Herpes Simplex Virus Flashcards

1
Q

Define

A

DNA virus

Two types: 1 (oral>genital) or 2 (genital>oral)

Spread to neonate – through direct contact with infected maternal secretions (transplacental possible), risk of neonatal transmission at vaginal delivery is 41% with primary lesion or 2% with recurrent lesions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Risk factors

A

Aetiology: physical/sexual contact; vertical

Risk factors: unprotected sex, immunosuppression, other STI

Factors influencing transmission:

  • Type of maternal infection (primary or recurrent)
  • Primary episode- 57% risk of neonatal infection
  • First episode non-primary- 25% risk
  • Recurrent episode(s)- 2% risk

Presence of transplacental maternal neutralising antibodies

Duration of rupture of membranes before delivery

Use of foetal scalp electrodes/ integrity of mucocutaneous barriers

Mode of delivery

  • Vaginal- increased risk
  • C-section- PREFERRED

Epidemiology: 2% of pregnant women

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Signs and Symptoms

A

Maternal:

  • Asymptomatic
  • Oral herpes
  • Genital herpes (dysuria, frequency)
  • Disseminated herpes (encephalitis, hepatitis, disseminated skin lesions)

IU HSV infection

  • Microcephaly
  • Encephalomalacia
  • Hydranencephaly and/or intracranial calcification
  • Scarring, active lesions, hypo- and hyperpigmentation
  • Microphthalmia, retinal dysplasia, optic atrophy and/or chorioretinitis

Neonatal: 1 per 60,000 live births -> SEM (skin, eyes, mouth) , CNS ± SEM or disseminated infection:

Skin, Eye and Mouth (SEM) disease - 45%

  • Blistering vesicular rash
  • Chorioretinitis

CNS disease ± SEM 30%——— Mortality 6% (high morbidity)

  • Seizures
  • Lethargy
  • Presents 10d-4w postpartum
  • Irritability
  • Poor feeding
  • Temperature instability
  • Bulging fontanelle

Disseminated infection involving multiple organs 25%——— High mortality (30%)

  • Encephalitis (60-70%)
  • CNS (60-75%)
  • Hepatitis
  • Pneumonitis
  • No skin lesions (>20%)
  • DOC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Investigations

A

Clinical diagnosis ± STI screen

PCR virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Management

A

ACUTE INFECTION  Aciclovir (400mg, TDS):

  • Maternal:
  • <26w primary infection -> oral aciclovir; 36 weeks until delivery
  • >26w primary infection -> oral aciclovir until delivery

Neonate:

  • IV aciclovir to child (14d if SEM disease -> 21d if CNS or disseminated)

+ monitor neutrophil count

DELIVERY (primary infection):

1st episode ≥6w prior to EDD -> SVD

1st episode ≤6w prior to EDD -> C-section

Perform HSV (type-specific) antibody testing

If the woman chooses vaginal delivery:

  • Rupture of membranes and invasive procedures should be avoided
  • IV aciclovir given intrapartum to the mother (and the neonate)
  • Avoid invasive procedures in labour (e.g. forceps delivery) -> increase risk of neonatal HSV

DELIVERY (recurrent episodes) -> SVD (only a 2% risk of transmission if recurrent; due to maternal IgG)

  • Daily suppressive aciclovir 400mg TDS from 36 weeks’ gestation
  • Avoid invasive procedures during labour if genital lesions (i.e. foetal scalp electrodes)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Complications

A

Herpes is particularly dangerous when acquired around the time of delivery, with serious neonatal consequences

Premature rupture of membranes and preterm delivery

Prognosis -> neonatal mortality from 2% (local disease) to 50% (disseminated disease)

  • Improved outcomes if early diagnosis and initiation of antiviral therapy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly