Characterizing dynamic transmission of contaminants on a surface touch network

Our understanding of the fomite transmission route of diseases remains at an empirical level. There are no data on how surface contamination is propagated by human touching. We designed a novel and effective benchtop experiment to investigate the dynamic transmission of contaminants on multiple environmental surfaces due to touching. The benchtop experiment setting design was based on an inflight norovirus outbreak. Hundreds of representative environmental surfaces in the plane were scaled down, and fluorescent particles were used as surrogate indicators of virus-laden aerosols. The fluorescent particles were initially carried by six index “patients” and then transmitted to other surfaces through the touching behavior of one hundred and twenty-four “passengers.” The distributions of fluorescent particles were photographed by cameras when exposed to UV light and the acquired photos were processed using fluorescence imaging techniques to quantify fluorescent particles on each surface. The temporal diffusion of contaminated surfaces was found to follow an S-shaped logistic curve. The aisle seats were found to be more contaminated, which was consistent with the reported higher attack rates in passengers seating along the aisle in the outbreak. This study confirmed the findings of the logistic growth from the multi-agent simulations, and provided a possible mechanism for the role played by environmental surfaces in the fomite route of diseases.