The virus is spread horizontally by either the oral-fecal route or by the respiratory route.

Some may be transmitted to humans through a respiratory route.

The most frequent is the respiratory route.

Transmission of caliciviruses is generally by the fecal-oral route but can also be transmitted via the respiratory route.

Although there is no evidence to suggest that prions travel through air and are infectious via a respiratory route, they are treated as dangerous particles.

Transmission is horizontal, via oro-fecal or respiratory routes.

Also known as the respiratory route, it is a typical mode of transmission among many infectious agents.

It is found in respiratory secretions suggesting that it may be transmitted by a respiratory route.

While older research dealt with the skin route, recent research has increasingly favored the respiratory route.

In summary, entry through the respiratory route appears the most probable route, although other routes, particularly broken skin, cannot be ruled out.