Regarding the most recent question to the list on MRSA infections, users could read these articles:

Mohammed MA, Worthington P, Woodall WH. Results of a multicentre randomised controlled trial of statistical process control charts and structured diagnostic tools to reduce ward-acquired meticillin-resistant Staphylococcus aureus: the CHART Project.J Hosp Infect. 2008 Oct;70(2):127-35. Epub 2008 Aug 23.

Curran E, Harper P, Loveday H, Gilmour H, Jones S, Benneyan J, Hood J, Pratt R. Results of a multicentre randomised controlled trial of statistical process control charts and structured diagnostic tools to reduce ward-acquired meticillin-resistant Staphylococcus aureus: the CHART Project.J Hosp Infect. 2008 Oct;70(2):127-35. Epub 2008 Aug 23.

Borckardt JJ, Nash MR, Hardesty S, Herbert J, Cooney H, Pelic C. How unusual are the "unusual events" detected by control chart techniques in healthcare settings? J Healthc Qual. 2006 Jul-Aug;28(4):4-9.

regards Jens Lauritsen EpiData Association