Reviewed by: S. Schaeffer Spires, MD, Duke University School of Medicine

Preventing Staphylococcus aureus transmission in neonatal intensive care units (NICU) poses a unique infection prevention problem given the high complexity, prolonged stays, and the unique involvement of families. In this study, Milstone and colleagues1 describe an initiative of decolonizing parents to prevent neonatal acquisition of S. aureus. Previous studies have shown significant decreases in S. aureus clinical cultures and infections after routine surveillance and decolonization of infants colonized with S. aureus. However, the same authors from this current study have observed that 39% of decolonized infants became recolonized with genetically similar strains.2 Thus, they set out to study a novel intervention of decolonizing parents.  

The study design was a multicenter, double-blind, randomized clinical trial at two tertiary NICUs in Baltimore, Maryland evaluating the role of parents as primary reservoirs for S. aureus in neonates in the NICU. The primary outcome was neonatal acquisition of a S. aureus strain concordant with the parents’ strain within 90 days of randomization. They screened 3215 parental units (2 biological parents or 1 parent plus another primary caregiver), but only 236 were positive for S. aureus at screening. 117 parental units were randomized to intervention (nasal mupirocin and daily CHG wipes for 5 days) and 119 to placebo (nasal petrolatum ointment and non-CHG wipes). They confirmed that parents are a primary reservoir for S. aureus; 56.8% (42) of the 74 infants that acquired S. aureus had concordant strains with the parents within 90 days of randomization, 14.6% (13/89) in the intervention group compared to 28.7% (29/101) in the placebo group. Treating parents reduced the hazard of acquiring concordant S. aureus colonization by NICU discharge (16.9% vs 28.7%, HR 0.50 [95% bias-corrected and accelerated CI, 0.20 to 0.92]). The neonates in the intervention group also had a lower rate of acquiring any S. aureus strain (36.0% vs 45.5%, HR 0.62[95% bias-corrected and accelerated CI, 0.34 to 0.95]). Limitations to the generalizability of this study’s finding include the fact that these NICUs were already actively identifying and decolonizing neonates. Second, the need to screen over 3000 parents to be able to include just over 200 parental units makes it difficult to increase the power of a study enough to evaluate the impact of this measure on the rarer outcome of S. aureus infections. Thirdly, this intervention may cause more stress to NICU parents who are already in a highly stressful situation and may have other unintended consequence, such as less visitation or parental involvement.  However, the authors allude to the fact that more information is to come that may shed some light on this very issue.

While we know that identifying and treating S. aureus carriers can decrease colonization and reduce infection, there is still inadequate safety data in neonates for the use of antibiotics and skin antisepsis for decolonization. Thus, the of the appeal of this intervention is that it offers an option to protect the vulnerable with less chance of harm.  

References:

  1. Milstone AM, Voskertchian A, Koontz DW, et al. Effect of Treating Parents Colonized With Staphylococcus aureus on Transmission to Neonates in the Intensive Care Unit: A Randomized Clinical Trial. JAMA. December 2019. DOI: 10.1001/jama.2019.20785
  2. Akinboyo IC, Voskertchian A, Gorfu G, et al. Epidemiology and risk factors for recurrent Staphylococcus aureus colonization following active surveillance and decolonization in the NICU. Infect Control Hosp Epidemiol. 2018;39(11):1334-1339. doi: 10.1017/ice.2018.223