A method of limiting the spread of the norovirus within a cruise ship comprising: identifying a surface within a common area of a cruise ship that passengers are likely to touch; and applying a silane quaternary ammonium ion or salt thereof to the surface. The common area can be an elevator and the surface an elevator button. The common area can be a stairway and the surface a handrail. The common area can be a casino. The common area can be a dining room. The common area can be a walkway and the surface a handrail. The silane quaternary ammonium ion or salt thereof can be 3-(trimethoxysilyl)propyldimethyloctadecyl ammonium ion, 3-(trimethoxysilyl)propyldimethyloctadecyl ammonium chloride, 3-(trihydroxysilyl)propyldimethyloctadecyl ammonium ion, or 3-(trihydroxysilyl)propyldimethyloctadecyl ammonium chloride. Applying the silane quaternary ammonium ion or salt thereof to the surface comprises applying a solution including the silane quaternary ammonium ion or salt thereof and a solvent.