BEIJING, Feb. 19 (Xinhua) -- The novel coronavirus (COVID-19) can be transmitted when someone was exposed to high concentrations of aerosol in a relatively closed environment for a long time, according to the country's health authorities.

The respiratory droplets and close contact transmission are the major routes of the coronavirus infection, according to the latest version of the diagnosis and treatment plan issued by the National Health Commission and National Administration of Traditional Chinese Medicine on Wednesday.

The aerosol transmission was newly added in the plan, which has been updated to its sixth edition.