<p>Influenza is a significant cause of childhood morbidity and death; it contributes to up to 16% of hospitalizations for respiratory illnesses worldwide. Novel rapid viral diagnostic tests, including molecular diagnostic tests, have the potential to significantly affect both time to diagnosis and selection of optimal anti-infective therapy. However, little is known about current treatment algorithms used in US hospitals. In this study, for hospitalized children in the United States, we aimed to define the current approaches to influenza diagnosis and treatment and to explore reasons for their potential variation. In this study, we aimed to define the current approaches to pediatric influenza diagnosis and treatment in US hospitals, and to explore reasons for their potential variation. Our results suggest a rise in the availability and use of rapid molecular diagnostic testing in addition to continued variability in anti-infective management, particularly with regard to antiviral use.</p>

<p><strong>BACKGROUND: </strong>A rapid increase in multidrug-resistant Gram-negative infections has led to a reemergence of colistin use globally. Although it is well described among adults, colistin use and its associated toxicities in children are poorly understood. We report findings from the largest case series of pediatric colistin use to date.</p>

<p><strong>METHODS: </strong>We queried pediatric infectious diseases specialists from the Emerging Infections Network to identify members who had prescribed intravenous colistin within the past 7 years. We collected relevant demographic and clinical data. Bivariate analyses and multivariable logistic regression were performed.</p>

<p><strong>RESULTS: </strong>Two hundred twenty-nine pediatric infectious diseases specialists completed the survey (84% response); 22% had prescribed colistin to children. Among respondents, 92 cases of colistin use from 25 institutions were submitted. The most commonly targeted organisms were multidrug-resistant Pseudomonas (67.4%), multidrug-resistant Acinetobacter -baumanii (11.9%), carbapenemase-producing Enterobacteriaceae (13.0%) and extended-spectrum β-lactamase producing Enterobacteriaceae (5.4%). Development of resistance to colistin was observed in 20.5% of patients. Additional antimicrobial therapy was administered to 84% of patients, and 22% of children experienced nephrotoxicity (not associated with dosage or interval of colistin prescribed). Renal function returned to baseline in all patients. Children aged ≥13 years had approximately 7 times the odds of developing nephrotoxicity than younger children, even after controlling for receipt of additional nephrotoxic agents (odds ratio 7.16; 95% confidence interval: 1.51-14.06; P = 0.013). Four children exhibited reversible neurotoxicity.</p>

<p><strong>CONCLUSIONS: </strong>Most pediatric infectious diseases specialists have no experience prescribing colistin. Colistin use in children has been associated primarily with nephrotoxicity and, to a lesser extent, neurotoxicity, both of which are reversible. Emergence of resistance to colistin is concerning.</p>