Infection & Inflammation

UTI: Definitions & Classification

• Uncomplicated UTI — non-pregnant women with no known anatomical/functional abnormality
• Complicated UTI — all men; pregnant women; or non-pregnant women with functional/anatomical abnormality
• No need to treat asymptomatic UTI unless pregnant or before a urological procedure
• Pyuria without bacteriuria ➡ warrants evaluation for TB, stones, cancer

Treatment — Uncomplicated UTI (Cystitis)

• Women:
  • Fosfomycin 3 g single dose, OR
  • Nitrofurantoin 100 mg BID × 5 days
  • Bactrim 160/800 BID × 3 days
• Men (cystitis):
  • Bactrim 160/800 BID × 7 days, OR
  • Ciprofloxacin 500 mg BID × 10–14 days (complicated UTI)

Bacteriuria, Nitrites & Urease Organisms

• Pyuria = presence of ≥5 WBC or more (per HPF)
• Nitrite positive organisms (nitrate reductase +): 1. E. coli, 2. Klebsiella, 3. Proteus, 4. Enterobacter, 5. Serratia
• Nitrite negative organisms: 1. Pseudomonas, 2. Streptococcus

Urease-producing organisms ➡ struvite stones (MAP)

• Stone-forming (urease +): 1. Staphylococcus (90%) 2. Proteus (90%) 3. Klebsiella 4. Enterobacter 5. Serratia 6. Morganella 7. Pseudomonas 8. Providencia 9. Candida humicola
• Mechanism: urease splits urea → ammonia + bicarbonate ➡ urine alkalinization ➡ promotes MAP (struvite) crystallization

Bacteriuria — Diagnostic Thresholds (MCU)

Setting	Threshold
Asymptomatic	10⁵ CFU/mL
Symptomatic	10² CFU/mL
Catheter sample	5 × 10⁴ CFU/mL
Suprapubic aspiration	Any organism

Persistent / Severe Complicated UTI

• Severe complicated UTI ➡ parenteral antibiotics 14–21 days
• Urological abnormalities causing persistent UTI: 1. Stones, 2. Chronic bacterial prostatitis, 3. Foreign body, 4. Atrophic kidney, 5. Diverticulum, 6. Urachal cyst, 7. Abscess

Approach to Recurrent UTI

• Definition: ≥2 UTIs in 6 months OR ≥3 in 12 months

➡ Hx & PE + UA & culture + PVR

• Positive culture ➡ antimicrobial therapy ➡ repeated infection, same species:
  • Yes (same species) ➡ Bacterial persistence ➡ urological evaluation (CT-U + cystoscopy) ➡ removal of infection focus
  • No ➡ Reinfection ➡ assess risk factors
    • Risk factors present ➡ urological evaluation (CT-U + cysto)
    • No risk factors ➡ related to coitus?
    • Yes ➡ post-coital prophylaxis
    • No ➡ low-dose prophylaxis OR self-start therapy

Prevention & Modifiable Risk Factors

• Cranberry juice (36 mg or 200–750 mL daily) ➡ blocks adherence of pathogens to uroepithelial cells
  • Reduces morbidity + time of recurrent bacteriuria, but risk of recurrence is the same
• Modifiable risk factors for bacterial persistence: check PVR, hydration, constipation
• Postmenopausal ➡ consider vaginal estrogen

Host & Bacterial Factors

• E. coli pili:
  • P pili ➡ adhesion ability ➡ pyelonephritis
  • Type 1 pili ➡ no adhesion
• Urine bacterial growth inhibited by: 1. diluted urine 2. high osmolality 3. low pH

Cystitis — Treatment by Population

Population	First line	Alternative
Healthy women	Fosfomycin 3 g SD, OR Nitrofurantoin 100 BID × 5 days, OR Bactrim 160/800 BID × 3 days	—
Diabetic / recurrent women	Bactrim or Cipro × 7 days	—
Pregnant women	Amoxicillin or Cephalexin	Bactrim & nitro not given
Healthy men	Bactrim or Cipro × 7 days	—

• Avoid Bactrim in pregnancy (1st trimester & 3rd trimester)
• Avoid nitrofurantoin in pregnancy (3rd trimester)
• Avoid Bactrim with warfarin — also Cipro
• Follow-up urine culture after treatment recommended for older women & men

Emphysematous Cystitis

• Cystitis (UTI) with air in the bladder, no recent instrumentation
• Treatment ➡ antibiotics & drainage

Fungal UTI (Candida)

• Candida albicans ➡ sensitive to azole
• Candida glabrata & krusei ➡ Amphotericin
• No need to treat asymptomatic candiduria unless:
  • Neutropenia / immunocompromised, low birth weight infants, or before urological procedure
• Asymptomatic candiduria often resolves with no treatment ➡ just control predisposing risk
  • e.g. remove/exchange Foley, control diabetes

Acute Pyelonephritis

• Triad: fever, chills, flank pain
• Treatment depends on symptoms & improvement
• No sepsis or vomiting ➡ imaging optional; do culture first, treat as outpatient with oral abx (Cipro) × 7–10 days
  • Improved after 72 hr ➡ continue treatment + urine culture on Day 4 of abx + urine culture 10 days off abx
  • No improvement after 72 hr ➡ hospitalize + parenteral abx (Cipro) × 14–21 days + imaging + review culture + drain obstruction or abscess
• Sepsis ➡ imaging + urine culture + blood culture
  • Start parenteral abx (Cipro) × 14–21 days
  • Improved after 72 hr ➡ switch to oral abx + repeat urine culture on Day 4 & Day 10 off abx
  • No improvement after 72 hr ➡ continue parenteral abx, review culture, imaging, drain obstruction or abscess

Indications for Imaging in Pyelonephritis

• 1. Diabetes mellitus, 2. Poor response to treatment (72 hr), 3. Hx of stones, 4. Hx of GU surgery, 5. Risk factor for papillary necrosis

Emphysematous Pyelonephritis

• Caused by gas-forming pathogens
• Risk: DM, high tissue glucose level
• E. coli most common, then Klebsiella & Proteus
• Emergency ➡ fluid resuscitation + broad-spectrum antibiotics + system drainage + control blood glucose
• If patient condition doesn't improve ➡ nephrectomy advised

Renal Abscess

• On CT ➡ low-density fluid-filled mass with rim enhancement
• Treatment:
  • < 3 cm ➡ IV abx, conservative
  • If no improvement, OR > 5 cm ➡ percutaneous drainage

Xanthogranulomatous Pyelonephritis (XGP)

• Definition: unilateral non-functioning kidney with obstructive uropathy, persistent bacteriuria
• Imaging: contracted renal pelvis & dilated calyces with obstructing stone → "bear claw" sign
• Pathology: lipid-laden macrophages
• Investigation: UA & culture + CT + DMSA
• Treatment:
  • Patient with UTI ➡ drain the system & abx
  • Patient free of UTI ➡ nephrectomy
• Organism: E. coli + Proteus

Malakoplakia

• Soft plaque, can affect bladder & kidney
• Cause unknown
• Pathology: von Hansemann cells & Michaelis–Gutmann bodies
• Treatment ➡ long-term abx ± TURBT or nephrectomy

Fournier Gangrene

• Gas-forming bacterial infection in diabetic patient
• Organisms: E. coli, Proteus, Klebsiella, Enterococcus, Candida
• Spreads along dartos, Colles & Scarpa, & Buck's fascia
• Orchidectomy never performed — testis has different (own) blood supply
• Management ➡ 2 regimens:
  1. Carbapenem + Clindamycin
  2. Tazocin + Clindamycin

Interstitial Cystitis (IC)

• Defined as LUTS (similar to OAB) but must have pain or discomfort, also associated with either:
  • Hunner ulcer, OR
  • Glomerulations (cystoscopy ➡ fill bladder to 60–100, should see diffuse glomerulation)
• Exclusion criteria (the following exclude IC): 1. Bladder capacity > 350 mL, 2. Duration < 9 months, 3. Absence of nocturia
• People with IC often also have fibromyalgia
• Evaluation: Hx & PE + UA, cytology & symptoms ,voiding diary & Score (cystoscopy & urodynamics optional)
• Diagnosis by exclusion

IC Management (stepwise)

• 1st line — stress management, patient education, behavioral modification
• 2nd line — physiotherapy, amitriptyline, cimetidine, hydroxyzine, intravesical therapy (DMSO, heparin, lidocaine)
• 3rd line — hydrodistension, fulguration of Hunner lesion
• 4th line — Botox injection
• 5th line — cyclosporine
• 6th line — urinary diversion

Prostatitis

Classification System

Category	Type	Notes
Cat 1	Acute bacterial prostatitis	Acute bacterial infection
Cat 2	Chronic bacterial prostatitis	Chronic infection > 3 months
Cat 3A	Inflammatory prostatitis	Inflammatory CPPS, WBC > 5 in VB3 / post-prostatic massage urine or semen
Cat 3B	Non-inflammatory prostatitis	Non-inflammatory CPPS, no WBC in VB3
Cat 4	Asymptomatic inflammatory	(incidental)

3-Glass Test (EPS & VB3 to differentiate)

Category	WBC	Culture
Cat 2 (chronic bacterial)	+ve in EPS & VB3	+ve in EPS & VB3
Cat 3A (inflammatory)	+ve in EPS & VB3	−ve
Cat 3B (non-inflammatory)	−ve in all	−ve

Acute Bacterial Prostatitis

• Fever, LUTS, tender boggy prostate
• Most common organism: E. coli ➡ Don't do PR (DRE)
• Duration of abx ≈ 4–6 weeks

Chronic Pelvic Pain Syndrome (CPPS)

• History & PE (pelvic floor + DRE) & UA + culture
• Recommended tests: sexual Hx, 2-glass test, cytology, PVR + flow
• Management ➡ Cipro (4 wk) + Tamsulosin (6 wk) + NSAIDs (2 wk)
• CPPS associated with IBS

Prostatic Abscess

• < 2 cm ➡ antibiotics
• > 2 cm ➡ drainage (percutaneous or deroofing)

Epididymitis

• STD suspected (< 35 yr) ➡ Ceftriaxone (250–500 mg IM) + Doxycycline (100 mg PO BID × 10 days)
• Enteric suspected (> 35 yr) ➡ Ceftriaxone (250–500 mg IM) + Levofloxacin (500 mg PO OD × 10 days)

Sexually Transmitted Infections

Vaginitis

Disease	Discharge	Diagnosis	Treatment
Trichomonas vaginitis	Yellow-green, strawberry cervix	NAAT swab	Metronidazole 2 g PO single dose
Bacterial vaginosis	Malodor (fishy), white	Gram stain — clue cells	Metronidazole 500 mg PO BID × 7 days

Chlamydia & N. gonorrhoeae

• Chlamydia ➡ organism not visualized under microscope
• N. gonorrhoeae ➡ Gram −ve diplococci

Approach to Non-Ulcer STDs (Urethritis)

• Hx & PE + UA & culture
• Gram stain of urethral secretion
• NAAT by urethral swab or urine
• Screen for syphilis + HIV + chlamydia in gonorrhea +ve patients

Management Algorithm (Urethritis)

• A. Treat initially for both N. gonorrhoeae + chlamydia
• B. Ceftriaxone (250–500 mg IM) to cover N.G. + Azithromycin (1 g PO once) or Doxycycline (100 mg BID × 7 days) for chlamydia
• C. Symptoms persist even after completion of therapy
• D. Escalation:
  • Azithromycin used before ➡ give Moxifloxacin 400 mg PO OD × 7 days
  • Doxycycline used before ➡ give Azithromycin
  • Sex with woman in highly prevalent area ➡ Metronidazole 2 g PO
• Treat the partner also
• Reiter syndrome ➡ uveitis, arthritis, urethritis — associated with chlamydia (HLA-B27)

Genital Ulcer Disease

Disease	Lesion	Lymphadenopathy	Treatment
Syphilis (T. pallidum)	Painless	Bilateral, painless	Benzathine penicillin G
Lymphogranuloma (chlamydia, assoc. anal)	Painless	Painful, systemic symptoms, appears after lesion	Doxycycline 100 mg BID × 21 days
Genital herpes	Painful, vesicle	Painful, bilateral	Acyclovir 400 mg TID × 7 days
Chancroid (Haemophilus ducreyi)	Painful, ulcer	Painful	Azithromycin 1 g PO, or Ceftriaxone

STD Testing

• Herpes ➡ PCR + Tzanck smear
• Chancroid ➡ PCR + culture
• Lymphogranuloma ➡ chlamydia culture + serology
• Syphilis ➡ ① screen by VDRL, RPR ② confirm by FTA
• All patients +ve with syphilis ➡ screen for other STDs like HIV

Genitourinary Tuberculosis (GU TB)

• Symptoms: vague — fever, malaise, storage symptoms, hematuria, & sterile pyuria
• Most affected GU organ: kidney
• Diagnosis ➡ 3 consecutive early-morning urine samples with acid-fast stain & mycobacterial culture
• Radiographic findings ➡ pipe-stem ureter, thimble bladder