There is an emerging feeling that we need to start spreading the focus of infection prevention and control beyond acute hospitals. There has always been a sense that standards of infection control outside of acute settings are, shall we say, “different” to acute hospitals (aka non-existent) so it’s great to see a study of an infection control intervention in nursing homes.
The study was a cluster randomised controlled trial of MRSA screening, decolonisation and enhanced environmental disinfection vs. standard precautions in 104 of 157 nursing homes in a Swiss region. The authors chose a rather unusual, pragmatic endpoint of the prevalence of MRSA colonisation after 12 months.
Although there was a significant reduction in MRSA prevalence in both intervention (from 8.9% to 5.8%) and non-intervention (8.9% to 6.6%) nursing homes, the attributable impact of the intervention was non-significant. The most likely reason for this is that standard precautions were re-launched in the non-intervention nursing homes with training and educational materials.
However, another possible explanation for the “failure” of the intervention is the outcome chosen, (prevalence in MRSA carriage among residents at the end of the 12-month study period). It seems to me that this would be influenced more by importation of MRSA from acute hospitals than by in-nursing home transmission. A better measure would have been MRSA acquisition during their stay (negative on admission and subsequent positive specimen), although I appreciate that regular MRSA screening in addition to the admission screening would have been a great challenge.
Another possible explanation for the “failure” of the intervention was that patients with a length of stay less than 3 weeks were excluded, as were those with a life expectancy of less than 1 week. This would result in a substantial pool of patients in the intervention arm who missed out on the intervention. Also, patients were only included in the intervention if they (or their legal representatives) gave oral informed consent. Of those eligible to be enrolled, 13% declined to participate, adding to the pool of patients in the intervention arm who missed out on the intervention.
Another limitation is the environmental disinfection aspect of the intervention. The only detail provided is daily disinfection of several items with 70% alcohol. With all the range of excellent disinfectants available, I have no idea why the authors chose to use 70% alcohol! I suspect that this would have resulted in less of an impact that the cleaning performed in the non-intervention arm! But the cleaning regime in the non-intervention isn’t specified so it’s difficult to be sure.
However, the bottom line seems to be that screening and decolonisation for MRSA has no additional benefit over standard precautions implemented well in this patient cohort.
Image: Ulrlch Joho.