How It Spreads
The primary mode of transmission is via respiratory droplets that people exhale, for example when coughing or sneezing. Droplets stay suspended in the air for only a short time but may stay viable and contagious on a metal, glass or plastic surface. Details for the virus are not available as of 26 February 2020, and it is assumed that they are similar to other coronaviruses, which survive for up to nine days at room temperature.[180] Disinfection of surfaces is possible with substances such as 62–71% ethanol applied for one minute. The WHO has stated that the risk of spread from someone without symptoms is "very low." However, if someone has beginning symptoms and a mild cough, there is a risk of transmission. In addition, an analysis of infections in Singapore and Tianjin in China revealed that many coronavirus infections may be spread by people who have recently caught the virus and have not yet begun to show symptoms. This finding means that isolating people once they start to feel ill is less effective than hoped.[182]