The causative agent or pathogen of Epstein Barr Virus (EBV) is the herpes virus.
People infected with the Epstein Barr virus will retain it for life, however it may not make them sick. It is spread mainly via the transfer of saliva between individuals, which is the reason that glandular fever (or infectious mononucleosis, which is the first stage of the EBV) has been dubbed the ‘kissing disease’.
Most people become infected with EBV during their lives. Infants become susceptible to EBV as soon as maternal antibody protection (present at birth) disappears. Many children become infected with EBV, and these infections usually cause no symptoms or are indistinguishable from the other mild, brief illnesses of childhood. At early stages, the virus causes no harm to humans. However, as it continues to replicate in our body, it destroys our immune system and therefore can be very harmful. It could cause a more dangerous disease, which sometimes could cause death.