Mid Urinary Tract Infections

Front 1

What is a urinary tract infection?

Back 1

A significant baceriria in the presence of a constellation of symptoms such as dysuria (painful urination), increased urinary frequency and urgency, suprapubic discomfort and costovertebral angle tenderness

Front 2

What is cystitis?

Back 2

A syndrome involving dysuria, suprapubic tenderness with urinary frequency and urgency

Front 3

What is acute pyelonephritis? What are its clinical symptoms?

Back 3

The syndrome of cystitis accompanied by significant bacteriuria and acute infection of the kidney.

Clinical symptoms: Flank pain, fever, dysuria, urinary urgency and frequency

Front 4

What is a lower UTI?

Back 4

Cystitis, urethritis, prostatitis

Symptoms: Dysuria, urinary urgency and frequency, bladder fullness/discomfort
-Blood urine reported in as many as 10% of cases of UTI in otherwise healthy women

Front 5

What is an upper UTI?

Back 5

Pyelonephritis, intra-renal abscess, perinephric abscess (usually late complications of pyelonephritis)
Rigors indicate bacteremia

Symptoms: Fever, sweating, nausea, vomiting, flank pain, dysuria,
signs and symptoms of dehydration, hypotension

Front 6

What is an uncomplicated UTI?

Back 6

Infection is a structurally and neurologically normal urinary tract. Simple cystitis of short (1-5 day) duration

Front 7

What is a complicated UTI?

Back 7

Infection in a urinary tract with functional or structural abnormalities (ex. indwelling catheters and renal calculi). Cystitis of long duration or hemorrhagic cystitis.

Front 8

What groups are at increased risk of infection?

Back 8

-Neonates
-Prepubertal girls
-Young women
-Older men,
-Individuals with structural abnormalities of the urinary tract
-Immunosuppression

Front 9

Do UTIs occur more in men or women?

Back 9

In neonates, a UTI occurs more often in males; thereafter they occur more frequently in girls and women.

Front 10

What is associated with UTIs in preschool boys?

Back 10

-Serious congenital abnormalities
-Lack of circumcision
-Men are not normally at risk of UTIs until >50yo

Front 11

What is the connection between UTIs and pregnancy?

Back 11

Pregnant women have a 4-10% prevalence of bacteriuria which has been shown to increase the risk of premature delivery, fetal mortality and pyelonephritis in the mother.

Front 12

What is the connection between hospitals and UTIs?

Back 12

In the hospitalized patient, URIs may account for close to 50% of the hospital-acquired infections and are a major cause of gram negative bacteremia and mortality

Front 13

What are the symptoms of UTIs in children?

Back 13

-Younger than 2 yo - enuresis, fever, poor weight gain
-Older than 3 yo - dysuria, lower abdominal pain

Front 14

Explain the urine dip stick

Back 14

he urine dipstick is a leukocyte esterase test that is checking for presence of white blood cells or inflammation. It is also a nitrate test, checking for the presence of bacteria that can reduce nitrate into nitrite. This is only positive in ~25% of the patients.

Front 15

What is the gold standard in UTI diagnosis?

Back 15

Culturing bacteria

Front 16

How do you diagnose a UTI?

Back 16

Urine cultures may not be necessary for a young, sexually active female.
-Urine analysis microscopic examination
-WBC/RBC
-Presence of bacteria
-Urine dipstick test
-Hematuria and proteinuria suggest complicated cystitis or upper tract infection

Front 17

When would you use imaging to determine if the patient has a UTI? What modality?

Back 17

-Children
-US, IVP, CT
-Bacteremic pyelonephritis not responding to therapy
-US, IVP, CT
-Nephrolithiasis or Neurogenic bladder
-US, CT, or IVP with post-voiding films
-Men with 1st or 2nd infection
-Careful prostate exame
-Ultrasound or IVP with post-voidal films

Front 18

What is the leading cause of UTIs in sexually active women?

Back 18

-E. coli (79%)
-S. saprophyticus (11%)
-Klebsiella pneumoniae (3%)
-Proteus mirabilis (2%)
-Enterococcus (2%)

Front 19

What is the leading cause of UTIS in acute uncomplicated pyelonephritis?

Back 19

-E. coli (89%)

Front 20

What are the leading causes of Complicated UTIs?

Back 20

-E.coli (32%)
-Enterococci (22%)
-Ps. aeruginosa (20%)
-S. epidermidis (15%)

Front 21

What are the leading cuases of catheted UTIs?

Back 21

-Candida
-E. coli
-Mixed

Front 22

Describe the hematogenous route

Back 22

-Infection of the renal parenchyma through bacteremia.
-Less common than ascending route
-KIdney is commonly a site of abscess in patients with bacteremia or endoarditis caused by gram positive organisms (S. aureus)
-Infections of kidney with Gram neg bacilli are rare through this route

Front 23

Describe the ascending route

Back 23

-Develops when uropathogens from the fecal flora colonize the vaginal introitus
-Bacteria enter bladder through urethra
-Bacteria in the bladder multiply and ascend up through the ureters to the renal parenchyma

Front 24

What are the factors predisposing to UTI in women?

Back 24

-Short urethra
-Sexual intercourse and lack of post coidal voiding
-Diaphragm, spermicide use
-Estrogen deficiency
-P1 blood group - upper UTI

Front 25

What are the general host factors predisposing to infections?

Back 25

-Extra-renal obstruction
-Posterior urethral valves
-Urethral strictures
-Renal calculi
-Incomplete bladder emptying
-Neurogenic bladder
-Immunocompromised invididuals
-Urinary reflux

Front 26

What are the host defenses to UTI

Back 26

-High urine flow rate
-High voiding frequency
-Urine osmolarity, pH, organic acids
-Urinary inhibitors of bacterial adherence
-Bladder mucopolysaccharides
-SIgA
-Inflammatory response
-Prostatic secretions
-Humoral and cell-mediated immunity

Front 27

What are the bacterial virulence factors?

Back 27

-Type 1 fimbriae (mediate binding to mannosylated glycoproteins on bladder uroepithelial cells, enhance phagocytosis)
-P fimbriae - (bind galactose disaccharide on surface of uroepithelial cells and P1 blood group antigen on RBCs, block phagocytosis)
-Phase variation (downregulate type 1, upregulate type P)
-Flagella
-Production of hemolysin (nutrient release from cells)
-Production of aerobactin iron-: acquisition in the iron-poor environment of the urinary tract

Front 28

What is the treatment for UTI

Back 28

-Lower UTI in a healthy young female: 3 days oral antibiotics
-All other women with lower URI: 5-7 days
-Acute pyelonephritis: Initial therapy + later oral therapy. Total duration: 10-14 days. Repeat urine culture 5-9 days later. Relapsed patients get 2-4 weeks more therapy
-Trimethoprim, co-trimoxazole, and fluoroquinolones are ideal agents since they are effective orally and achieve good urine concentrations and tend not to disturb the anaerobic flora of the gut and the vagina

Acute cystitis in adult men: 7-10 days of treatment
Acute prostatitis from same organisms: 6-12 weeks, 70% cure rate
Non-bacterial prostatosis (chlaymdiae or ureaplasmata): tetracyclines, erythromycins or fluoroquinolones

Front 29

What asymptomatic UTIs should be treated? Which shouldnt?

Back 29

-Pregnant women at high risk for pyelonephritis and premature deliver: culture and treat if positive during 1st and 3rd trimesters
-Individuals with known neurological or structural abnormalities of the urinary system should be treated
-Prophylactic pre-operative treatment of asymptomatic bacteriruia is beneficial to those undergoing urologic surgery

-Asymptomatic bacteriuria with an indwelling catheter should not be treated, but if bacteruria is present 48 hours after removal it should

Front 30

What are the risk factors for recurrent UTIs?

Back 30

-Postmenopausal status
-Diabetes
-Recent antimicrobial use
-Behavioral risk factors
-Frequency of sexual intercourse
-Sperimicide, oral contraceptive use
-New partner
-First UTI <15yo

Front 31

When is antibiotic prophylaxis used

Back 31

->2 symptomatic UTIs in 6 months
->3 symptomatic UTIs in 12 months

Front 32

What is special about candiduria

Back 32

Diabetics and immunocompromised patients may develop it. If it persists 48-72 hours after catheter removal or has fever/leukocytosis then treatment may be warrented. Rule out contamination. Teat with oral fluconzaole or bladder irrigation with amphotericin B

Front 33

Explain the relation of catheters and UTIs

Back 33

-Catheters post surgery up to 7 days will not cause UTIs
-Long term use will result in colonization and infection (8-10% /day)