Fig. 1.

Illustration of the sampling sites and detection process. (a) Layout of the sampling ward. Each room contains 2 beds with chairs and a bedside cupboard. The sampling sites are labeled 1–7. (b) Detection process of the surface contaminants. The test surface was wiped with a wetted cotton swab. The swab was then immersed in 3 mL sodium chloride solution. From this solution, a 5 μL sample was pipetted into the reaction solution.