Urinary tract Infections

Epidemiology

In the United States, urinary tract infection is the most common bacterial infection. It has about more than 8 million visits yearly. UTI is more common in women in which 50% will experience it in their lifetime. Women are 6 times more affected than men. Antibiotic is its main treatment. 15% of medicines are made for UTI.

Classifications of UTI:

• Complicated – urinary tract infections are related with a predisposing lesion of the urinary tract; however, this may also refer to all other infections, excluding those in the health, premenopausal adult female.
• Uncomplicated – is an infection in a healthy, premenopausal female who lacks anatomical or functional deviations of the urinary tract. About 75%-90% of most uncomplicated UTIs are due to Escherichia coli and the rest are due to Staphylococcus saprophyticus, Proteus spp., and Klebsiella spp.

Recurrent UTI are either:

• Reinfection – occurs more than 2 weeks after the last UTI and recognized as new uncomplicated UTI.
• Relapse – occurs within 2 weeks of the original infection, and it is considered as a relapse of the original infection. This may be due to unsuccessful treatment of the original infection, structural deviations, or resistant microorganisms.

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Etiology

Lower UTI or refer as cystitis is more common in women than in men. The upper UTI is also refer to as pyelonephritis. The common cause of UTI is different bacteria which is specified below:

Complicated UTI may be caused by the following organisms:

• Gram-negative organisms and
• Enterococcus faecalis

Uncomplicated UTI may be caused by the following organisms:

• Escherichia coli
• Staphylococcus saprophyticus
• Proteus spp.
• Klebsiella spp.

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Pathophysiology 

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Clinical Presentation

Types of UTI	Signs and Symptoms
Lower UTI	Dysuria Urgency Frequency Nocturia Suprapubic heaviness
Upper UTI	Fever Nausea Vomiting Flank pain

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Risk Factors

UTI also comes with different predisposing factors such as the following:

PATIENT	RISK FACTORS
Premenopausal women of any age	·         Diabetes ·         Diaphragm use, especially those with spermicide ·         History of UTI or UTI during childhood ·         Mother or female relatives with history of UTIs ·         Sexual intercourse
Postmenopausal and older adult women	·         Estrogen deficiency ·         Functional or mental impairment ·         History of UTI before menopause ·         Urinary catheterization ·         Urinary incontinence
Men and women with structural abnormalities	·         Extrarenal obstruction associated with congenital anomalies of the ureter or urethra, calculi, extrinsic ureteral compression, or benign prostate hypertrophy ·         Intrarenal obstruction associated with nephrocalcinosis, uric acid nephropathy, polycystic kidney disease, hypokalemic or analgesic nephropathy, renal lesions from sickle cell disease

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Diagnostics

Laboratory Tests	Implications
Urine Analysis	is often used to determine UTIs, and a clean-catch dipstick leukocyte esterase test is a rapid screening test for detecting pyuria with a high sensitivity and specificity for detecting more than 10 WBC/mm3 in urine (Sobel 2014).
Urine Culture	is not suggested for treating acute uncomplicated cystitis. However, for acute pyelonephritis and any type of complicated UTIs, a urine culture should be conducted before empirical therapy to maximize the subsequent specific antibiotic therapy once the susceptible results are obtained.
Basic metabolic panel	A basic metabolic panel is a blood test that measures your sugar (glucose) level, electrolyte and fluid balance, and kidney function. Glucose is a type of sugar your body uses for energy. Electrolytes keep your body’s fluids in balance.
Complete blood count	For upper urinary tract infection, CBC is required by most physician to determine if the infection has not spread to your blood stream.

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Treatment

Category

Probable Organisms

Regimen

Duration of Therapy

Asymptomatic bacteriuria   Positive culture ≥ 100,000 cfu/ml with or without pyuria but without signs and symptoms		This should be treated in pregnant patients. Those who are undergoing urologic procedure in which mucosal bleeding may occur. Neutropenic
o   Uncomplicated o   Cystitis   Signs or symptoms (frequency, urgency, dysuria, suprapubic pain) PLUS pyuria (>10 WBC/hpf) PLUS positive urine culture ≥ 100,000 Uncomplicated = non-pregnant females, no urologic abnormalities, no stones, no catheter	E. coli	1st Line therapy • Nitrofurantoin monohydrate/macrocrystals 100 mg BID x 5 days OR • Trimethoprim-sulfamethoxazole 160/800 mg 1 tablet BID x 3 days (avoid if local resistance > 20%) OR • Fosfomycin trometamol 3-gram single dose   2nd Line therapy • Fluoroquinolones: ciprofloxacin 250 mg BID x 3 days, levofloxacin 250 mg daily x 3 days OR • Guidelines and FDA recommend reserving for other uses than acute uncomplicated cystitis   Beta-lactams (e.g., amoxicillin-clavulanate, cefdinir, cefaclor, cefpodoxime) 3-7 days of treatment • Studies have shown beta-lactams to be less effective than TMP-SMX or fluoroquinolones
o   Uncomplicated o  Pyelonephritis	E. coli	Pyelonephritis (Discharging home from ED) – First Line therapy • Fluoroquinolones – Ciprofloxacin 500 mg BID x 7 days – Levofloxacin 750 mg daily x 5 days • TMP-SMX 1 tablet BID x 14 days • Beta-Lactams – Amoxicillin-clavulanate 875/125 mg 1 tablet BID x 14 days – Cefpodoxime 200 mg BID x 14 days • Dosing also dependent upon renal function
Complicated Signs or symptoms (frequency, urgency, dysuria, suprapubic pain) PLUS pyuria (>10 WBC/hpf) PLUS positive urine culture ≥ 100,000 Complicated = male, possible stones, urologic abnormalities, neurogenic bladder * Gonorrhea and Chlamydia should be suspected in a sexually active male with a UTI (refer to Grady STD Guidelines for treatment options)	E. coli	First Line: Cefuroxime 500 mg PO q12h   Second Line: Ciprofloxacin 500 mg PO q12h	7 days

·         Urinary Tract Infection in Men ·         Prostatitis	E. coli, but the spectrum of pathogens is more variable for CBP, including E. coli, E. faecalis, K. pneumoniae, P. mirabilis, P. aeruginosa, S. aureus, and streptococcal spp. (Grabe 2015).	The presence of fever with symptoms of cystitis in men may indicate acute bacterial prostatitis (ABP).   When symptoms persist for more than 3 months, chronic bacterial prostatitis (CBP) occurs. Most men with CBP have a condition called chronic pelvic pain syndrome. Four main symptoms of CBP and chronic pelvic pain syndrome are urogenital pain, lower urinary tract symptoms including voiding or storage symptoms, psychological issues, and sexual dysfunction (Rees 2015).	7 days
·         Urinary Tract Infection in Pregnancy	E. coli	Pregnant women should have the treatment for UTI even if they asymptomatic   • Urine culture with ≥ 105 CFU/mL (≥ 104 CFU/mL if group B Streptococcus)   -Outpatient therapy • Nitrofurantoin (Class B) • Beta-Lactams (Class B) -Inpatient therapy • Ceftriaxone (Class B) • Cefepime (Class B) – reserve for history of previous resistance • Piperacillin-Tazobactam (Class B) – reserve for history of previous resistance	5 Days
·         Catheterized Patients   Patients with urinary catheter is prone to acquire bacteria that may lead to UTI.	Proteus spp., M. morganii, and P. stuartii	Individuals symptomatic with CA-UTI are treated similarly to those with acute complicated cystitis in the absence of upper tract symptoms or complicated pyelonephritis if upper tract symptoms are present (Sobel 2014) A urine culture should be obtained before initiation of antibiotic therapy, if possible, from a newly placed catheter because the bacterial less useful (Hooton 2010). In addition, an indwelling catheter that has been in place for 7 days or longer should be removed or replaced before initiating antibiotics (Grabe 2015).	5-7 days