Figure 1.

Diagram of construction. In our hospital, the 4th floor intensive-care unit was reconstructed from September 2013 to May 2014. Nurse call speakers were also repaired in the 8th floor hematology ward in December 2013. In addition, two large clean rooms for four patients in the hematology ward were constructed internally from January 2014 to February 2014. A partition was installed between the patient area and construction site. The source of the outbreak was suspected to be the construction area on the 4th floor, which did not have a sufficient negative pressure system to remove dust from construction workers. A unit with a negative pressure system was subsequently constructed beside the construction area in January 2014.