Methicillin-resistant Staphylococcus aureus omphalitis in neonates: An emerging threat?

The incidence and severity of neonatal omphalitis has decreased after wide use of antiseptic delivery techniques. However, methicillin-resistant Staphylococcus aureus (MRSA) infectious disease is increasing in neonates. The significance of MRSA omphalitis has never been addressed in the literature. We retrospectively reviewed medical records of infants with the diagnosis of omphalitis in a single institution from April 1996 through May 2004. The bacteriologic profiles were analyzed. Gestational age, birth weight, mode of delivery, age at onset, clinical symptoms, and laboratory data were also collected for analysis. A total of 46 neonates were enrolled, including eight preterm infants. The incidence of omphalitis was 0.89 per 1000 live births. In full-term infants, 32 (84%) had umbilical cultures positive for bacterial infections. Among the full-term infants the predominant bacteria included Staphylococcus aureus (54%), with half of them being MRSA (29%), followed by Enterobacter cloacae (12%), Escherichia coli (10%), and Klebsiella spp (7%). In the preterm infants, five of the seven umbilical culture results showed MRSA. The MRSA group had longer hospitalization than the non-MRSA group (p=0.02). Initial treatment failure of omphalitis due to MRSA was found in 18% of the total neonatal omphalitis. One full-term infant died due to complications with necrotizing fasciitis and septic shock. Despite the low incidence of neonatal omphalitis, the threat of severe infection remains. Recognition of MRSA omphalitis is warranted due to the predominance of MRSA and its potential for lethal complications.