Short versus prolonged courses of antibiotic therapy for children with uncomplicated Gram-negative bacteraemia

The optimal duration of antibiotic therapy for uncomplicated Gram-negative bacteraemia remains undefined. Our objective was to compare clinical outcomes of receiving short (7-10 days) versus prolonged (>10 days) durations of antibiotic therapy for children with uncomplicated Gram-negative bacteraemia.

We conducted a retrospective cohort study of children with uncomplicated Gram-negative bacteraemia at The Johns Hopkins Hospital between 2002 and 2012. We estimated the risk of bacteraemic relapse among children who received short versus prolonged durations of antibiotic therapy using 1:1 nearest neighbour propensity score matching without replacement prior to performing regression analysis.

There were 170 matched pairs that were well balanced on baseline covariates. The median duration of therapy in the short and prolonged courses was 10 days (IQR 10-10) and 14 days (IQR 14-17), respectively. The 30 day mortality was similar between the groups (OR 1.12; 95% CI 0.96-1.21). A prolonged duration of antibiotic therapy did not reduce the relapse risk compared with shorter durations (adjusted hazard ratio 0.67; 95% CI 0.35-1.27). Similarly, each additional day of antibiotic therapy was not protective against relapse risk (adjusted hazard ratio 0.99 per additional day; 95% CI 0.92-1.03). There was a trend towards an increased subsequent risk of candidaemia in children receiving longer treatment durations (hazard ratio 2.44; 95% CI 0.97-6.19).

Antibiotic treatment for more than 10 days for uncomplicated bacteraemia in children does not reduce the risk of microbiological relapse compared with shorter-course therapy, but may be associated with an increased risk of candidaemia. Our findings need to be confirmed in a larger, prospective study.