COVID-19 spreads primarily when people are in close contact and one person inhales small droplets produced by an infected person (Could be asymptomatic) coughing, sneezing, talking, or shouting. This is the reason why it is recommended by doctors and governments to follow social distancing norms (i.e maintaining a minimum distance of 1.5 meters).
People can transmit the virus without showing symptoms, but it is unclear how often this happens. People are most infectious when they show symptoms (even mild or non-specific symptoms), but may be infectious for up to two days before symptoms appear (pre-symptomatic transmission). They remain infectious an estimated seven to twelve days in moderate cases and an average of two weeks in severe cases.
When the contaminated droplets fall to floors or surfaces they can, though less commonly, remain infectious if people touch contaminated surfaces and then their eyes, nose, mouth or other parts with mucous membranes with unwashed hands. On surfaces the amount of active virus decreases over time until it can no longer cause infection, and surfaces are thought not to be the main way the virus spreads.
Surfaces are easily decontaminated with household disinfectants which kill the virus outside the human body or on the hands.Disinfectants or bleach are not a treatment for COVID‑19, and cause health problems when not used properly, such as when used inside the human body. One of the best methods of decontamination is direct exposure of sunlight on the infected surface for a period of at least 20 minutes.
Sputum and saliva carry large amounts of virus. Although COVID‑19 is not a sexually transmitted infection, kissing, intimate contact, and faecal-oral routes are suspected to transmit the virus. Some medical procedures are aerosol-generating,and result in the virus being transmitted more easily than normal.
