CD40LG and Epstein-Barr virus infection: The youngest infant with a primary EBV infection having the pattern of [VCA-IgM+, low affinity VCA-IgG+, EBNA-IgG+, VCA-IgG– and EA-IgG–] was only 1 month old, and this was probably caused by an intrauterine or intrapartum infection.