Lecture 36: Dysuria: Urinary Tract Infection

Question 1

An 18-year-old European woman presents to the student health clinic with burning discomfort when she passes urine. She has recently started university and has a new boyfriend. They have been having sex without using condoms

How would you go about diagnosing this?

Answer 1

• You would ask further questions include bladder dysfunction and contraception:
• This isn’t pyelonephritis (kidney) because there’s no systemic symptoms (+ no back pain)
• Could be urethritis, chylamydia and gonorrhea or cystitis?
• Increased frequency of urination is non-specific symptom suggesting either cystitis (inflamed bladder) or urethritis (chlamydia and gonorrhea).
• Urgency of urination is the feeling that person needs to urinate urgently.
  
  • If this is present, it is likely to be cystitis;
  • If this is absent, it is likely to be urethritis.

This patient is likely to have cytstitis.

Question 2

Describe “Urgency of urination”

Answer 2

• Urgency of urination is the feeling that person needs to urinate urgently.
  
  • If this is present, it is likely to be cystitis;
  • If this is absent, it is likely to be urethritis.
    *

Question 3

Define Hesitancy

Answer 3

Hesitancy is when patient needs to urinate, but nothing/few dribbles comes out, or urine flow stops and starts

Question 4

Describe Cramping pain of the bladder

Answer 4

Cramping pain (strangury) of bladder refers to cramping discomfort when urinating.

Question 5

What is the word for inflammation in the…

1) Kidneys
2) Ureter
3) Bladder

Answer 5

1) Pyelonephritis
2) Urethritis
3) Cystitis

Question 6

An 18-year-old European MAN presents to the student health clinic with burning discomfort when HE passes urine. She has recently started university and has a new boyfriend. They have been having sex without using condoms

What is the most likely diagnosis?

Answer 6

Not pyelonephritis (no systemic symptoms)

Less likely that boys/young men get cystitis (compared to females) (move out to in)

Chlamydia in males often cause urethritis, gonorrhoea in males mostly causes urethritis.

Urethritis is likely to be the the cause.

Question 7

An 18-year-old European MAN presents to the student health clinic with burning discomfort when HE passes urine. She has recently started university and has a new boyfriend. They have been having sex without using condoms

What is the most useful thing to do?

Answer 7

• e should be used but not a priority
• d is incorrect as you would do more investigations before prescribing antibiotics. Also augmentin is not the correct treatment for gonorrhea or chlamydia or cystitis
• c correct but B is more correct
• b
• a urine specimens are often contaminated. So often first part of the urine (contaminated) is poured out and you only get the midstream urine
• B is correct because we need to ask Jack his Urinary frequency, urgency of urination, hesitancy and cramping
  
  • This will allow us to determine if the infection is a bladder or a urethral infection.

Question 8

How can you tell if someone has Cystitis or Urethritis?

Answer 8

I_ncreased frequency of urination is non-specific symptom_ suggesting either cystitis (inflamed bladder) or urethritis (chlamydia and gonorrhea).

Urgency of urination is the feeling that person needs to urinate urgently.

• If this is present, it is likely to be cystitis;
• If this is absent, it is likely to be urethritis.

Question 9

An 18-year-old European woman presents to the student health clinic with burning discomfort when she passes urine. She has recently started university and has a new boyfriend. They have been having sex without using condoms

She has bladder cramping and urinary frequency

What is this likely to be? What is the most useful thing to do?

Answer 9

Very likely to be cystitis.

C = NO

D = NO (prescribe augmentin)

E = NO (consel and prescribe condoms)

A = Takes too long.

B = Correct. Can be performed on the spot. Cheap.

Question 10

An 18-year-old European woman presents to the student health clinic with burning discomfort when she passes urine. She has recently started university and has a new boyfriend. They have been having sex without using condoms

A urinary dipstick has shown a high number of white blood cells

What is the most useful thing to do?

Answer 10

Answer = B. Treat her with trimethoprim 300mg nocte for 3nights

You don’t want to delay the treatment- as it is uncomfortale for the patient.

Question 11

What is the word for “white blood cells in urine”

Answer 11

Pyuria

Question 12

How do you diagnose cystitis?

Answer 12

Diagnostic Test

Urine dipstick (immediate result) checks leucocyte esterase produced by WBCs.

• Dipstick sensitivity is >8x10⁶ WBCs/L urine. Symptomatic UTI threshold is >10x10⁶ WBCs/L urine. Therefore, dipstick is able to detect all symptomatic UTI. This enables us to diagnose patient with cystitis and treat immediately.

Midstream urine (delayed result) is more costly ($35), which uses microscopy, culture, susceptibility.

• Only test midstream urine sample if patient does not get better after treatment
• Advantages include bacteria culture, determine antimicrobial sensitivities for suitable treatment

Question 13

Cystitis is confirmed when the Dipstick shows…

Answer 13

• Cystitis is confirmed when patient presents with
  
  • (1) cardinal symptoms of bladder illness/inflammation/dysfunction,
    
    • _Cardinal = ​_primary or major clinical sign or symptom
  • (2) pyuria (white blood cells in urine) via dipstick.

Question 14

What bacteria cause cystitis?

Answer 14

Escherichia coli is a very common cause (>80%).

Staphylococcus saprophyticus (10%) is quite common in young females, less common in older men and post-menopausal women.

Question 15

How do you treat Cystitis?

Answer 15

Guidelines to Cystitis Treatments

The guidelines for the treatment of cystitis suggest use of trimethoprim or nitrofurantoin.

• Trimethoprim 300mg nocte (night per day) for 3 days;
  
  • Used more by GPs becuase you only need to take it once a day
• Or nitrofuratoin 50mg QID (4 times per day) for 3 days
  
  • Used more in hospos because it’s more effective

Treatment should be with antibiotics (safe, effective, convenient, inexpensive due to commonness).

• There are two folate antagonists used commonly in NZ, which are trimethoprim and co-trimoxazole (made up of 400mg sulfamethoxazole (sulfonamides) and 80mg trimethoprim).
• These agents are bacteriostatic with broad spectrum of activity. They are very good against streptococci and staphylococci, Escherichia coli and other enterobacteriaceae, also others such as Pneumocystis jirovecii.

Question 16

A 58 year old woman has hypertension and a urine was sent to the lab to look for proteinuria, casts, etc. It was also cultured and a pure growth of E. coli was found.

What Is The Best Course Of Action?

Answer 16

Asymptomatic bacteriuria is occurrence of bacteria in urine without causing symptoms. The condition may not need treatment. This makes it different from a urinary tract infection that is caused by bacteria.

• Asymptomatic bacteriuria occurs in a small number of healthy people. It affects women more often than men. The reasons for lack of symptoms are not well understood.
• Most people who have this condition do not need treatment because bacteria are not causing any harm. People who have urinary catheters often will have bacteriuria, but most will not have symptoms.

Question 17

What are the 3 bacterial resistance factors to folate antagonist treatments?

Answer 17

All these drugs are folate antagonists, which inhibit bacterium’s ability to synthesise purines and thymidine, so they cannot undergo DNA synthesis (inhibit replication).

1. Alter enzyme target (antibiotic unable to bind) (DHPS sul1 and sul2; DHFR dfrA)
2. Make more enzyme (most common, overwhelm antibiotics activity) (DHPS felP and DHFR folA)
3. Scavenge thymidine (no longer use folate pathway, but obtain from external environment)

Question 18

What are the common causes of Cystitis? (Bacteria)

Answer 18

Bacteria That Cause Cystitis

• Escherichia coli is a very common cause (>80%).
• Staphylococcus saprophyticus (10%) is quite common in young females, less common in older men and post-menopausal women.

Question 19

How do you diagnose Cystitis?

Answer 19

1. Typical symptoms? Dipstick shows pyuria?

• Cystitis is confirmed when patient presents with (1) cardinal symptoms of bladder illness/inflammation/dysfunction, and also (2) pyuria (white blood cells in urine) via dipstick.
• If patient have pyuria in absence of cardinal symptoms, investigate for both cystitis and urethritis (chlamydia, gonorrhoea).
  
  • If chlamydia is suspected, then give single dose of azithromycin, but investigations should still be carried out to diagnose.

2. Possible treatment?

• ~15-20% patients will not respond completely to treatment. As a result, person will have symptoms for a few extra days.
• Cystitis is an otherwise benign illness last for 6-8 weeks without antibiotics. 95% adults with cystitis can continue to work.

2. Further problems? Reassess? Send midstream urine to lab?

• Microscopic visualization of bacteria correlates with culture
• Contamination is important issue
  
  • Contamination is more common in females than males, due to urethra length
  • Paediatric urine collection bags have highly contaminated sample, since it is in contact with nappy, infant’s skin and perineum. Instead, urine sample is collected from infants by inserting a needle above symphysis pubis into bladder

Question 20

How do you treat cystitis?

Answer 20

Treatment should be with antibiotics (safe, effective, convenient, inexpensive due to commonness).

• There are two folate antagonists used commonly in NZ, which are trimethoprim and co-trimoxazole (made up of 400mg sulfamethoxazole (sulfonamides) and 80mg trimethoprim).
• These agents are bacteriostatic with broad spectrum of activity. They are very good against streptococci and staphylococci, Escherichia coli and other enterobacteriaceae, also others such as Pneumocystis jirovecii.

Guidelines to Cystitis Treatments

The guidelines for the treatment of cystitis suggest use of trimethoprim or nitrofurantoin.

• Trimethoprim 300mg nocte (night per day) for 3 days;
• Or nitrofuratoin 50mg QID (4 times per day) for 3 days

Question 21

How do you treat pyelonephritis?

Answer 21

Because of rapid spread of bacteria around body, we need bactericidal antibiotic (killing) that permeates tissue around body, rather than bacteriostatic (stop dividing) antibiotic.

Antibiotic treatment is often intravenous at first, then rapid change to oral treatment when responds.

• Gentamicin 5mg/kg (lean BW) daily intravenous (pyelonephritis is almost always caused by enteric gram-negative bacteria)
• Cefuroxime or augmentin (amoxicillin-clavulanate) as alternatives

Historically, total duration of treatment has been 14 days (includes IV and oral doses), but shorter courses (7-10 days) are increasingly used for uncomplicated cases. Be watchful for signs or symptoms of septic shock!

Question 22

Note that patient with _____won’t normally develop ______, but patient that presents with _____might have _____.

Answer 22

Note that patient with cystitis won’t normally develop pyelonephritis, but patient that presents with pyelonephritis might have cystitis.