A meta-analysis has revealed significant levels of resistance to commonly prescribed antibiotics for urinary tract infections (UTI) in children. Resistance rates were highest for ampicillin and lowest for nitrofurantoin.

The researchers set out to determine the prevalence of antibiotic resistant E. coli UTIs in children in a primary care setting and to quantify the relationship between prior exposure to antibiotics and subsequent bacterial resistance.

The authors searched the Embase, Medline, Cochrane and ISI Web of Knowledge databases for relevant articles published between 1955 and October 2015. Of 4,246 articles identified, 58 papers were deemed suitable for analysis. Of these, 53 addressed prevalence of resistance, three the association between resistance and previous antibiotic exposure, and two addressed both.

Countries were categorised as either developed or developing depending on their OECD status.

The prevalence of antibiotic-resistant E.coli isolates in OECD countries is shown in table 1. The pooled data from non-OECD countries was much higher for all antibiotics tested.

The five studies that investigated the relationship between prior antibiotic exposure and resistance identified a greater prevalence of antibiotic resistance with more recent exposure. Bacterial isolates from the urinary tract in children who had previously received antibiotics were more likely to be resistant, and the increased risk could persist for up to six months. Odds ratio (OR) 13.23 (95% CI: 7.84-22.31) for exposure 0-6 months previously.

The authors concluded that antibiotic use in children is an important contributor to bacterial resistance, and that this can persist for up to six months after exposure.

When the prevalence of resistance to an antibiotic is 20% or greater it is recommended that is should no longer be considered a first-line therapy.

Around 80% of antibiotics are prescribed in primary care settings.

These findings emphasise the importance of keeping up to date with local microbiological resistance data and checking a child’s antibiotic exposure over the past six months.

Dr Chris Barclay

Bryce A, Hay AD, Lane IF et al. Global prevalence of antibiotic resistance in paediatric urinary tract infections caused by Escherichia coli and association with routine use of antibiotics in primary care: systematic review and meta-analysis. BMJ 2016; 352:i939