Neonatal Herpes Simplex (1)
Incidence of neonatal HSV infection varies inexplicably from country to country e.g. from 1 in 4000 live births in the U.S. to 1 in 10000 live births in the UK
The baby is usually infected perinatally during passage through the birth canal.
Premature rupturing of the membranes is a well recognized risk factor.
The risk of perinatal transmission is greatest when there is a florid primary infection in the mother.
There is an appreciably smaller risk from recurrent lesions in the mother, probably because of the lower viral load and the presence of specific antibody
The baby may also be infected from other sources such as oral lesions from the mother or a herpetic whitlow in a nurse.