Bacteremia due to Achromobacter xylosoxidans in neonates: clinical features and outcome

OBJECTIVE: We report an outbreak of Achromobacter xylosoxidans at a neonatal intensive care unit. We aimed to present clinical, laboratory and treatment data of the patients. MATERIALS AND METHODS: All consecutive episodes of bacteremia due to A. xylosoxidans at our neonatal intensive care unit, beginning with the index case detected at November 2009 until cessation of the outbreak in April 2010, were evaluated retrospectively. RESULTS: Thirty-four episodes of bacteremia occurred in 22 neonates during a 6-month period. Among the affected, 90% were preterm newborns with gestational age of 32 weeks or less and 60% had birth weight of 1000 g or less. Endotracheal intubation, intravenous catheter use, total parenteral nutrition and prolonged antibiotic therapy were the predisposing conditions. Presenting features were abdominal distention, thrombocytopenia and neutropenia. The mortality rate was 13.6% and the majority of isolates were susceptible to piperacillin-tazobactam, carbapenems and trimethoprim-sulfametoxazole, and resistant to gentamycin. More than half were breakthrough infections. Despite intensive efforts to control the outbreak by standard methods of hand hygiene, patient screening and isolation, containment could be achieved only after the neonatal intensive care unit was relocated. The investigation was not able to single out the source of the outbreak. CONCLUSION: A. xylosoxidans has the potential to cause serious infections in premature babies. More studies are needed to determine the importance of different sources of infection in hospital units.