A guide to urological infections

This concise overview encapsulates evidence-based insights and suggestions for preventing and treating urinary tract infections (UTIs) and male accessory gland infections, as outlined in the European Association of Urology (EAU) guideline on urological infections

CREDIT: This is an edited version of an article that originally appeared on Medscape

Designed with primary care in mind, this summary offers relevant information. For comprehensive recommendations pertaining to complex UTIs, catheter-related UTIs, urosepsis, Fournier’s gangrene, and peri-procedural antibiotic prophylaxis, the complete guideline should be consulted.

The adaptation of this guideline has been supervised and executed by Medscape UK. Please note that the EAU Guidelines Office is not accountable for the accuracy of this condensed summary.

Strength of recommendations

Each recommendation is accompanied by an associated strength rating. The strength rating structures are informed by the underlying principles of the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) methodology, although they are not claimed to be a direct application of GRADE.

The potency of each recommendation is indicated by the terms [strong recommendation] or [weak recommendation]. The strength of a recommendation is established through weighing the positive and negative outcomes of different management approaches, the caliber of the evidence (including the level of certainty in the estimates), and the diversity and variability of patient values and preferences.

Asymptomatic of Bacteriuria in Adults

Urinary growth of bacteria in an asymptomatic individual is common and corresponds to a commensal colonisation. Treatment of asymptomatic bacteriuria (ABU) should be performed only in cases of proven benefit for the patient to avoid the risk of selecting antimicrobial resistance and eradicating a potentially protective ABU strain.

Diagnostic Evaluation

Asymptomatic bacteriuria in an individual without urinary tract symptoms is defined by a mid-stream sample of urine showing bacterial growth ≥105 cfu/ml in two consecutive samples in women and in one single sample in men. In a single catheterised sample, bacterial growth may be as low as 102 cfu/ml to be considered representing true bacteriuria in both men and women.

Cystoscopy and/or imaging of the upper urinary tract is not mandatory if the medical history is otherwise without remark.

If persistent growth of urease-producing bacteria is detected, for example, Proteus mirabilias, stone formation in the urinary tract must be excluded. In men, a digital rectal examination must be performed to investigate the possibility of prostate diseases.

Recommendations

Do not screen or treat asymptomatic bacteriuria in the following conditions: [strong recommendation]

• women without risk factors
• patients with well-regulated diabetes
• postmenopausal women
• elderly institutionalised patients
• patients with dysfunctional and/or reconstructed lower urinary tracts
• patients with renal transplants
• patients prior to arthroplasty surgeries
• patients with recurrent UTIs

Screen for and treat asymptomatic bacteriuria prior to urological procedures breaching the mucosa [strong recommendation].

Screen for and treat asymptomatic bacteriuria in pregnant women with standard short course treatment. [weak recommendation].

Uncomplicated cystitis

Uncomplicated cystitis is defined as acute, sporadic, or recurrent cystitis limited to nonpregnant women with no known relevant anatomical and functional abnormalities within the urinary tract or comorbidities.

Diagnostic Evaluation

Clinical Diagnosis

The diagnosis of uncomplicated cystitis can be made with a high probability based on a focused history of lower urinary tract symptoms (dysuria, frequency, and urgency) and the absence of vaginal discharge.

In elderly women genitourinary symptoms are not necessarily related to cystitis.

Recommendations

Diagnose uncomplicated cystitis in women who have no other risk factors for complicated UTIs based on: [strong recommendation]:

• a focused history of lower urinary tract symptoms (dysuria, frequency, and urgency)
• the absence of vaginal discharge

Use urine dipstick testing for diagnosis of acute uncomplicated cystitis [weak recommendation]:

Urine cultures should be done in the following situations:

• suspected acute pyelonephritis
• symptoms that do not resolve or recur within 4 weeks after completion of treatment
• women who present with atypical symptoms
• pregnant women. [strong recommendation]

Recurrent UTIs

Recurrent UTIs (rUTIs) are recurrences of uncomplicated and/or complicated UTIs, with a frequency of at least three UTIs per year or two UTIs in the last 6 months.

Diagnostic Evaluation

• Initial diagnosis of rUTI should be confirmed by urine culture
• Extensive routine diagnostic investigation including cystoscopy and imaging is not routinely recommended as the diagnostic yield is low. However, it should be performed without delay in atypical cases, for example, if renal calculi, outflow obstruction, interstitial cystitis, or urothelial cancer is suspected.

Behavioural Modifications

Women with rUTI should be counselled on avoidance of risks (for example, insufficient drinking, habitual and postcoital delayed urination, wiping from back to front after defecation, douching, and wearing occlusive underwear) before initiation of long-term prophylactic drug treatment, although there is limited evidence available regarding these approaches.

Antimicrobials for Preventing rUTI

Continuous Low-dose Antimicrobial Prophylaxis and Postcoital Prophylaxis

• Antimicrobials may be given as continuous low-dose prophylaxis for longer periods, or as postcoital prophylaxis. There is no significant difference in the efficacy of the two approaches
• After discontinuation of the drug, UTIs tend to re-occur, especially among those who have had three or more infections annually
• The choice of agent should be based on the local resistance patterns. Regimens include nitrofurantoin 50 mg or 100 mg once daily, fosfomycin trometamol 3 g every 10 days, trimethoprim 100 mg once daily, and during pregnancy cephalexin 125 mg or 250 mg or cefaclor 250 mg once daily. Postcoital prophylaxis should be considered in pregnant women with a history of frequent UTIs before onset of pregnancy, to reduce their risk of UTI.

Self-diagnosis and Self-treatment

In patients with good compliance, self-diagnosis and self-treatment with a short course regimen of an antimicrobial agent should be considered. The choice of antimicrobials is the same as for sporadic acute uncomplicated UTI.

Recommendations

• Diagnose rUTI by urine culture [strong recommendation]
• Do not perform an extensive routine diagnostic investigation (for example, cystoscopy, full abdominal ultrasound) in women younger than 40 years of age with rUTI and no risk factors [weak recommendation]
• Advise premenopausal women regarding increased fluid intake as it might reduce the risk of rUTI [weak recommendation]
• Use vaginal oestrogen replacement in postmenopausal women to prevent rUTI [strong recommendation]
• Use immunoactive prophylaxis to reduce rUTI in all age groups [strong recommendation]
• Advise patients on the use of local or oral probiotic containing strains of proven efficacy for vaginal flora regeneration to prevent UTIs [weak recommendation]
• Advise patients on the use of cranberry products to reduce rUTI episodes; however, patients should be informed that the quality of evidence underpinning this is low with contradictory findings [weak recommendation]
• Use D-mannose to reduce rUTI episodes, but patients should be informed of the overall weak and contradictory evidence of its effectiveness [weak recommendation]
• Use methenamine hippurate to reduce rUTI episodes in women without abnormalities of the urinary tract [strong recommendation]
• Use continuous or postcoital antimicrobial prophylaxis to prevent rUTI when non-antimicrobial interventions have failed. Counsel patients regarding possible side effects [strong recommendation]
• For patients with good compliance, self-administered short-term antimicrobial therapy should be considered. [strong recommendation]

Uncomplicated Pyelonephritis

Uncomplicated pyelonephritis is defined as pyelonephritis limited to nonpregnant, premenopausal women with no known relevant urological abnormalities or comorbidities.

Diagnostic Evaluation

Clinical Diagnosis

Pyelonephritis is suggested by fever (>38°C), chills, flank pain, nausea, vomiting, or costovertebral angle tenderness, with or without the typical symptoms of cystitis.

Pregnant women with acute pyelonephritis need special attention, as this kind of infection may not only have an adverse effect on the mother with anaemia, renal and respiratory insufficiency, but also on the unborn child with more frequent preterm labour and birth.

Differential Diagnosis

It is vital to differentiate as soon as possible between uncomplicated and complicated mostly obstructive pyelonephritis, as the latter can rapidly lead to urosepsis. This differential diagnosis should be made by the appropriate imaging technique.

Recommendations

• Perform urinalysis (for example, using the dipstick method), including the assessment of white and red blood cells and nitrite, for routine diagnosis [strong recommendation]
• Perform urine culture and antimicrobial susceptibility testing in patients with pyelonephritis [strong recommendation]
• Perform imaging of the urinary tract to exclude urgent urological disorders [strong recommendation]
• Treat patients with uncomplicated pyelonephritis not requiring hospitalisation with short-course fluoroquinolones as first-line treatment [strong recommendation]
• Do not use nitrofurantoin, oral fosfomycin, and pivmecillinam to treat uncomplicated pyelonephritis. [strong recommendation]

Urethritis

Urethritis can be of either infectious or non-infectious origin. Inflammation of the urethra presents usually with lower urinary tract symptoms and must be distinguished from other infections of the lower urinary tract.

Urethral infection is typically spread by sexual contact.

Diagnostic Evaluation

In symptomatic patients, the diagnosis of urethritis can be made based on the presence of any of the following criteria:

• mucoid, mucopurulent, or purulent urethral discharge
• Gram or methylene-blue stain of urethral secretions demonstrating inflammation
• the presence of >10 polymorphonuclear leukocyte/high power field in the sediment from a spun first-void urine sample or a positive leukocyte esterase test in first-void urine.

Recommendations

• Perform a Gram stain of urethral discharge or a urethral smear to preliminarily diagnose gonococcal urethritis [strong recommendation]
• Perform a validated nucleic acid amplification test (NAAT) on a first-void urine sample or urethral smear prior to empirical treatment to diagnose chlamydial and gonococcal infections [strong recommendation]
• Delay treatment until the results of the NAATs are available to guide treatment choice in patients with mild symptoms [strong recommendation]
• Perform a urethral swab culture, prior to initiation of treatment, in patients with a positive NAAT for gonorrhoea to assess the antimicrobial resistance profile of the infective strain [strong recommendation]
• Use a pathogen directed treatment based on local resistance data [strong recommendation]
• Sexual partners should be treated maintaining patient confidentiality. [strong recommendation]

For more information on other urological infections such as Bacterial Prostatitis and Acute Infective Epididymitis, read the full article on Medscape.