Epidemiology and Pathogenesis
HHV-6 and HHV-7 are ubiquitous and are found worldwide.
They are transmitted mainly through contact with saliva and through breast feeding.
HHV-6 and HHV-7 infection are acquired rapidly after the age of 4 months when the effect of maternal antibody wears off.
By the time of adulthood, 90-99% of the population had been infected by both viruses.
Like other herpesviruses, HHV-6 and HHV-7 remains latent in the body after primary infection and reactivates from time to time.