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Urinary tract infection and pyelonephritis
Separate simple cystitis (short treatment without culture), pyelonephritis (fever and flank pain — culture and systemic treatment) and asymptomatic bacteriuria — which is treated only in pregnancy and before a urological procedure.
Why it matters in the exam
Questions present a woman with burning, frequency and urgency without fever — simple cystitis, treated without culture with nitrofurantoin for 5 days or a single dose of fosfomycin. A standard distractor is a nursing-home resident or a catheterised patient with a positive culture and no symptoms: do not treat. The exceptions are pregnancy — where asymptomatic bacteriuria is also treated — and before a urological procedure that makes the mucosa bleed.
Pyelonephritis presents with fever, flank pain and costovertebral angle tenderness, sometimes with nausea. Here a urine culture is taken (and blood cultures if the patient is unwell), and treatment is chosen by severity and local resistance: ciprofloxacin for 7 days if local resistance is low, or ceftriaxone followed by oral treatment guided by susceptibility. If there is no improvement within 48–72 hours, or there is sepsis, imaging (ultrasound or CT) is needed to look for obstruction or an abscess — an obstructed, infected kidney needs urgent drainage. In men, a urinary infection is considered complicated and is treated for at least 7 days, and fluoroquinolones are avoided in pregnancy.
Key points
- Simple cystitis: nitrofurantoin for 5 days or fosfomycin 3 g, without culture.
- Asymptomatic bacteriuria: treat only in pregnancy and before a urological procedure.
- Pyelonephritis: culture, ciprofloxacin for 7 days or ceftriaxone.
- No improvement in 48–72 hours → imaging; obstruction with infection → urgent drainage.
- Men: complicated infection, at least 7 days; pregnancy: no fluoroquinolones.
Summary table
| Situation | Definition | Treatment | Exam note |
|---|---|---|---|
| Simple cystitis | Non-pregnant woman, burning and frequency, no fever | Nitrofurantoin 100 mg twice a day for 5 days, or fosfomycin 3 g once | No culture in a typical picture |
| Asymptomatic bacteriuria | Positive culture without symptoms | Treat only in pregnancy and before a urological procedure | Not in older people, diabetics or catheters |
| Pyelonephritis | Fever, flank pain, angle tenderness | Culture; ciprofloxacin 7 days or ceftriaxone | Imaging if no improvement in 48–72 hours |
| Obstruction with infection | Pyelonephritis + hydronephrosis or stone | Urgent drainage (stent or nephrostomy) | A urological emergency |
| Man | Any urinary infection | At least 7 days | Think of prostatitis |
| Pregnancy | Bacteriuria or infection | Beta-lactam, nitrofurantoin (not near term) | No fluoroquinolones |
A free exam question
בת ,40 מאושפזת עקב פיילונפריטיס. בתרבי ו ת השתן ו הדם צמיחה של E. coli , עמיד ל- trimethoprim-sulfamethoxazole ורגיש לכל הת רופות האחרות שנבדקו. איזה מהמשפטים הבאים לגבי יעילות הטיפול האנטיביוטי הוא הנכון ביותר? (the question as examined, in Hebrew)
- א. טיפול תוך ורידי ב- quinolone יעיל יותר מטיפול פומי
- ב. ל טיפול של 14 ימים תוצאות טובות יותר מטיפול של 7 ימים
- ג. טיפול פומי ב- beta lactam יעיל פחות מ ט יפול ב- quinolone
- ד. fosfomycin פומי לשבועיים הוא טיפול מקובל ויעיל במצב זה
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Sources
- IDSA/ESCMID International Clinical Practice Guidelines for the Treatment of Acute Uncomplicated Cystitis and Pyelonephritis in Women, 2010 — First-line agents and durations
- EAU Guidelines on Urological Infections, 2024 — Asymptomatic bacteriuria, complicated UTI and pyelonephritis
- Harrison's Principles of Internal Medicine, 21st edition (2022) — Urinary Tract Infections, Pyelonephritis, and Prostatitis
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-02. The text may contain errors; when in doubt, check the source.