This living lab case study on antimicrobial surfaces was done at an elementary school in Lieto during spring 2018. Antimicrobial surfaces can be used to minimize the amount of malign microbes thus reducing pathogens.
This study was commissioned by Isku Interior Oy and microbial testings were made during March and April 2018. Samples were collected on six different times. The tests included total viable count, gram-negative bacteria on MacConkey agar, Enterobacteriaceae and Staphylococcus aureus tests on culture plates and verification with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Noro and adenoviruses were tested with separate sampling. Surface hygiene was tested with ATP measuring device. The effect of antimicrobial surfaces on short term sick leave was studied using un-personified absence data from the school from a period of six months.
The quantitative results from the culture plates were low both on antimicrobial and comparison surfaces. Visually the quantitative results showed lower amount of microbes on antimicrobial surfaces. Studied desk, chair, teacher’s chair, door handle and washbasin results show no statistical significance on confidence level 95 % between antimicrobial and comparison surfaces when t-test and one-way-ANOVA was run. The chair frame results showed that surfaces had statistical significance on confidence level 95 %. On qualitative analysis of bacteria, no Enterobacteriaceae or Staphylococcus aureus were found. Some strains of opportunistic pathogens was found on MacConkey agar. Adenovirus was found on door handle on one sample. ATP-measurements were also low and surfaces were not especially dirty. There were no statistical correlation between ATP and quantitative microbe results. When the absence data was studied, it showed that there was difference between class rooms.