Prevention and management of neonatal herpes simplex virus infections

Question 1

What are the types of HSV infection and the risk of transmission?

Answer 1

First episode primary infection: 60% (mom seronegative)

First episode non-primary infection: 30% (mother has a new infection with one virus type, in the presence of cross-reacting antibodies to the other virus type)

Recurrent: 2% (seropositive)

The category of maternal infection at time of delivery influences the likelihood of NHSV acquisition, presumably because mothers who have had an HSV infection transmit HSV-neutralizing antibodies to their infant across the placenta, provided that their infant is not born 75% acquired during delivery with new/asymptomatic genital disease, but can be in utero or postnatal)

(In most cases of NHSV infection, there is no known history of maternal genital HSV because mothers have never had or have never noticed external genital lesions. Studies show that 75-90% of individuals who are seropositive for HSV-2 were unaware of their infection)

Question 2

What are risk factors that increase transmission?

Answer 2

Related to viral shedding at delivery

ROM duration (>6hrs), use of fetal scalp electrodes, route of delivery (do C/S if active lesions, reduce transmission by 86% as long as ROM can lower recurrence of genital HSV and shedding at delivery