UTIs Flashcards
What is considered the upper urinary tract?
the kidneys and the ureters
What is considered the lower urinary tract?
the bladder and the urethra and prostate in male anatomy
What is the significance of UTIs in the US?
most common bacterial infection in US people seek medical care for, costs $1 billion in health costs/year, and SIGNIFICANTLY impacts women
What is bacteriuria?
bacteria in the urine
What is significant bacteriuria?
numbers of bacteria voiding in urine that exceeds usual number due to contamination
What is dysuria?
pain when peeing
What is pyuria?
when pus or white blood cells present in urine
What is hematuria?
when red blood cells are in the urine
What is cystitis?
an infection of the bladder
What is urethritis?
an infection of the urethra
What is prostatitis?
an infection of the prostate
What is pyelonephritis?
an infection of the kidneys/upper urinary tract
What is the most common UTI?
1 case pyelonephritis to 28 cases of cystitis
What is an uncomplicated UTI?
infection in structurally and neurologically normal urinary tract
What is a complicated UTI?
infection in urinary tract with abnormalities (obstruction, catheter, anatomic, pregnancy, etc.)
Who do UTIs usually affect?
far more likely in females (90%)
What do females get UTIs easier?
the female urethra is shorter than the male and the anus is closer to the vagina on females
What factors can increase the risk of UTI in females?
sexual intercourse, diaphragm and douche use, use of spermicides and soaps, pregnancy, and menopause
About how many women will experience at least one UTI in their lifetime?
50-60%
What are the risk factors for male UTIs?
age is the biggest risk factor, prostate disease (less likely to have secretions that prevent infection)
What are the risk factors for UTIs in children?
low flow conditions due to incomplete voiding, reflux, or structural abnormalities; males up to 3 months = common; lack of circumcision
What are the risk factors for UTIs in the eldery?
increased instrumentation, bladder may not empty or fecal incontinence
What are human risk factors for UTI?
urethral catheterization, obstruction/anatomic abnormalities, underlying disease (like diabetes)
What are the bacterial virulence factors for UTI causing bacteria?
fimbriae, hemolysins, motility, adhesins, toxins, and polysaccharide coatings
What are the symptoms of a cystitis UTI?
dysuria, pyuria, frequent voiding, strong and persistent urge to urinate, cloudy/bloody/malodorous urine, pelvic pressure, lower abdominal discomfort, and NO fever
What are the symptoms of a pyelonephritic UTI?
symptoms of cystitis as well as fever, chills, flank pain, nausea/vomiting, and hematuria
What is flank pain?
the area where the kidneys are become painful
What are the symptoms of acute prostatitis?
fever/chills, symptoms of cystitis, enlarged and very tender prostate
What are the symptoms of chronic prostatitis?
acute or mild symptoms of pain, dysuria
What are the symptoms of urethritis?
typically seen in STDs (gonorrhea and chlamydia), dysuria, purulent discharge
What pathogen typically causes UTI?
often E.coli (80%)
What other pathogens can cause UTIs?
Staph. saprophyticus - sexually active females
Enteric GNR
pseudomonas, candida, and enterococcus (in hospitals)
What can cause prostatitis?
E. coli, other enteric GNR, and enterococcus
What pathogen is implicated in pediatric UTIs?
E. coli in young females, E. coli and proteus in young males, enterococcus in both
How do we diagnose UTI?
symptoms is a major portion, then we do urinalysis and then a urine culture
How do we collect a specimen for UTI?
urine needs to be collected in the cleanest manner possible to avoid contamination; do midstream, clean catch (most common); straight catheterization, suprapubic aspiration, indwelling catheter; proper cleaning of genital folds prior to specimen
How do we NOT collect a urine sample for culture?
never take it from a catheter bag, it needs to be FRESHLY out of the catheter
How are suprapubic aspirations done?
often used in kids, needle from abdomen into bladder so urine can be taken with a syringe
How do we transport urine speicmen?
use boric acid to preserve the specimen at room temp up to 48 hours, if not get to lab and examined with 30 minutes OR refrigerate up to 24 hours
How do we culture urine?
plant urine on agar plate, sit in incubator for 18-24 hours, identify bacteria that grow, and perform antibiotic susceptibilities
How does urine culture differ from other cultures?
mix sample before culturing; use a sterile, calibrated loop to inoculate Sheep Blood Agar or MacConkey Agar plates; do zig zag pattern with our “bubble wand”
What is considered a UTI positive culture result?
> 100^5 CFU/mL of one bacterial species in symptomatic patient; 10^4-10^5 CFU/mL of two bacterial species in symptomatic patient; and 10^4-10^5 CFU/mL predominant uropathogen + mixed flora in symptomatic patient
What is asymptomatic bacteriuria?
any number of bacteria growing from an appropriately collected urine sample in an asymptomatic patient - no treatment, with expceptions
How do we interpret catheter collections?
if signs and symptoms + positive urine culture = UTI
How can we tell is a specimen was contaminated?
clean catch urine with more than two types of organisms growing
What rapid screening methods do we use to diagnose UTI?
direct microscopy, enzymatic methods using a urinalysis dipstick (leukocyte esterase and nitrate reductase), gram staining smear of centrifuged urine, and automated screening methods
How do we treat UTIs?
antibiotic therapy as without it they can be deadly
What antibiotics do we use the treat cystitis?
nitrofurantoin is preferred, then trimethoprim/sulfamethoxazole (TMP/SMX), cephalexin, cefuroxime, or amoxicillin-clavulanate
What antibiotics do we use the treat pylenephritis?
ceftriaxone, aztreonam, or piperacillin/tazobactam then deescalated to TMP/SMX or B-lactam as appropriate
Case Study 1
18-year-old female is seen in clinic due to dysuria and pain in her right costovertebral angle (flank pain) area. Her urinalysis shows 18-25 WBCs per high power field (HPF). She became sexually active 3 months ago.
For Case 1, what is the probable diagnosis?
likely pyelonephritis
For Case 1, what part of the history is notable?
her flank pain, the white cells in her urine, and her recent sexual activity
Case 1 lab results
> 100,000 CFU/mL E. coli
Are the Case 1 lab results significant?
yes because it is significant and the patient has symptoms
Does the patient have a UTI?
yes, she has a UTI due to E. coli
Case Study 2
A 48-year-old female is in neurosurgical ICU following removal of a glioma from the left frontal lobe. She has an indwelling catheter and is being treated with a second-generation cephalosporin for pneumonia. On the 7th postoperative day she spiked a temperature to 104.6 F. Urine and blood cultures were collected.
For Case 2, what is the probable diagnosis?
patient does not have signs or symptoms of UTI - so likely a catheter associated asymptomatic bacteriuria
