Background: Herpes simplex virus (HSV) fetal infections are rare, and
the routes through which the virus reaches the fetus are insufficientl
y documented. Case: We describe a case of congenital HSV ascending inf
ection in an infant whose membranes were intact until cesarean deliver
y The pathologic findings were remarkable for a mild lymphoplasmocytic
funisitis and the presence of positive viral staining of cells in the
subamniotic connective tissue, amniotic epithelium, and umbilical cor
d. Antigen-positive cells within the extraplacental membranes were mos
tly located in an area presumably adjacent to the cervix before birth.
In the umbilical cord, positive viral staining was confined to cells
in the subamniotic mesenchyma away from the perivascular mesenchyma of
the central portion of the cord. Conclusion: Immunohistochemistry usi
ng herpes-specific antibodies, coupled with routine histologic examina
tion, allows early diagnosis of congenital HSV infection and documenta
tion of the ascending route of infection when the membranes are intact
.