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Acute pyelonephritis in pregnancy with recent ESBL-producing Escherichia coli isolate — MSRA MCQ

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HardInfectious DiseasesAcute pyelonephritis in pregnancy with recent ESBL-producing Escherichia coli isolateMSRA

A 29-year-old woman who is 23+4 weeks pregnant presents with 18 hours of fever, rigors, dysuria and left loin pain. She has nausea but is drinking and retaining oral medication. Her temperature is 38.5°C, pulse 102 beats/minute, BP 112/68 mmHg, respiratory rate 18 breaths/minute and oxygen saturation 99% on air. She has left costovertebral-angle tenderness. Her eGFR is 96 mL/min/1.73 m² and she has no drug allergies. Six weeks ago, a urine culture obtained during symptomatic cystitis grew ESBL-producing Escherichia coli resistant to cefalexin and co-amoxiclav but susceptible to nitrofurantoin and fosfomycin. She has not received antibiotics since. What is the most appropriate management today?

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Correct answer: E — Obtain a midstream urine sample, seek same-day microbiology and obstetric advice, and arrange hospital assessment for empiric treatment guided by prior susceptibility

Explanation lettering: B = shown as A · C = shown as B · A = shown as C

This is acute pyelonephritis, not lower UTI: fever, rigors and costovertebral-angle tenderness indicate upper-tract infection. A urine sample should be sent before antibiotics. Although she is haemodynamically stable and can take oral medication, pregnancy warrants consideration of referral or specialist advice because pyelonephritis carries risks including sepsis and preterm labour. The previous ESBL-producing isolate is directly relevant to empiric treatment. Cefalexin is normally NICE first-choice oral treatment in pregnancy, but the recent isolate was resistant, so option C is unsuitable. Co-amoxiclav is also resistant on the prior culture and is not a routine oral choice for pyelonephritis in pregnancy (D). Nitrofurantoin and oral fosfomycin may attract because the previous isolate was susceptible and both are used for lower UTI; however, neither achieves adequate renal-tissue concentrations for pyelonephritis (A and B). She does not currently require emergency sepsis management or automatic intravenous treatment solely because of pregnancy, but her pregnancy plus likely resistant organism means same-day specialist input and hospital assessment are the safest route to prompt, appropriately targeted empiric therapy while current culture results are pending.

Reference: NICE NG111: Pyelonephritis (acute): antimicrobial prescribing — Recommendations (31 October 2018) — https://www.nice.org.uk/guidance/NG111/chapter/recommendations NICE NG111: Pyelonephritis (acute): antimicrobial prescribing — Summary of the evidence (31 October 2018) — https://www.nice.org.uk/guidance/ng111/chapter/summary-of-the-evidence