Impact of hypochlorite disinfection on methicillin-resistant Staphylococcus aureus rate

Mahamat et al previously described a hospital intervention showing declining MRSA rates because of a series of infection control interventions applied between February 2001and January 2005. The decreased MRSA rates were significantly associated with use of alcohol-based hand disinfection, patient admission screening, environmental screening and environmental disinfection. The environmental decontamination regimen included terminal disinfection of the environment in isolation rooms and cohort areas by application of 1:1000 sodium hypochlorite in place of the standard detergent, with emphasis on the disinfection of common hand touch sites. The purpose of this research was to evaluate the impact of stopping this disinfection regimen. The new study showed that stopping the hypochlorite disinfection in February 2005 was associated with an increase in MRSA rates from 10% to 25% (P= 0.03) over a six-month period, with rates approaching pre-intervention levels. Other infection control measures remained unchanged. This work adds significantly to the meagre published evidence that environmental contamination is important in the transmission of MRSA. Journal of Hospital Infection. 2011;78(3):243-245.