Herpes Simplex Virus
|Reviewed by Clinical practice
Herpes Simplex Virus
Only 30% of mothers whose infants have neonatal herpes have a history of
symptomatic genital herpes. Any infant with vesicular lesion(s) must have
investigations performed and have aciclovir treatment commenced regardless of
- Both HSV-1 and HSV-2 can cause neonatal infection. Around 85% of
transmission occurs perinatally, 10% in the postnatal period and a small
- Intrapartum / post natal infection can become manifest up to 4-6 weeks
of age: disseminated infection usually occurs in the first two weeks and can
mimic bacterial sepsis; localised CNS or SEM (skin, eye, mucous membrane)
disease usually becomes manifest during the second and third week.
- The risk of HSV infection in an infant born vaginally to a mother with a
first episode or primary genital infection is 33-50% (hence caesarean
section usually performed) and such infant warrant aciclovir treatment once
investigations have been performed.
- The risk from recurrent genital HSV infection is 3-5% at most and
empiric therapy is not recommended. Cultures can be taken at 24-48 hours if
the infant is asymptomatic and aciclovir only initiated if HSV is
- Scalp electrodes must be avoided wherever there is suspicion of active
HSV in the mother.
- CNS infection may occur as an isolated condition or as part of
disseminated multi-organ disease. In either situation brain involvement may
become extensive and result in adverse outcome. Therefore, in infants
presenting with seizures and no other apparent cause, Herpes Simplex
Encephalitis should be considered and there should be a low threshold for
aciclovir treatment pending the results of CSF PCR.
NB: If these are on a baby with suspected
HSV disease then swabs of skin lesions and other sites should be for PCR, not
culture. If doing surveillance of a non-symptomatic baby born to a mother with
HSV, then culture is sufficient.
- Skin vesicles: swab for HSV PCR.
- Swabs from eyes, mouth / nasopharynx for
- WBCs (CPD or EDTA tube) for HSV PCR.
- CSF - cells, protein, glucose, culture,
- FBC, LFTs
- Head MRI or EEG may assist in localizing
disease but 40 % of babies with disseminated disease will not have CNS
involvement so indication depends on individual cases
- Ophthalmology consultation.
- Consult Paediatric Infectious Disease Team
Contact isolation required, especially if skin lesions present.
Isolate infants born vaginally to mothers with active genital infection for four
weeks. Room-in with mother in isolation if possible. Advise mother re
Observation / Serveillance
Known exposed infants require careful observation.
- Take eye, mouth, nasopharyngeal +/- skin swabs at 24-48 hours for HSV
- The family must be educated regarding the symptoms and signs of neonatal
management of asymptomatic neonates born to women with active genital herpes
lesions. Kimberlin DW, Baley J; Committee on Infectious Diseases; Committee
on Fetus and Newborn. Pediatrics. 2013 Feb;131(2):383-6. doi: