TRANSMISSION

COVID-19 is a new disease, and the ways it spreads between people are under investigation, including: the predominant role of small droplets, the extent to when and how it may be transmitted through air, and how long expelled droplets remain infectious on surfaces.

The disease is spread during close contact, often by small droplets produced during coughing, sneezing, or talking. During close contact, (1 to 2 metres, 3 to 6 feet), people catch the disease after breathing in contaminated droplets that were exhaled by infected people. However, the droplets are relatively heavy and usually fall to the ground or surfaces, as opposed to being infectious over large distances.

After the droplets fall to floors or surfaces, they still can infect other people, if they touch contaminated surfaces and then their eyes, nose or mouth with unwashed hands. On surfaces the amount of active virus decreases over time until it can no longer cause infection. However, experimentally, the virus can survive on various surfaces for some time, (for example copper or cardboard for a few hours, and plastic or steel for a few days). 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 inside the human body.

Sputum and saliva carry large amounts of virus. Some medical procedures may result in the virus being transmitted easier than normal for such small droplets, known as airborne transmission.

The virus is most contagious during the first three days after onset of symptoms, although spread is known to occur up to two days before symptoms appear (presymptomatic transmission) and in later stages of the disease. Some people have been infected and recovered without showing symptoms, but uncertainties remain in terms of asymptomatic transmission.

Although COVID-19 is not a sexually transmitted infection, kissing, intimate contact, and faecal oral routes are suspected to transmit the virus.