Management of UTI

by

Osama El-Mishawy,MD

Head of Medicine & Nephrology

Depart. Minia University

Case Study

35-year-old woman has experienced urinary frequency with dysuria for the past 4 days. On physical examination

she has no flank pain or tenderness.

Urinalysis reveals sp. gr. 1014, pH 7.5, no glucose, no protein, no blood, nitrite positive, and many WBC's. She has a serum creatinine of 0.9 mg/dL.

Which of the following is the most likely diagnosis?

A-Lupus nephritis B-Urinary tract lithiasis C- Acute bacterial cystitis

D-PSGN E-Urothelial carcinoma

Case Study

A-Lupus nephritis B-Urinary tract lithiasis

C-Acute bacterial cystitis D-PSGN E-Urothelial carcinoma

(C) CORRECT. These are features of acute

inflammation. There are no casts, because the infection involves the bladder, though such an infection could ascend to produce pyelonephritis. Urinary tract

infections are more common in women because of the shorter urethra

Urinary tract infections

Asymptomatic bacteriuria

Acute cystitis

Acute pyelonephritis

Uncomplicated / complicated UTI

Epidemiology of UTI

UTI is more common in females.(1-2% of young non pregnant women).

40% of females will have a symptomatic UTI in their life

time.

In men: prevalence is 0.04%.

Incidence of UTI increases in old age.(10% of men & 20% of women)

Risk factors for UTI

in females: pregnancy, spermicidal contraceptives, diaphragm, estrogen deficiency, diabetes.

In males:

lack of circumcision, prostatic hypertrophy, catheter.

in both :

old age , obstruction, vesicoureteric reflux, instrumentation, neurogenic bladder, renal transplantation.

Infecting organisms

E.coli Proteus

Klebsiella Pseudomonas

Enterobacter Enterococci

Staphylococci Candida

Pathogenesis of UTI

Host defences:

Urinary bladder is usually resistant to bacterial

colonisation.

Bacteria accessing the bladder are eliminated by:

flushing mechanism

urine inhibitors (PH)

uroepithelial defences (cytokines,PMNs)

Pathogenesis of UTI

Periutheral area & urethra are colonised by bacteria.

Bacteria enter bladder in susceptable host.

Adherence properties enable pathogens to colonise bladder.

Pathogens attach to uroepithelial mucosa secretion of cytokines recruitment of PMNs inflammation.

Pathogens may ascend through ureter to kidney pyelonephritis.

Clinical presentation of UTI

Asymptomatic bacteriuria:

Common in females & elderly.

25% develop symptomatic UTI .

25% clear spontaneously.

Spontaneous cure & reinfection are common.

Cystitis:

Frequency, dysurea , urgency.

Suprapubic discomfort +/- tenderness.

Fever is often absent.

Clinical presentation of UTI

Acute pyelonephritis:

Fever, abdominal pain, vomiting.

Dysuria ,frequency, flank or loin pain.

Flank or loin tenderness.

In elderly: symptoms are often atypical.

Bacteremia is common.

Special situations

UTI in pregnancy:

Asymptomatic bacteriuria occurs in 4-8%.

Of these: 25% develop acute pyelonephritis.

Pyelonephritis in pregnancy predisposes to:

- premature delivery. - low birth weight infant.

- increased newborn mortality.

Special situations

Catheter associated UTI :

Bacteriuria occurs in 10-15% of cathed pts.

All chronicly cathed pts. develop bacteriuria.

Organisms: E.coli, Proteus, Klebsiella, Serratia Pseudomonas, Enterococci, Candida.

Antibiotic resistance is common.

Symptoms are often absent or minimal.

Intermittent cathing reduces infections.

Diagnosis of UTI

Urine dipstick: - leukocyte esterase

- nitrite

Urine microscopy: -WBCs, WBC casts, RBCs - Bacteria ( 1 bact/hpf = significant )

Diagnosis of UTI

Urine culture:

Significant bacteriuria= 100 cfu/ml

Symptoms: 10 cfu/ml = propable infection

(Colony forming unit)

colony-forming unit (CFU) is an estimate of viable bacterial or fungal numbers. Unlike direct microscopic counts where all cells, dead and living, are counted, CFU estimates viable cells.

False negative : antibiotics, antiseptics, urethral syndrome, TB kidney, diuresis.

Natural history of UTI

Treatment of uncomplicated UTI leads to complete resolution and cure.

Recurrences occur in some patients usually within 2-3

months of initial infection.

Recurrent uncomplicated UTI does not lead to chronic renal impairment or failure.

Recurrent complicated UTI may lead to renal failure.

UTI may accelerate progression of underlying renal disease.

Treatment of UTI Acute pyelonephritis:

Mild infections are treated orally. (fluoroquinolones,co-trimoxazole,cefuroxime)

Moderate - severe infections – parenterally trt.

(aminoglycosides, ceftriaxone,aztreonam,tazocin)

Therapy marked decline in bact. count after 48hrs.

Persistent fever, +ve blood culture after 3 days of therapy..suggests obstruction, abscess.

Follow Up urine cultures 2 weeks after end of therapy.

Treatment of UTI

Cystitis:

young females: 3 days of oral therapy (fluoroquinolone,cotrimoxazole,cefuroxime,augm

entin)

In females: symptoms for 7 days or history of previous infection 7 days therapy.

In males : oral therapy for 7-10 days.

Treatment of UTI

Asymptomatic bacteriuria

No urgency to treat – confirm by 2 cultures.

Treatment is indicated in :

- Pregnancy

- Children with VU reflux

- Urinary obstruction

Treatment of UTI

Relapse of infection:

Relapse may be due to : - renal involvement - structural abnormalities - chronic bacterial prostatitis

Relapses need to be treated for 2 weeks.

Obstuction should be corrected .

If uncorrectable obstruction: treatment is prolonged for 4-6 weeks or as required.

The latter group needs Follow Up by monthly cultures and annual assessment of kidneys.

Thank you