SYMPTOMS
AIR
A viruses can spread through air. When body liquids are produced, air can be a medium. Most common it's about coughs, but also feces and vomit can contain high concentrations of viruses too. With the outbreak of SARS in Hong Kong, one high rise building got infected due to a leak in the sewage system (Hung, 2003). At cafes, pubs and events extra attention could be given to toilets considering people might also vomit there in case they got too much alcohol. There are papers showing how ionizing air can limit the spread of a virus with air as its medium (Estola, 1979). Ironically enough the device to ionize the air with is called a 'Corona discharge'.
PEOPLE
Once a new virus found a human host, it can spread human to human. Personal hygiene and the way we interact are factors indicating how quick and how far it spreads.
SURFACES
A virus can remain alive on a surface. Usually this is not a threat because the risk is very low the virus remained contagious as soon it is transferred by your hands. But in places where many different people use the same surfaces frequently this risk increases. Apart from the product interactions mentioned earlier on this page, touching of a surface could also be an opportunity to clean hands of people. By supplying its surface with a sterilizer, a door handle could become a tool to limit the spread of a virus instead of a cause. UV light might also help to clean surfaces.
Sources:
The SARS epidemic in Hong Kong: what lessons have we
learned? Lee Shiu Hung, J R Soc Med 2003; 96:374–378
Timo Estola, The effect of air ionization on the air-borne transmission of experimental Newcastle disease virus infections in chickens, J. Hyg., Camb. (1979), 83, 59 59