1. Nevada ECHO ASP Clinic Quiz-What do you know about cystitis
Nevada ECHO ASP Clinic Quiz-What do you know about cystitis? April 21, 2016
Charles Krasner, M.D.
University of NV, Reno School of Medicine
Sierra NV Veterans Affairs Med Center

12. Urine cultures for Diagnosis Of UTIs in young woman
9 million doctor visits/year!
Customary urine test is the dip stick and the mid-stream culture of voided urine. Up to 77% of cystitis cases are cultured
Traditionally- >100,000 (10⁵)CFUs was called diagnostic of either UTI (bladder infection present) or asymptomatic bacteruria.
More recently as little as 100 CFUs in a voided sample has been positively correlated with coliform (such as E. coli) bladder infection
The problem with this cut off: Many labs will call 0 to 10,000 CFUs (<10⁴) as a negative culture

13. The way the urine test is done, diluting out the urine 1000 times, there may be no growth on the agar plates despite a bladder infection being present

14. What does the results of the urine culture tell you ?
Voided Midstream Urine Culture and Acute Cystitis in Premenopausal Women thomas M. Hooton, M.D., Pacita L. Roberts, M.S., Marsha E. Cox, B.S., and Ann E. Stapleton, M.D. N Engl J Med 2013; 369: November 14, 2013DOI: /NEJMoa
What does the results of the urine culture tell you ?
202 paired samples of mid stream collected urine cultures and catheterized bladder cultures in young woman who had symptoms of uncomplicated cystitis, no features of pyelonephritis
70% of bladder cultures positive
78% of voided mid-stream cultures positive
As few as 10 CFUs of mid-stream cultures of E. coli or Klebsiella pneumoniae– highly correlated with a true bladder infection ( 93% PPV).
In contrast – 22% of mid- stream cultures grew enterococcus or Group B strep- at even 100,000 (10⁵ CFUs) – there was no correlation with bladder cultures- These bugs were not found in the corresponding bladder culture, but E.coli was still cultured in the bladder (but not in the mid-stream culture) in 62% of these cases !
Take Home Message:
I. a young woman with classic cystitis symptoms can have a documented bladder infection, but her midstream urine culture can still be a false negative test ( too few CFUs to be detected on standard urine cultures)
II. Positive mid-stream cultures for enterococcus and Group B strep are most likely contaminants
III. In uncomplicated cases- obtaining cultures as a guide to therapy can be counter productive: either not treating patients with actual infection, or treating patients for the wrong bacteria.

15. Why treat Acute Cystitis?
**Rarely progresses to severe disease even if untreated:
goal is to ameliorate symptoms
In selecting therapy, efficacy as well as “ecologic collateral damage” (selecting for antibiotic resistant bacteria, C. difficile colitis) should be considered equally- fluoroquinolones should be avoided, except in pyelonephritis
Nitrofurantoin, Septra, fosfomycin are therefore first line agents
New Study- still >50% of Rxs are for Cipro, most of the time for > than 3 days. Septra #2, nitro #3 , fosfomycin-no Rx

16. Question: Which of these options is the quickest, most sensitive and cheapest way to diagnose a UTI?
Ask the patient “do you feel like you have a bladder infection- do you have both a sense of urgency and burnig when you urinate?”
Do a dip stick and treat only if leukocytes or nitrite positive?
Send the urine for culture, wait 2 days, and treat the patient only if >100,000/ml colonies

17. Diagnosis of Uncomplicated Cystitis
Symptoms only: +dysuria, +frequency, no discharge or irritation:***90% chance of cystitis***
Dipstick: leukocyte esterase + and/or nitrite + only 75% sensitive, so symptoms more important even if dip is negative
Culture:10⁵ (100,000) bacterial CFU- traditional criterion of UTI- 50% sensitive -will miss up to half of cases of UTI – counts of 100 to 10,000 colonies – all at levels that may be called as “no growth” by micro lab. Least sensitive diagnostic test
Thomas Hooton,M.D. UTI review NEJM 3/15/2012- don’t do dip stick, u/a or culture- can be negative or misleading – just treat on basis of classic symptoms in uncomplicated UTI

18. Bottom Line
Think twice before ordering a urine culture- go by symptoms and signs. Only culture in possible pyelonephritis, unclear diagnosis, complicated cases or treatment failure
Consider Macrodantin or Septra as first line therapy, quinolones if they are ill
Mid-stream culture results with enterococcus and GBS can be deceiving – rarely cause of UTI. Most likely still E. coli
If the patient is asymptomatic –if it ain’t broke, don’t fix it!

19. How about treating asymptomatic bacteruria to prevent UTI
How about treating asymptomatic bacteruria to prevent UTI? if it ain’t broke, don’t fix it – treatment of ASB just leads to drug resistant bacteria and side effects from the antibiotic
Antibiotic treatment of ASB does not reduce frequency of symptomatic UTI
Treatment of ASB in diabetes does not reduce adverse outcomes, improve glucose control, or reduce symptomatic UTIs
It does lead to untreatable drug resistant bacteria, c.diff,etc
Only exceptions are pregnancy where asymptomatic bacteriuria is associated with pyelonephritis, growth retardation, neonatal death… and patients undergoing urologic procedures (such as prostate bx)

20. Choosing Wisely® – Advice for Seniors- an initiative of the ABIM and American Geriatrics Society
Many older patients get screening u/a’s and reflex cultures even when they don’t have urgency and burning symptoms. They are then treated for a “UTI”. This is a too common mistake…
“older patients should not be tested or treated for UTI unless they have symptoms”
If you are treated for a true UTI: no follow-up test of cure should be performed
Antibiotics:
have side-effects
can cause future problems like yeast infection and colitis
lead to drug resistant bacteria
are a waste of money