Nasal Mupirocin tops nasal Iodophor antiseptic in setting of CHG bathing in ICU patients: JAMA

Universal nasal mupirocin with CHG bathing prevents all-cause bloodstream infections and methicillin-resistant Staphylococcus aureus (MRSA) infections in intensive care units (ICUs). Antibiotic resistance to mupirocin has raised questions about the advantages of an antiseptic for ICU decolonization.

In the noninferiority, cluster randomized trial of 801 668 admissions at 137 hospitals, the researchers revealed that exposure to nasal mupirocin significantly reduced S aureus clinical cultures by 18.4% versus iodophor in adult ICUs in the context of daily chlorhexidine bathing.

The study was conducted by Susan S. Huang, University of California Irvine School of Medicine, Irvine, and colleagues to compare the effectiveness of iodophor versus mupirocin for universal ICU nasal decolonization in combination with CHG bathing.

For this purpose, the researchers conducted a two-group noninferiority, pragmatic, cluster-randomized trial in US community hospitals all of which used mupirocin-CHG for universal decolonization in ICUs at baseline. It included adult ICU patients in 137 randomized hospitals during baseline (2015 to 2017) and intervention (2017 to 2019). Among the 801 668 admissions in 233 ICUs, the mean of the participants was 63.4 years, and the mean ICU length of stay was 4.8 days.

Universal decolonization involved switching to iodophor-CHG (intervention) or continuing mupirocin-CHG (baseline).

Proportional hazard models were used to evaluate ICU-attributable S aureus clinical cultures (primary outcome), all-cause bloodstream infections, and MRSA clinical cultures to find out differences from baseline to intervention periods between the strategies. In the same hospital network, a comparison of the results was done with a 2009-2011 trial of mupirocin-CHG versus no decolonization. The prespecified noninferiority margin for the primary outcome was 10%.

The researchers reported the following findings:

• Hazard ratios (HRs) for S aureus clinical isolates in the intervention vs baseline periods were 1.17 for iodophor-CHG (raw rate: 5.0 vs 4.3/1000 ICU-attributable days) and 0.99 for mupirocin-CHG (raw rate: 4.1 vs 4.0/1000 ICU-attributable days) (HR difference in differences significantly lower by 18.4% for mupirocin-CHG).
• For MRSA clinical cultures, HRs were 1.13 for iodophor-CHG (raw rate: 2.3 vs 2.1/1000 ICU-attributable days) and 0.99 for mupirocin-CHG (raw rate: 2.0 vs 2.0/1000 ICU-attributable days) (HR difference in differences significantly lower by 14.1% for mupirocin-CHG).
• For all-pathogen bloodstream infections, HRs were 1.00 (2.7 vs 2.7/1000) for iodophor-CHG and 1.01 (2.6 vs 2.6/1000) for mupirocin-CHG (nonsignificant HR difference in differences, −0.9%).
• Compared with the 2009-2011 trial, the 30-day relative reduction in hazards in the mupirocin-CHG group relative to no decolonization (2009-2011 trial) was as follows: S aureus clinical cultures (current trial: 48.1%; 2009-2011 trial: 58.8%) and bloodstream infection rates (current trial: 70.4%; 2009-2011 trial: 60.1%).

"Nasal iodophor antiseptic failed to meet criteria to be considered noninferior to nasal mupirocin antibiotic for the outcome of S aureus clinical cultures in adult patients admitted to ICU in the context of daily CHG bathing," the researchers wrote. "In addition, the results were consistent with nasal iodophor being inferior to nasal mupirocin."

Reference:

Huang SS, Septimus EJ, Kleinman K, et al. Nasal Iodophor Antiseptic vs Nasal Mupirocin Antibiotic in the Setting of Chlorhexidine Bathing to Prevent Infections in Adult ICUs: A Randomized Clinical Trial. JAMA. 2023;330(14):1337–1347. doi:10.1001/jama.2023.17219