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DIAGNOSIS
HISTORY
Note: Any or all may be present:
- Burning during urination
- Pain during urination (dysuria)
- Urgency (sensation of need to urinate often)
- Frequency
- Sensation of incomplete bladder emptying
- Blood in urine
- Lower abdominal pain or cramping
- Offensive odor of urine
- Nocturia
- Sudden onset of urinary incontinence
- Dyspareunia
PHYSICAL EXAM
- Suprapubic tenderness
- Urethral and/or vaginal tenderness
- Fever or costovertebral angle tenderness indicates upper UTI.
DIFFERENTIAL DIAGNOSIS
- Vaginitis
- Asymptomatic bacteriuria
- STDs causing urethritis or pyuria
- Hematuria from causes other than infection (e.g., neoplasia, calculi)
- Interstitial cystitis
- Psychological dysfunction
DIAGNOSTIC TESTS & INTERPRETATION
Initial Tests (lab, imaging)
- No lab testing is necessary in women with high likelihood of lower UTI based on classic symptoms.
- Urinalysis
- Pyuria (>10 neutrophils/high-power field [HPF])
- Bacteriuria (any amount on unspun urine, or 10 bacteria/HPF on centrifuged urine)
- Hematuria (>5 RBCs/HPF)
- Dipstick urinalysis
- Leukocyte esterase (75-96% sensitivity, 94-98% specificity, when >100,000 colony-forming units [CFU])
- Nitrite tests are useful with nitrite-reducing organisms (e.g., enterococci, S. saprophyticus, Acinetobacter).
- Urine culture: only indicated if diagnosis is unclear or patient has recurrent infections and resistance is suspected. It is neither cost-effective nor usually helpful for lower-tract, uncomplicated UTI.
- Presence of 100,000 CFU/mL of organism indicates infection.
- Identification of a single organism at lower CFU per milliliter likely also represents infection in the presence of appropriate symptoms.
- Suspect a contaminated specimen when culture shows multiple types of bacteria.
- Imaging studies are often not required in most cases of UTI.
Follow-Up Tests & Special Considerations
- In nonpregnant, premenopausal women with symptoms of UTI, positive urinalysis, and no risks for complicated infection, empirical treatment may be given without obtaining a urine culture.
- Dipstick urinalysis may be helpful but not necessary in patients with characteristic symptoms (i.e., high pretest probability).
- Imaging may be indicated for UTIs in men, infants, immunocompromised patients, febrile infection, signs or symptoms of obstruction, failure to respond to appropriate therapy, and in patients with recurrent infections.
- CT scan and MRI provide the most complete anatomic data in adults.
Pediatric Considerations
For infants and children, obtain US; if ureteral dilatation is detected, obtain either voiding cystourethrogram or isotope cystogram to evaluate for reflux.
Diagnostic Procedures/Other
- Urethral catheterization maybe necessary to obtain a urine specimen from children and adults if the voided urine is suspected of being contaminated.
- Suprapubic bladder aspiration or urethral catheterization techniques can be used to obtain specimens from infants.
- Cystourethroscopy can be used for patients with recurrent UTIs and previous anti-incontinence surgery or hematuria (3)[A].
TREATMENT
GENERAL MEASURES
- Maintain good hydration.
- Maintain good hygiene.
- ¼; of women with uncomplicated UTI experience a second UTI within 6 months and ½; at some time during their lifetime.
MEDICATION
First Line
- The urinary tract topical analgesic phenazopyridine 100 to 200 mg TID produces rapid relief of symptoms and should be offered to patients with more than minor discomfort; it is available over the counter. This medication is not a substitute for definitive treatment. This medication also may alter urinalysis but not the urine culture.
- Uncomplicated UTI (adolescents and adults who are nonpregnant, nondiabetic, afebrile, immunocompetent, and without genitourinary anatomic abnormalities)
- Trimethoprim-sulfamethoxazole (TMP-SMZ; Bactrim): 160/800 mg PO BID for 3 days, best where resistance of E. coli strains <20%
- 5-day course of nitrofurantoin or 3-day fluoroquinolone course should be used in patients with allergy to TMP-SMZ and in areas where E. coli resistance to TMP-SMZ >20% (3)[A].
- Fosfomycin (Monurol): 3 g PO single dose (expensive)
- Lower UTI in pregnancy
- Nitrofurantoin (Macrobid): 100 mg PO BID for 7 days
- Cephalexin (Keflex): 500 mg PO BID for 7 days
- Postcoital UTI: single-dose TMP-SMX or cephalexin may reduce frequency of UTI in sexually active women.
- Complicated UTI (pregnancy, diabetes, febrile, immunocompromised patient, recurrent UTIs): Extend course to 7 to 10 days of treatment with antibiotic chosen based on culture results; may begin with fluoroquinolone, TMP-SMX, or cephalosporin while awaiting results (avoid using nitrofurantoin for complicated UTI)
- Fluoroquinolones are not safe during pregnancy and are usually avoided in treatment of children.
- TMP-SMX use in pregnancy is not desirable (especially in 3rd trimester) but is appropriate in some circumstances (3)[A].
Second Line
- Uncomplicated UTI
- Ciprofloxacin: 250 mg PO BID for 3 days; should be reserved for complicated UTIs
- β-Lactams (amoxicillin/clavulanate, cefdinir, cefpodoxime proxetil) for 3 to 7 days
- Chronic UTIs
- Women with recurrent symptomatic UTIs can be treated with continuous or postcoital prophylactic antibiotics. Treatment duration guided by the severity of patient symptoms and by physician and patient preference: Consider 6 months of therapy, followed by observation for reinfection after discontinuing prophylaxis.
- Continuous antimicrobial prophylaxis involves daily administration of low-dose TMP-SMX 40/200 mg or nitrofurantoin 50 to 100 mg, among others.
- Another treatment option is self-started antibiotics.
Pediatric Considerations
Long-term antibiotics appear to reduce the risk of recurrent symptomatic UTI in susceptible children, but the benefit is small and must be considered together with the increased risk of microbial resistance.
ISSUES FOR REFERRAL
Men with uncomplicated UTI and most other patients with complicated UTI should be referred to a urologist for evaluation.
Pediatric Considerations
TI in children, especially <1 year of age, should prompt workup for urinary tract anomalies.
SURGERY/OTHER PROCEDURES
- Urinary tract obstruction with urosepsis requires urgent drainage of the obstructed system.
- Patients with emphysematous pyelonephritis or pyonephrosis may need immediate surgical intervention.
COMPLEMENTARY & ALTERNATIVE MEDICINE
- Preliminary studies indicate that Vaccinium macrocarpon (cranberry) juice may help to prevent and treat UTIs by inhibiting bacterial adherence to the bladder epithelium.
- Cranberry juice may decrease the number of symptomatic UTIs over a 1-year period, particularly for women with recurrent UTIs. The optimal dosage or method of administration (e.g., juice, tablets, or capsules) is still unclear.
INPATIENT CONSIDERATIONS
Inpatient evaluation is reserved for patients with complicated or upper tract UTIs. Majority of UTIs are managed in an outpatient setting.
ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
- First or rare UTI: Young or middle-aged, nonpregnant adult females require no follow up if UTI is clinically cured after 3-day therapy.
- If symptoms persist after 2 to 3 days of therapy, obtain culture/sensitivity and change antibiotic accordingly.
Pregnancy Considerations
UTI during pregnancy always requires culture/sensitivity and usually requires a 7- to 14-day treatment.
Following the treatment of acute infection, pregnant women warrant surveillance urine cultures every trimester. They may receive prophylactic antibiotics for the remainder of pregnancy for recurrent or upper tract disease.
PATIENT EDUCATION
- Although no controlled studies support this intervention, postcoital voiding is commonly advised.
- FamilyDoctor Web site: http://familydoctor.org/familydoctor/en/diseases-conditions/urinary-tract-infections.html
PROGNOSIS
Symptoms resolve within 2 to 3 days of antibiotic treatment in almost all patients.
COMPLICATIONS
- Pyelonephritis or sepsis
- Renal abscess
- Acute urinary outlet obstruction
Pregnancy Considerations
Pregnant females, infants, and young children with cystitis are at higher risk of pyelonephritis.
REFERENCES
11 Kodner CM, Thomas Gupton EK. Recurrent urinary tract infections in women: diagnosis and management. Am Fam Physician. 2010;82(6):638-643.22 Hooton TM. Clinical practice. Uncomplicated urinary tract infection. N Engl J Med. 2012;366(11):1028-1037.33 Zalmanovici Trestioreanu A, Green H, Paul M, et al. Antimicrobial agents for treating uncomplicated urinary tract infection in women. Cochrane Database Syst Rev. 2010;(10):CD007182.
ADDITIONAL READING
- Gupta K, Hooton TM, Naber KG, et al. International clinical practice guidelines for the treatment of acute uncomplicated cystitis and pyelonephritis in women: a 2010 update by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases. Clin Infect Dis. 2011;52(5):e103-e120.
- Jepson RG, Craig JC. Cranberries for preventing urinary tract infections. Cochrane Database Syst Rev. 2008;(1):CD001321.
- Litza JA, Brill JR. Urinary tract infections. Prim Care. 2010;37(3):491-507.
- Mehnert-Kay SA. Diagnosis and management of uncomplicated urinary tract infections. Am Fam Physician. 2005;72(3):451-456.
- Mody L, Juthani-Mehta M. Urinary tract infections in older women: a clinical review. JAMA. 2014;311(8):844-854.
- Stapleton A, Stamm WE. Prevention of urinary tract infection. Infect Dis Clin North Am. 1997;11(3):719-733.
- Williams G, Craig JC. Long-term antibiotics for preventing recurrent urinary tract infection in children. Cochrane Database Syst Rev. 2011;(3):CD001534.
SEE ALSO
Algorithm: Dysuria
CODES
ICD10
- N39.0 Urinary tract infection, site not specified
- N30.90 Cystitis, unspecified without hematuria
- N30.91 Cystitis, unspecified with hematuria
- N30.10 Interstitial cystitis (chronic) without hematuria
- N30.41 Irradiation cystitis with hematuria
- N30.11 Interstitial cystitis (chronic) with hematuria
- N30.81 Other cystitis with hematuria
- N30.80 Other cystitis without hematuria
- N30.31 Trigonitis with hematuria
- N30.30 Trigonitis without hematuria
- N30.20 Other chronic cystitis without hematuria
- N30.01 Acute cystitis with hematuria
- N30.00 Acute cystitis without hematuria
- N30.40 Irradiation cystitis without hematuria
- N30.21 Other chronic cystitis with hematuria
ICD9
- 599.0 Urinary tract infection, site not specified
- 595.9 Cystitis, unspecified
- 595.0 Acute cystitis
- 595.1 Chronic interstitial cystitis
- 595.89 Other specified types of cystitis
- 595.82 Irradiation cystitis
- 595.81 Cystitis cystica
- 595.4 Cystitis in diseases classified elsewhere
- 595.2 Other chronic cystitis
- 595.3 Trigonitis
SNOMED
- 68566005 urinary tract infectious disease (disorder)
- 236620008 Infective cystitis (disorder)
- 197927001 Recurrent urinary tract infection (disorder)
- 197834003 Chronic interstitial cystitis (disorder)
- 4009004 Lower urinary tract infectious disease (disorder)
- 43114002 Chronic trigonitis (disorder)
- 431308006 Acute upper urinary tract infection (disorder)
- 62199007 Acute trigonitis (disorder)
- 68226007 Acute cystitis
- 33655002 Chronic cystitis
CLINICAL PEARLS
- Uncomplicated UTIs cause significant morbidity but generally do not cause renal damage.
- Treatment of uncomplicated UTIs reduces morbidity, but the risk of recurrence stays the same.
- Bacteria originating from intestinal tract cause most UTIs, especially E. coli.
- Imaging studies are not required for most women with UTIs.
- Uncomplicated UTIs should be treated for 3 days (TMP-SMX) or 5 days (nitrofurantoin). All pregnant women with bacteriuria should be treated.