What causes Mononucleosis?
Infectious mononucleosis is spread through immediate contact with saliva, hence the colloquial name "kissing disease". Sharing eating utensils is another way to transmit mononucleosis.
Contact through air or blood does not spread mononucleosis.
Even long after having been exposed to the virus and any acute symptoms are gone, people still carry the virus. They are typically not at risk of reinfection but are at risk of infecting others. Because so many people have been infected with the virus, prevention from exposure is near impossible. </s>