"While HSV-1 in adults can cause the common cold sore, HSV-1 infection in newborns is very serious, " a department statement says.

CNN: Babies' herpes linked to circumcision practice

Since 2000, there have been 13 reports in New York City of infants contracting HSV-1, two of whom died from the virus.

CNN: Babies' herpes linked to circumcision practice

Baby boys whose circumcisions likely involved the ritual between April 2006 and December 2011 had an estimated risk of contracting neonatal HSV-1 infection of 24.4 per 100, 000 cases, 3.4 times greater than other infants, according to the health department.

CNN: Babies' herpes linked to circumcision practice