Almond oil implicated in a Staphylococcus capitis outbreak in a neonatal intensive care unit

To develop an effective outbreak-control strategy by identifying the source and modes of transmission of Staphylococcus capitis in a 60-bed neonatal intensive care unit (NICU).

We conducted a study among neonates hospitalized during the outbreak (June 2000 through November 2003). All cases of S. capitis colonization or infection detected by clinical samples during the outbreak were included. The molecular analysis of the isolated was assessed by pulsed-field electrophoresis. We reported the description of the outbreak and the measures taken during this investigation.

Thirty-three patients were colonized or infected by S. capitis. Mean gestational age was 28.5+/-4.4 weeks of gestation, mean birth weight was 1068+/-637.3 g and the mean length of hospital stay was 77.9+/-35.9 days. We observed that positive S. capitis cultures were over-represented in six beds of the NICU. Because S. capitis is known to thrive in lipid media, we cultured samples from the almond oil bottles assigned to these beds. S. capitis strain recovered from one of the almond oil sample was genetically identical to the strain recovered from the cases.

Almond oil is an unusual reservoir infection. Control policy allowed prompt institution of measures that were successful in ending the outbreak.