the early 20th century. It was only till 1937 that Sulfanilamide was discovered which led to further development and use of antimicrobial therapy as treatment. [6]

Classification

Urinary tract infections can be classified as follows:

Anatomical Classification

 
 
 
 
 
 
 
 
 
 
 
 
Urinary tract infections
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Upper UTI
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Lower UTI
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Pyelonephritis
 
 
Cystitis
 
 
 
 
 
 
 
Prostatitis
 
 
 
Urethritis
 
 
 
 
 
Asymptomatic bacteriuria
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
• Acute uncomplicated
• Acute complicated
• Chronic
•Emphysematous
• Xantho-granulomatous
 
 
• Acute uncomplicated
• Complicated
•Recurrent/chronic
 
 
 
 
 
 
 
• Acute bacterial
• Chronic bacterial
• Chronic inflammatory
• Chronic non-inflammatory
•Asymptomatic
 
 
 
 
 
 
 
 
 

Classification Based on Symptoms

This classification is primarily used to estimate duration of antibiotic treatment.[7]

 
 
 
UTI
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Fever > 99.9 F OR
Flank pain or CVA tenderness with pyuria OR
Fever with pyuria OR
Sepsis OR
• Systemic signs such as chills, rigors, fatigue OR
• UTI in men OR
• Anatomical renal defects OR
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Present (anyone)
 
 
 
Absent
 
 
 
 
 
 
 
 
 
 
 
 
Treat as complicated UTI
• 5 - 14 days based on choice of antibiotics
 
 
 
Treat as uncomplicated UTI
• 5 days

Pathophysiology

Colonization with ascending spread is the most common mechanism of urinary tract infections. The urinary tract is normally sterile. The enteric pathogen inhabiting the periurethral area ascend into the bladder through urethra. Most common cause of majority of UTIs are some E. coli serotypes. Followed by attachment and penetration of uroepithelium, bacteria continue to divide and can also form biofilms. The pathogen can ascend into the kidneys via ureters once sufficient colonization has occurred. Ureteric peristalsis may also be affected by toxins produced by bacteria. Once they reach the renal parenchyma, it can result in pyelonephritis and even acute kidney injury. Certain risk factors predispose to ascension of pathogen into the bladder. These include Reduced urine flow because of incomplete bladder emptying due to outflow obstruction (malignancy, BPH, urethral strictures etc), neurological disorders and voiding dysfunction

Urinary catheterization, fecal or urinary incontinence which facilitate ascent of pathogens. With urinary catheterization, extraluminal infection is more common than intraluminal infection. Extraluminal infection occurs when bacteria ascend along the biofilm that forms around the catheter in ureter and are introduced into the bladder. Intraluminal infection occurs due to drainage failure leading to urinary stasis, or due to contamination of collection bag.

Factors predisposing to periurethral colonization, e.g., sexual activity, use of spermicide, antibiotic use and low estrogen levels.

Hematogenous spread is an uncommon mechanism and is mostly seen in elderly, neonates and immunocompromised. The most common involved pathogens are Staphylococcus aureus, Candida and Mycobacterium tuberculosis.

Causes

The various causes of urinary tract infections include:

Common Pathogens Pyelonephritis Cystitis Urethritis Prostatitis Asymptomatic Bacteriuria
Ecoli*[8][9][10][11] + (70%) + (78.6%) + (58%) + (80%)
Klebsiella[12] + + + +
Proteus[13] + + + +
Neisseria gonorrhoeae[14] + (21.6%) +
Pseudomonas[15] + + + +
Staphylococcus + + + +
Chlamydia trachomatis[16][17][18] + + + (20–30%) +
Mycoplasma[19][20] + +
Trichomonas[21][22][23] + + + +

*Ecoli is the most common cause of all urinary tract infections[24]

Epidemiology and Demographics

Urinary tract infections are one of the most common infections seen in community and hospital based settings. Majority of community acquired UTIs are cases of uncomplicated bacterial cystitis in women. Approximately 25 to 40% of women in the US between ages 20 to 40 have had a UTI. Urinary tract infections are also common in post menopausal women due to various factors including incomplete bladder emptying( due to uterine/bladder prolapse), low estrogen levels, loss of vaginal flora of H2O2-producing lactobacillus and presence of chronic medical illnesses like diabetes mellitus. Complicated UTIs are usually in hospital settings and in association with catheter use. It is estimated that there are more than one million catheter related urinary tract infections per year in the US.

Risk Factors

Some host factors also play a role in determining susceptibility to the development of UTIs. These include anatomical factors like urethral length, integrity of the ureterovesical junction and extent of bladder emptying. Some biochemical properties of urine like acidic pH, presence of organic acids in urine, high osmolality and high urea concentration can be protective against urinary tract infection. Alterations in host defense mechanisms due to aging and conditions like Diabetes mellitus, HIV, pregnancy can predispose to development of urinary tract infections. Structural and anatomical abnormalities of the urinary tract also increase the risk of developing urinary tract infections. Duration of catheterization is also an important factor and longer duration increases risk of developing urinary tract infection.

Screening

Initial screening for bacteriuria is recommended before sending sample for microbiologic analysis. Screening methods include dipstick tests for detecting presence of nitrites, microscopic analysis, and Gram stain of urine. Urine dipstick test is simple and quick but lacks sensitivity. Screening is only recommended in pregnant women to detect presence of asymptomatic bacteriuria. Presence of asymptomatic bacteriuria is seen in 5 to 10% of all pregnant women, especially those from low socioeconomic background and those with diabetes mellitus.

Natural history, complications and prognosis

Simple lower UTIs can resolve without treatment especially in young women. Antibiotic therapy lessens duration, severity of symptoms and reduces the risk of involvement of upper urinary tract. Some features are associated with a prolonged duration of illness, such as previous symptoms, more severe baseline symptoms, urinary frequency and history of somatization. [25] A quarter of women with cystitis will experience recurrence even with treatment. Other factors associated with unfavorable prognosis include old age, anatomic or structural urinary tract abnormalities, sickle cell anemia, diabetes mellitus, associated malignancy, recent hospitalization, antibiotic therapy or urinary tract instrumentation. Complications of urinary tract infections include urosepsis, septic shock, abscess formation, stricture formation, fistula formation, hydronephrosis, pyonephrosis and renal failure

Differential Diagnosis

Urinary tract infections should be differentiated from one another and from various other diseases:

Diseases Symptoms Physical Examination Diagnostic tests Past medical history Other Findings
Hematuria Pyuria Frequency Urgency Dysuria Fever Tenderness Discharge Inguinal Lymphadenopathy Urinalysis Urine Culture Gold Standard
Differentiating amongst different types of urinary tract infections:
Pyelonephritis + + + + Flank or costovertebral angle + + Identifies causative bacteria Urine culture
Cystitis + + + + + + Suprapubic + >100,000CFU/mL Urine culture
Urethritis + + + Urethral discharge + Gram stain & mucoid or purulent discharge
Prostatitis + + + + + Identifies causative bacteria (in bacterial subtypes) Urine culture
Diseases Symptoms Physical Examination Diagnostic tests Past medical history Other Findings
Hematuria Pyuria Frequency Urgency Dysuria Fever Tenderness Discharge Inguinal Lymphadenopathy Urinalysis Urine Culture Gold Standard
Differentiating UTIs from other diseases:
Vulvovagintis + + Vaginal discharge  + Gram stain & culture of discharge
  • Number and type of sexual partners (new, casual, or regular)
  • Prior STDs
  • Previous history of symptomatic BV in female partner (in homosexual women)
Cervicitis + + + Cervical Endocervical exudate Culture for gonococcal cervicitis
Epididymitis + + + + + Testicular & suprapubic +/– urethral discharge + + Culture
Syphilis

(STD)

+/– + Darkfield microscopy
BPH + + + + DRE

& Serum PSA

Neoplasms + + + +/– + Imaging and biopsy
Diseases Symptoms Physical Examination Diagnostic tests Past medical history Other Findings
Hematuria Pyuria Frequency Urgency Dysuria Fever Tenderness Discharge Inguinal Lymphadenopathy Urinalysis Urine Culture Gold Standard

Treatment

References

  1. Hooton TM (2000). "Pathogenesis of urinary tract infections: an update". J Antimicrob Chemother. 46 Suppl A: 1–7. PMID 10969044.
  2. Colgan R, Williams M (2011). "Diagnosis and treatment of acute uncomplicated cystitis". Am Fam Physician. 84 (7): 771–6. PMID 22010614.
  3. Bremnor JD, Sadovsky R (2002). "Evaluation of dysuria in adults". Am Fam Physician. 65 (8): 1589–96. PMID 11989635.
  4. Kurowski K (1998). "The woman with dysuria". Am Fam Physician. 57 (9): 2155–64, 2169–70. PMID 9606306.
  5. 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
  6. Nickel JC (2005). "Management of urinary tract infections: historical perspective and current strategies: Part 1--Before antibiotics". J Urol. 173 (1): 21–6. doi:10.1097/01.ju.0000141496.59533.b2. PMID 15592018.
  7. Peterson J, Kaul S, Khashab M, Fisher AC, Kahn JB (2008). "A double-blind, randomized comparison of levofloxacin 750 mg once-daily for five days with ciprofloxacin 400/500 mg twice-daily for 10 days for the treatment of complicated urinary tract infections and acute pyelonephritis". Urology. 71 (1): 17–22. doi:10.1016/j.urology.2007.09.002. PMID 18242357.
  8. R. M. Echols, R. L. Tosiello, D. C. Haverstock & A. D. Tice (1999). "Demographic, clinical, and treatment parameters influencing the outcome of acute cystitis". Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. 29 (1): 113–119. doi:10.1086/520138. PMID 10433573.
  9. Manuel Etienne, Pascal Chavanet, Louis Sibert, Frederic Michel, Herve Levesque, Bernard Lorcerie, Jean Doucet, Pierre Pfitzenmeyer & Francois Caron (2008). "Acute bacterial prostatitis: heterogeneity in diagnostic criteria and management. Retrospective multicentric analysis of 371 patients diagnosed with acute prostatitis". BMC infectious diseases. 8: 12. doi:10.1186/1471-2334-8-12. PMID 18234108.
  10. James B. Hill, Jeanne S. Sheffield, Donald D. McIntire & George D. Jr Wendel (2005). "Acute pyelonephritis in pregnancy". Obstetrics and gynecology. 105 (1): 18–23. doi:10.1097/01.AOG.0000149154.96285.a0. PMID 15625136.
  11. Rebecca E. Watts, Viktoria Hancock, Cheryl-Lynn Y. Ong, Rebecca Munk Vejborg, Amanda N. Mabbett, Makrina Totsika, David F. Looke, Graeme R. Nimmo, Per Klemm & Mark A. Schembri (2010). "Escherichia coli isolates causing asymptomatic bacteriuria in catheterized and noncatheterized individuals possess similar virulence properties". Journal of clinical microbiology. 48 (7): 2449–2458. doi:10.1128/JCM.01611-09. PMID 20444967.
  12. R. M. Echols, R. L. Tosiello, D. C. Haverstock & A. D. Tice (1999). "Demographic, clinical, and treatment parameters influencing the outcome of acute cystitis". Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. 29 (1): 113–119. doi:10.1086/520138. PMID 10433573.
  13. R. M. Echols, R. L. Tosiello, D. C. Haverstock & A. D. Tice (1999). "Demographic, clinical, and treatment parameters influencing the outcome of acute cystitis". Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. 29 (1): 113–119. doi:10.1086/520138. PMID 10433573.
  14. Stephanie N. Taylor, Oliver Liesenfeld, Rebecca A. Lillis, Barbara A. Body, Melinda Nye, James Williams, Carol Eisenhut, Edward W. 3rd Hook & Barbara Van Der Pol (2012). "Evaluation of the Roche cobas(R) CT/NG test for detection of Chlamydia trachomatis and Neisseria gonorrhoeae in male urine". Sexually transmitted diseases. 39 (7): 543–549. doi:10.1097/OLQ.0b013e31824e26ff. PMID 22706217.
  15. Allan Ronald (2002). "The etiology of urinary tract infection: traditional and emerging pathogens". The American journal of medicine. 113 Suppl 1A: 14S–19S. PMID 12113867.
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  17. J. Dimitrakov, V. Ganev, T. Zlatanov, I. Detchev, A. Horvat, S. Kirov, I. Vatchkova & D. Dimitrakov (1998). "PCR studies on the presence of Chlamydia trachomatis in the upper urinary tract of patients with obstructive pyelonephritis". Folia medica. 40 (3): 24–28. PMID 10658351.
  18. Matthew J. Perkins & Catherine F. Decker (2016). "Non-gonococcal urethritis". Disease-a-month : DM. 62 (8): 274–279. doi:10.1016/j.disamonth.2016.03.011. PMID 27107783.
  19. Iu L. Naboka, L. I. Vasil'eva, M. I. Kogan, I. A. Gudima & I. Iu Suchkov (2009). "[Microbial associations defecting in children with chronic pyelonephritis]". Zhurnal mikrobiologii, epidemiologii, i immunobiologii (5): 8–12. PMID 20063785.
  20. Iu L. Naboka, L. I. Vasil'eva, M. I. Kogan, I. A. Gudima & I. Iu Suchkov (2009). "[Microbial associations defecting in children with chronic pyelonephritis]". Zhurnal mikrobiologii, epidemiologii, i immunobiologii (5): 8–12. PMID 20063785.
  21. Template:Hoffman, David J., et al. "Urinary tract infection with Trichomonas vaginalis in a premature newborn infant and the development of chronic lung disease." Journal of perinatology 23.1 (2003): 59-61.
  22. L. SYLVESTRE, M. BELANGER & Z. GALLAI (1960). "Urogenital trichomoniasis in the male: review of the literature and report on treatment of 37 patients by a new nitroimidazole derivative (Flagyl)". Canadian Medical Association journal. 83: 1195–1199. PMID 13774369.
  23. Template:Kuberski, Tim. "Trichomonas vaginalis associated with nongonococcal urethritis and prostatitis." Sexually transmitted diseases 7.3 (1979): 135-136.
  24. Matthew J. Perkins & Catherine F. Decker (2016). "Non-gonococcal urethritis". Disease-a-month : DM. 62 (8): 274–279. doi:10.1016/j.disamonth.2016.03.011. PMID 27107783.
  25. Little P, Merriman R, Turner S, Rumsby K, Warner G, Lowes JA | display-authors=etal (2010) Presentation, pattern, and natural course of severe symptoms, and role of antibiotics and antibiotic resistance among patients presenting with suspected uncomplicated urinary tract infection in primary care: observational study. BMJ 340 ():b5633. DOI:10.1136/bmj.b5633 PMID: 20139213