Once infected, the virus remains in the person for life and my be reactivated from time to time, especially in immunocompromised individuals.
The virus may be transmitted in utero, perinatally, or postnatally. Perinatal transmission occurs.
Perinatal infection is acquired mainly through infected genital secretions, or breast milk. Overall, 2 - 10% of infants are infected by the age of 6 months worldwide. Perinatal infection is thought to be 10 times more common than congenital infection.
Postnatal infection mainly occurs through saliva. Sexual transmission may occur as well as through blood and blood products and transplanted organ.