A fomite is an object that carries/spreads infections agents. A common fomite is a door knob. Many people leave bacteria or viruses behind when they touch door knobs. Without proper cleaning people also take vectors (bacteria or viruses) with them. For fomite transmission to occur the vector needs to be undamaged. If the vector is damaged by either heat or disinfectant then the next person to touch the door knob will not be infected. This makes proper cleaning and disinfecting vital to prevent the spread of droplet spread diseases. Fomite transmitted viruses cause the common cold and the flu. This is why with the new cleaning guidelines in place in various venues many people have avoided catching a cold or a flu during the pandemic.
Although many illnesses are caused by fomite transmission SARS Cov-19 is not one of them. Covid 19 is transmitted via aerosol transmission. This means that it is transmitted via small aerosol particles in the air. People can contract it by breathing in the same room as someone who is spreading the virus. People who are infected came into contact with the virus in the air. In the case of Covid 19 the best way to protect yourself is to wear a tightly fitted mask that filters out the small aerosol particles that are in the air. Each layer of the mask filters out some particles while letting air through. Masks with more layers filter out more particles. If each layer filters out 25% of the particles, four layers would be required to filter out all of the particles. If the mask is ill fitted then air will enter and exit through the gaps around the mask instead of going through the filter because that it is the path of least resistance.
Kraay, A.N., Hayashi, M.A., Hernandez-Ceron, N. et al. Fomite-mediated transmission as a sufficient pathway: a comparative analysis across three viral pathogens. BMC Infect Dis 18, 540 (2018). https://doi.org/10.1186/s12879-018-3425-x
Applied Plant Ecology Winter 2020 