URINARY TRACT INFECTION IN FEMALES

URINARY TRACT INFECTION IN FEMALES - Barry D.Weiss, MD
BASICS
DESCRIPTION
• Inflammation of the bladder mucosa
• This topic refers primarily to infectious cystitis; other urinary tract infections (UTIs) are discussed elsewhere.
• System(s) Affected: Renal/Urologic
• Synonym(s): Cystitis
GENERAL PREVENTION
• Maintain good hydration.
• Women with frequent or intercourse-related UTI should empty bladder immediately before and following intercourse and consider postcoital antibiotic treatment.
• Avoid feminine hygiene sprays and scented douches.
• Wipe urethra from front to back.
EPIDEMIOLOGY
• Predominant age: Young adults and older
• Predominant sex: Female only (for this discussion)
Incidence
Accounts for 7 million doctor visits a year
Prevalence
• ~3-8% of women have bacteriuria at any given time.
• ~30% of females have at least one UTI.
RISK FACTORS
• Previous UTI
• Diabetes mellitus
• Pregnancy
• More frequent or vigorous sexual activity than usual
• Use of spermicides or diaphragm
• Underlying abnormalities of the urinary tract, such as tumors, calculi, strictures, incomplete bladder emptying
ETIOLOGY
Acute infection, usually with Gram-negative bacteria (Escherichia coli in >90% of uncomplicated cystitis)
ASSOCIATED CONDITIONS
Described under "Risk Factors"
ALERT
Geriatric Considerations
• Elderly are more apt to have underlying urinary tract abnormality.
• Acute UTI is sometimes associated with incontinence or mental status changes in the elderly.
Pediatric Considerations
UTI in children, especially in those 1 year of age should prompt workup for urinary tract anomalies.


DIAGNOSIS
SIGNS AND SYMPTOMS
Note: Any or all may be present.
• Burning during urination
• Pain during urination
• Urgency (sensation of need to urinate frequently)
• Frequency
• Sensation of incomplete bladder emptying
• Blood in urine
• Lower abdominal pain or cramping
• Offensive odor of urine
• Nocturia
TESTS
Some recent research suggests the most cost-effective approach is empiric treatment without lab tests in nonpregnant premenopausal women with symptoms of UTI and no risks for complicated infection.
Lab
• Urinalysis demonstrating pyuria (>10 neutrophils/high power field [HPF] on microscopic exam). Leukocyte esterase dipsticks are also useful for detecting pyuria, but fail to detect pyuria in up to 20% of patients, and false positives occur from vaginal leukocytes.
• Urinalysis demonstrating bacteriuria (any amount on unspun urine, or 10 rod-shaped bacteria/HPF on centrifuged urine). Nitrite dipsticks are also useful (and 94% specific), but fail to detect bacteriuria in 30-50% of patients. Nitrite dipsticks may be negative in patients who do not eat meat.
• Urine culture demonstrating growth of single species of bacteria. Suspect contaminated specimen when culture shows multiple types of bacteria.
• Classic symptoms in nonpregnant young adult female with first episode of UTI require no urine culture for diagnosis. Obtain urinalysis and culture in other age groups, if it is a repeat episode, if the patient is pregnant, or if the symptoms are not classic.
Imaging
For all infants; may be indicated for older patients with recurrent infections
• Ultrasound imaging is the 1st-choice test.
• For infants and children, obtain ultrasound; if ureteral dilation is detected, obtain either voiding cystourethrogram or isotope cystogram to detect reflux.
Diagnostic Procedures/Surgery
• Suprapubic bladder aspiration or urethral catheterization to obtain urine specimen from infants
• Urethral catheterization to obtain urine specimen from children and adults if voided urine is suspected of being contaminated
DIFFERENTIAL DIAGNOSIS
• Vaginitis
• Sexually transmitted diseases causing urethritis or pyuria
• Hematuria from causes other than infection (e.g., neoplasia, calculi)
• Interstitial cystitis
• Psychologic dysfunction
TREATMENT
STABILIZATION
Outpatient treatment, except for complicated or upper tract infections
GENERAL MEASURES
• Maintain good hydration.
• 1/4 of women with simple UTI experience a second UTI within 6 months, and 1/2 at some time during their lifetime. Patients with multiple recurrent UTI and no underlying urinary tract abnormality may receive long-term prophylactic antibiotic treatment. Trimethoprim-sulfamethoxazole (TMP-SMX) and nitrofurantoin are commonly used.
• Patients with chronic indwelling urinary catheters always have colonization of urine, usually with multiple bacterial species. This should not be treated unless symptomatic with fever, sepsis, or other systemic symptoms.
• Preliminary studies indicate that Vaccinium macrocarpon (cranberry juice) may help prevent and treat UTIs by inhibiting bacterial adherence to the bladder epithelium.
• UTI during pregnancy always requires culture/sensitivity and usually requires a 10-14-day treatment. Following the treatment of acute infection, pregnant women often receive prophylactic antibiotics for the remainder of pregnancy.
Diet
No special diet
Activity
Avoid sexual intercourse when symptoms are present.
ALERT
Elderly may have bacteriuria without symptoms; generally this does not require treatment, if the urinary tract is otherwise normal.
MEDICATION (DRUGS)
• 1st, rare, or infrequent UTIs in older children, adolescents, and adults who are nonpregnant, nondiabetic, afebrile, nonimmunocompromised, and have no abnormality of the urinary tract (i.e., uncomplicated)
- 3-day treatment with fluoroquinolone or TMP-SMX. Increasing resistance being reported to TMP-SMX. It is the preferred treatment if local sensitivity patterns indicate low resistance rates.
- New studies show 3-day therapy may be used in children.
• Postcoital: Single-dose TMP-SMX or cephalexin may reduce frequency of UTI in sexually active women.
• Pregnant patients: 10-14-day or longer treatment with pregnancy-safe antibiotic chosen based on culture/sensitivity results. May begin with cephalosporin, amoxicillin, or other antibiotic while awaiting culture/sensitivity results.
• All other patients: 10-14-day treatment with antibiotic chosen based on culture/sensitivity results. May begin with fluoroquinolone, TMP-SMX, cephalosporin, or other antibiotic while awaiting culture/sensitivity results.
• Contraindications
- Refer to the manufacturer's literature.
- Fluoroquinolones are not safe during pregnancy or for treatment of children.
- TMP-SMX use in pregnancy is not desirable (especially in the 3rd trimester), but is appropriate in some circumstances.
• Precautions: Refer to the manufacturer's literature.
• Significant possible interactions: Refer to the manufacturer's literature.
• Change the antibiotic if it is indicated by the culture/sensitivity results.
FOLLOW-UP
PROGNOSIS
Symptoms resolve within 2-3 days after starting a treatment in almost all patients.
COMPLICATIONS
• Pyelonephritis or sepsis
• Renal abscess
• Acute urinary outlet obstruction
ALERT
Infants and young children with cystitis are at higher risk of pyelonephritis.
PATIENT MONITORING
• 1st or rare UTI: In young or middle age, nonpregnant adult females require no follow-up if cured after 3-day therapy. If not resolved within 2-3 days, obtain culture/sensitivity and change antibiotic accordingly.
• All other patients should have post-treatment urine culture to document eradication of infection.
REFERENCES
1. Barry HG, Ebell MH, Hickner J. Evaluation of suspected urinary tract infection in ambulatory women: A cost-utility analysis of office-based strategies. J Fam Pract. 1997;44:49-60.
2. Bent S, et al. Does this woman have an acute uncomplicated urinary tract infection. JAMA. 2002;287:2701-2710.
3. Ebell MH, Barry NC. Urinary tract infection. In: Weiss BD, ed. 20 Common Problems in Primary Care. New York, NY: McGraw-Hill; 1999.
4. Gupta K, Scholes D, Stamm WE. Increasing prevalence of antimicrobial resistance among uropathogens causing acute uncomplicated cystitis in women. JAMA. 1999;281:736-738.
5. Huang ES, Stafford RS. National patterns in the treatment of urinary tract infections in women by ambulatory care physicians. Arch Intern Med. 2002;162:41-47.
6. Stamm WE, Hooton T. Management of urinary tract infections in adults. N Engl J Med. 1993;329:1328-1334.
MISCELLANEOUS
See also: Pyelonephritis