Paradoxical Increase in Methicillin-Resistant Staphylococcus aureus Acquisition Rates Despite Barrier Precautions and Increased Hand Washing Compliance during an Outbreak of Severe Acute Repiratory Syndrome

Abstract
SIR—We read with interest the report by Yap et al. [1] regarding the increased rates of methicillin-resistant Staphylococcus aureus (MRSA) isolation in the intensive care unit (ICU) during an outbreak of severe acute respiratory syndrome (SARS) in Hong Kong. The SARS outbreak in Singapore, which lasted from 4 March 2003 to 11 May 2003, also led to the adoption of heightened infection-control measures, including mandatory universal use of personal protective equipment (PPE) consisting of disposable long-sleeved gowns, gloves, goggles, and N95 masks by health care workers for all patient contacts. Compulsory training on the proper donning and discarding of PPE was instituted, and compliance with hand washing was reinforced. Observers were employed to ensure that these measures were followed by the ward staff. In addition, all patients with undifferentiated fever were nursed in single isolation rooms until the cause of their fever was ascertained. Whereas the data reported by Yap et al. [1] was confined to the ICU, we studied the effect of these measures on hospital-wide nosocomial MRSA infection and bacteremia rates in the National University Hospital, a 1000-bed teaching facility in Singapore.