https://www.ucsf.edu/news/2020/02/4...progresses-and-why-one-test-may-not-be-enough
The new coronavirus is spread through droplets and surfaces.
The principal mode of transmission is still thought to be respiratory droplets, which may travel up to six feet from someone who is sneezing or coughing. The new coronavirus isn’t believed to be an airborne virus, like measles or smallpox, that can circulate through the air. “If you have an infected person in the front of the plane, for instance, and you’re in the back of the plane, your risk is close to zero simply because the area of exposure is thought to be roughly six feet from the infected person,” said Chiu.
http://kanehealth.com/Documents/Diseases/Ebola-infections-spread-by-air-or-droplets.pdf
https://en.wikipedia.org/wiki/Transmission_(medicine)#Airborne_infection
Airborne infection
"Airborne transmission refers to infectious agents that are spread via droplet nuclei (residue from evaporated droplets) containing infective microorganisms. These organisms can survive outside the body and remain suspended in the air for long periods of time. They infect others via the upper and lower respiratory tracts."
[10] The size of the particles for airborne infections need to be < 5 μm
[11]. It includes both dry and wet aerosols and thus requires usually higher levels of isolation since it can stay suspended in the air for longer periods of time. i.e., Separate ventilation systems or negative pressure environments are needed to avoid general contamination. e.g
Droplet infection
"Droplet transmission occurs when respiratory droplets generated via coughing, sneezing or talking contact susceptible mucosal surfaces, such as the eyes, nose or mouth. Transmission may also occur indirectly via contact with contaminated
fomites with hands and then mucosal surfaces. Respiratory droplets are large and are not able to remain suspended in the air thus they are usually dispersed over short distances."
[12] The size of the particles for droplet infections are > 5 μm
[11]. Droplet infections are usually transmitted by wet droplets and thus are less likely to stay
Organisms spread by droplet transmission include respiratory viruses (e.g.,
influenza,
parainfluenza virus,
adenovirus,
respiratory syncytial virus,
human metapneumovirus),
Bordetella pertussis,
pneumococci,
diphtheria, and rubella.
[13]