Quiz: Urinary Tract Infections — 27 questions

1. What is the epidemiological position of urinary tract infections among community-acquired infections?

A. They are the second most frequent site

B. They are the third most frequent site

C. They are an uncommon community-acquired site

D. They are the most frequent site

Answer: (A)

Explanation

Urinary tract infections rank second among the sites of community-acquired infections. They are therefore less frequent than the leading site but more frequent than sites ranked third or lower.

2. Which pattern best describes the frequency of urinary tract infections by sex and age?

A. They are more frequent in men, while in women they occur mainly after age 50

B. They occur mainly in women after age 50 and in men during adolescence

C. They have similar frequencies in both sexes, with a peak during childhood

D. They are more frequent in women, while in men they occur mainly after age 50

Answer: (D)

Explanation

Urinary tract infections are more common in women, with peaks at the beginning of sexual activity and after menopause; in men, they occur mainly after age 50. The male pattern is associated with benign prostatic hyperplasia rather than the female age pattern.

3. Which organism causes the largest proportion of urinary tract infections?

A. Staphylococcus saprophyticus, causing about 60–80% of cases

B. Escherichia coli, causing about 60–80% of cases

C. Enterococci, causing about 5–10% of cases

D. Proteus, causing about 5–10% of cases

Answer: (B)

Explanation

Escherichia coli is the main causative organism and accounts for approximately 60–80% of urinary tract infections. Staphylococcus saprophyticus and Proteus each account for about 5–10%, while enterococci are less common.

4. Which part of the urinary tract is normally colonized by digestive flora?

A. The renal pelvis

B. The ureters

C. The urinary bladder

D. The distal urethra

Answer: (D)

Explanation

The urinary tract is normally sterile except for the distal urethra, which is colonized by digestive flora. The bladder, ureters, and renal pelvis are not normally colonized.

5. A urinary infection begins in the bladder and later reaches a kidney. Which route of spread does this pattern represent?

A. A hematogenous route through the bloodstream

B. A descending route from the renal circulation

C. An ascending route from the lower urinary tract

D. A lymphatic route from the pelvic tissues

Answer: (C)

Explanation

Most urinary infections spread by an ascending route, beginning in the lower urinary tract and potentially reaching the kidneys or prostate. Hematogenous infection reaches the urinary tract through the bloodstream and is less common.

6. Which combination represents natural urinary defenses against infection?

A. Persistent bladder filling, interrupted ureteral flow, and diluted urine

B. Frequent urination, acidic urine, and antibacterial urinary proteins

C. Reduced urine flow, alkaline urine, and prolonged bladder retention

D. Short urethral length, infrequent voiding, and reduced bladder emptying

Answer: (B)

Explanation

Natural defenses include frequent urination, acidic urine, antibacterial urinary proteins, and effective urinary flow and bladder emptying. The other combinations describe conditions that can impair defense or do not reflect normal protective mechanisms.

7. Which condition is recognized as a risk factor for urinary tract infection?

A. Regular bladder emptying

B. Antibacterial prostatic secretions

C. Continuous ureteral urine flow

D. Use of spermicides or diaphragms

Answer: (D)

Explanation

Spermicides and diaphragms can alter the vaginal environment and increase the risk of urinary tract infection. The other choices describe urinary defenses rather than infection-promoting factors.

8. Which patient characteristic increases the risk of complications from a urinary tract infection?

A. A creatinine clearance below 30 mL/min

B. A creatinine clearance above 90 mL/min

C. A recent uncomplicated episode in a healthy adult

D. A normal urinary tract without relevant comorbidity

Answer: (A)

Explanation

Creatinine clearance below 30 mL/min is a risk factor for complications, along with conditions such as pregnancy, male sex, urinary abnormalities, frailty, and severe immunosuppression. A severity criterion, in contrast, indicates an immediately dangerous clinical state rather than merely increased management complexity.

9. Which finding is classified as a severity criterion in urinary tract infection?

A. A Quick SOFA score above 2

B. A history of benign prostatic hyperplasia

C. A short urethra–anus distance

D. A simple urinary catheterization

Answer: (A)

Explanation

A Quick SOFA score above 2 is a severity criterion, as are septic shock and a urological procedure other than simple catheterization. Simple catheterization and the other listed conditions are not classified as severity criteria in this framework.

10. Which presentation best fits simple acute cystitis in a woman?

A. Urinary symptoms without fever or flank pain

B. Pelvic pain with fever and prostate tenderness

C. Fever and unilateral flank pain with chills

D. Urinary symptoms with pregnancy and urinary obstruction

Answer: (A)

Explanation

Simple acute cystitis is a lower urinary tract infection characterized by urinary symptoms without fever or flank pain. Fever and flank pain instead suggest an upper urinary infection such as pyelonephritis.

11. Which patient has cystitis with complication risk rather than simple acute cystitis?

A. A man with urinary symptoms and a comorbidity

B. A healthy 30-year-old woman with dysuria

C. A healthy woman over 65 without other illness

D. A woman with frequency but no systemic symptoms

Answer: (A)

Explanation

Male sex and comorbidity are factors associated with cystitis with complication risk. Simple cystitis can include an older woman when she is in good general health and has no comorbidity.

12. A patient has had four episodes of cystitis during the past year; how should this pattern be classified?

A. Complicated pyelonephritis

B. Simple acute cystitis

C. Recurrent cystitis

D. Persistent prostatitis

Answer: (C)

Explanation

Recurrent cystitis is defined as at least four episodes within 12 months. Risk factors include sexual intercourse, low fluid intake, infrequent urination, constipation, prolapse, and post-void bladder residue.

13. Which symptom cluster most strongly suggests acute pyelonephritis?

A. Dysuria with urinary incontinence and pelvic discomfort

B. Abrupt unilateral flank pain, fever, chills, and lumbar tenderness

C. Acute retention with testicular pain but no fever

D. Frequent small-volume urination with cloudy urine

Answer: (B)

Explanation

Pyelonephritis typically begins abruptly with unilateral flank pain, fever, chills, and pain on lumbar percussion. Lower urinary symptoms without systemic features are more consistent with cystitis.

14. What does a urine dipstick detect that helps assess a urinary infection?

A. Calcium and bilirubin

B. Hemoglobin and ketones

C. Protein and glucose

D. Leukocytes and nitrites

Answer: (D)

Explanation

The urine dipstick is a first-line test that detects leukocytes, reflecting inflammation, and nitrites produced by Enterobacteriaceae. Leukocytes may occur with various urinary infections, whereas nitrites depend on nitrite-producing bacteria.

15. How should a negative urine dipstick result be interpreted in a patient without a urinary catheter?

A. It confirms infection with Enterobacteriaceae

B. It can help exclude urinary infection

C. It proves that antibiotic treatment has failed

D. It indicates a highly specific positive test

Answer: (B)

Explanation

The dipstick has good negative predictive value in patients without catheters, so a negative result can help exclude infection. Its positive result is less specific because leukocytes may accompany different urinary infections.

16. Which procedure is appropriate for collecting a urine culture?

A. Collect the first urine immediately without cleansing

B. Collect urine after antibiotics in a nonsterile container

C. Collect a random sample after several repeated voids

D. Discard the first 20 mL and collect the next 20–30 mL after cleansing

Answer: (D)

Explanation

Urine culture should be collected before antibiotics after hand washing and perineal or urethral cleansing, preferably after four hours without urination. The first 20 mL is discarded, and the following 20–30 mL is collected in a sterile container.

17. Which laboratory finding supports a diagnosis of urinary infection?

A. Leukocyturia below $10/mm^3$ with no measurable bacteriuria

B. Leukocyturia above $10/mm^3$ with bacteriuria above $10^4$ colony-forming units per milliliter

C. Leukocyturia at $10/mm^3$ with bacteriuria below $10^3$ colony-forming units per milliliter

D. Bacteriuria below $10^2$ colony-forming units per milliliter with normal leukocytes

Answer: (B)

Explanation

Urinary infection is supported by leukocyturia greater than $10/mm^3$ or $10^4/ml$ together with bacteriuria greater than $10^4$ colony-forming units per milliliter, with interpretation depending on sex and organism. Lower values do not meet the stated supportive thresholds.

18. What is the recommended first-line treatment for simple acute cystitis?

A. Nitrofurantoin after waiting for the antibiogram

B. Dual therapy with a cephalosporin and aminoglycoside

C. Single-dose fosfomycin-trometamol

D. A parenteral fluoroquinolone for several days

Answer: (C)

Explanation

Simple acute cystitis is treated empirically with single-dose fosfomycin-trometamol as first-line therapy, with pivmecillinam as a second-line option. A urine culture is generally reserved for treatment failure in this setting.

19. If treatment cannot await the antibiogram in cystitis with complication risk, which regimen is recommended?

A. Aminoglycoside first-line and cephalosporin second-line

B. Nitrofurantoin first-line and fosfomycin-trometamol second-line

C. Fluoroquinolone first-line and macrolide second-line

D. Single-dose fosfomycin-trometamol first-line and pivmecillinam second-line

Answer: (B)

Explanation

When treatment must begin before the antibiogram is available, nitrofurantoin is the first-line choice and fosfomycin-trometamol is the second-line choice for cystitis with complication risk. When feasible, therapy should instead await susceptibility results.

20. Which treatment is appropriate for simple acute pyelonephritis?

A. Topical therapy combined with increased fluid intake

B. A parenteral third-generation cephalosporin or a fluoroquinolone

C. Single-dose oral fosfomycin-trometamol

D. Pivmecillinam without an agent for renal tissue infection

Answer: (B)

Explanation

Simple acute pyelonephritis requires treatment suitable for parenchymal infection, such as a parenteral third-generation cephalosporin or a fluoroquinolone. Single-dose fosfomycin is a regimen for simple cystitis, not pyelonephritis.

21. How should severe pyelonephritis generally be managed?

A. With hospital treatment and dual therapy including an aminoglycoside

B. With oral pivmecillinam while awaiting symptom improvement

C. With outpatient single-dose fosfomycin-trometamol

D. With supportive care and no antibacterial combination

Answer: (A)

Explanation

Severe pyelonephritis requires hospital treatment and dual antibiotic therapy combining a third-generation cephalosporin or fluoroquinolone with an aminoglycoside. Less intensive cystitis regimens do not provide the required approach for severe upper urinary infection.

22. Which finding best defines asymptomatic bacteriuria?

A. Bacteria are present in urine without urinary symptoms

B. Urinary symptoms occur without detectable bacteria

C. Fever accompanies bacteria found in the bloodstream

D. Pyuria occurs together with severe flank pain

Answer: (A)

Explanation

Asymptomatic bacteriuria means that bacteria are detected in urine while the patient has no related symptoms. A symptomatic urinary infection requires microbiological findings together with clinical signs.

23. In which situation is antibiotic treatment of asymptomatic bacteriuria recommended?

A. In an institutionalized older adult

B. During pregnancy

C. In a frail patient without urinary symptoms

D. In a catheterized patient without clinical signs

Answer: (B)

Explanation

Antibiotic treatment is recommended for asymptomatic bacteriuria in pregnant women. Institutional living, frailty, or catheterization without symptoms does not by itself justify treatment.

24. Which factor is most strongly associated with nosocomial urinary tract infections?

A. Routine blood pressure monitoring

B. Bladder catheterization

C. Short-term dietary restriction

D. Limited exposure to hospital equipment

Answer: (B)

Explanation

Nosocomial urinary tract infections represent about 40% of nosocomial infections and are mainly associated with bladder catheterization. The other factors do not represent the principal documented risk association.

25. What proportion of urinary catheters are expected to be colonized by bacteria approximately 30 days after insertion?

A. About 25%

B. About 50%

C. About 75%

D. About 100%

Answer: (D)

Explanation

Bacterial colonization reaches approximately 100% by day 30, compared with about 30% by day 3. The lower percentages describe earlier or inaccurate estimates rather than the documented 30-day finding.

26. Which strategy best reduces the risk of catheter-associated infection?

A. Review the indication daily and remove the catheter promptly

B. Prefer continuous drainage when intermittent catheterization is feasible

C. Maintain an indwelling catheter after the indication has resolved

D. Replace every catheter on a fixed schedule regardless of need

Answer: (A)

Explanation

Prevention includes limiting indications, reviewing the need daily, removing the catheter promptly, and using intermittent catheterization when feasible. Maintaining an unnecessary catheter or favoring continuous drainage increases exposure to catheter-related risk.

27. A patient with a catheter-associated urinary infection has had the catheter in place for 16 days. What catheter management is appropriate if removal is not feasible?

A. Remove the drainage bag and continue the same catheter

B. Leave the catheter unchanged and select antibiotics by symptoms alone

C. Replace the catheter only after completing the antibiotic course

D. Change the catheter and base antibiotics on infection type and susceptibility

Answer: (D)

Explanation

When a catheter has been in place for at least 14 days, it should be changed if it cannot be removed, and antibiotic selection should reflect the infection type and susceptibility results. Symptoms alone do not provide the microbiological guidance needed for treatment.