HSV Flashcards
What are the manifestations of disseminated maternal herpes?
Encephalitis, hepatitis, disseminated skin lesions or a combination
Rare, but more common in pregnancy, particularly if immunocompromised
High maternal mortality
Co-infection with HSV and HIV results in…
Increased replication of both viruses
If HIV positive with history of HSV, management:
Daily suppressive Aciclovir 400mg tds from 32/40
Reduce risk of transmission of HIV, especially if VD is planned
Start early if possibility of PTL
What are the manifestations of congenital herpes?
Skin, eyes, CNS involvement
IUGR
IUFD
What proportion of neonatal herpes is HSV1 vs HSV2
50%
50%
What are factors that increase the risk of HSV transmission in labour?
Primary infection
New infection in third trimester, particularly within 6 weeks of delivery
- viral shedding may persist
- baby is likely to be born before the development of protective maternal antibodies
Duration of ROM before delivery
FBS
Mode of delivery
In maternal HSV, what is the risk of neonatal transmission in
- primary episode in labour
- primary episode in trimester 3, from 28/30
41% with vaginal delivery
Therefore CS recommended
In maternal HSV, what is the risk of neonatal transmission in
- recurrent episode antenatally
- recurrent episode in labour
0-3%
If antenatal: aim vaginal delivery
If antenatal or in labour: offer VS or CS, maternal decision but VD is safe
I
In maternal HSV, what are the recommendations re breastfeeding?
Continue
Unless herpetic lesions around nipple
HSV-1 accounts for what % of genital herpes?
35%
What is the HSV-2 seroprevalence in adult female population?
16%
HSV-1 compared with HSV-2 is:
- Associated with ____ frequent recurrences
- _____ risk of transmission to the neonate at delivery
HSV-1 compared with HSV-2 is:
- Associated with LESS frequent recurrences
- HIGHER risk of transmission to the neonate at delivery
What % of neonates acquire HSV:
- At delivery?
- In-utero?
- Postpartum?
- At delivery 90%
- In utero 5%
- Postpartum 5%
What are potential sources of postnatal HSV transmission to newborn?
- Breast milk
- Skin and oral lesions
- SHV lesions from caregivers, family members or medical staff with close contact.
What is the mortality rate of disseminated neonatal HSV infection?
- 90% if untreated
- 20-30% if treated
What is the indications for Caesarean section delivery to prevent neonatal HSV infection?
- Primary genital HSV during pregnancy particularly third trimester.
- Primary genital HSV diagnosed in labour.
- Active genital herpes lesions and membranes ruptured <6 hours.
- Poor seroconversion following primary HSV infection in first and second trimesters.
When is it safe to offer vaginal delivery when a mother has a history of HSV?
What precautions should you still take in labour?
- History of genital herpes with no active lesions in labour.
- Seroconversion following primary infection in first and second trimesters.
- Avoid trauma to fetal scalp: no FSE, FBS, forceps or ventouse.
- Follow-up neonate
What neonate cares are needed if baby is inadvertently delivered vaginally when there are active genital herpes lesions or following a primary genital herpes episode in the third trimester?
- Empiric IV aciclovir for neonate.
What precautions should be taken when a pregnant seronegative woman has a partner with a history of genital herpes?
- Use condoms.
- Suppressive antiviral therapy for partner.
- Avoid oral sex if partner has oral herpes and HSV type is unknown.
- Abstinence whe symptomatic and during third trimester.
What is the mortality rate of disseminated neonatal HSV infection?
- 90% if untreated
- 20-30% if treated
What is the indications for Caesarean section delivery to prevent neonatal HSV infection?
- Primary genital HSV during pregnancy particularly third trimester.
- Primary genital HSV diagnosed in labour.
- Active genital herpes lesions and membranes ruptured <6 hours.
- Poor seroconversion following primary HSV infection in first and second trimesters.
When is it safe to offer vaginal delivery when a mother has a history of HSV?
What precautions should you still take in labour?
- History of genital herpes with no active lesions in labour.
- Seroconversion following primary infection in first and second trimesters.
- Avoid trauma to fetal scalp: no FSE, FBS, forceps or ventouse.
- Follow-up neonate
What neonate cares are needed if baby is inadvertently delivered vaginally when there are active genital herpes lesions or following a primary genital herpes episode in the third trimester?
- Empiric IV aciclovir for neonate.
What precautions should be taken when a pregnant seronegative woman has a partner with a history of genital herpes?
- Use condoms.
- Suppressive antiviral therapy for partner.
- Avoid oral sex if partner has oral herpes and HSV type is unknown.
- Abstinence whe symptomatic and during third trimester.
What precautions should be taken when a pregnant woman has RECURRENT symptomatic genital HSV?
- Aciclovir suppressive therapy from 36 weeks (or earlier if symptomatic).
- Follow-up for neonate.
What investigations should you order for a pregnant woman with a first episode of genital herpes in pregnancy/labour?
- Type specific PCR and culture (genital swab)
- HSV type specific serology (blood sample)
How would you interpret:
- HSV detect on genital swab BUT
- Same serotype antibody not detected in blood
e. g. HSV1+ swab, HSV1 IgG -ve and HSV2 IgG +ve blood
Non-primary first episode (new acquisition of an HSV serotype with evidence of exposure (IgG +ve) to the other serotype).
Still considered high risk if doesn’t seroconvert prior to 3-34 weeks
How would you interpret:
- Genital swab HSV +ve BUT
- Seronegative for both HSV1 and HSV2 IgG in blood?
Primary first episode.
New acquisition of either HSV serotype without prior exposure (i.e. seronegative in blood to both HSV IgG1 and 2).
What can you infer if a patient has HSV1 antibodies on serology?
Implies prior infection but does not specify site of infection.
How would you interpret:
- Genital swab HSV +ve AND
- Seropositive for same HSV type IgG in blood?
Recurrent infection
What is the effect of prior HSV-1 infection have on acquisition of HSV-2?
- Does not alter risk of acquisition.
- Lessens symptoms of HSV-2
What is the effect of prior orolabial HSV1 infection on genital HSV1?
Prior orolabial HSV1 is protective against genital HSV1.
How to prevent spread of genital herpes
- Condom use (does not eliminate risk).
- Avoid sexual contact when oral or genital lesions present.
- Oral suppressive therapy reduces risk of transmission by 80-95%.
What investigations can be performed for confirming genital herpes?
Highlight any advantages and disadvantages.
Viral PCR swab:
- Gold standard
- Low false positive rate
- Negative test does not rule out HSV.
Viral culture swab:
- High false negative rate.
Type-specific herpes serology (blood):
- Positive antibodies only indicate past (not current) infection.
- Cannot distinguish anatomical site of infection
- No accurate enough.
- Seroconversion rates highly variable.
- Indicated if: discordant couple planning pregnancy (male +ve, female -ve); herpes in pregnancy with no previous history; recurrent or atypical genital sx with negative HSV PCR swab.
What antiviral therapy would you prescribe for:
- First episode
- Recurrent episode
- Suppressive treatment
- First episode: valaciclovir 500 mg BD 7 days or more.
- Recurrent episode: valaciclovir 500 mg BD for 3 days.
- Suppressive treatment: valaciclovir 500 mg OD for 12 months; trial break for 3 months after this.
Outline symptomatic management of genital herpes
- Oral analgesia
- Topical analgesia lignocaine gel 2%
- Sitz baths
- Micturating sitting in bath/bowl of water
- Suprapubic catheter
- Dry lesions with lowest setting of a hair dryer
What are the three subgroups of neonatal HSV?
- Skin, eye and/or mouth
- Local CNS: encephalitis alone
- Disseminated infection with multiple organ involvement
For a woman who has primary episode of HSV diagnosed after 28/40, how long should she take antiviral therapy for?
Aciclovir 400mg tds
UNTIL DELIVERY
Treat without waiting for results
What is a neonatal side effect of mum taking Aciclovir antenatally?
Transient neonatal neutropenia
NO clinically significant adverse effects
