Viral Infections in Pregnancy Flashcards
List the herpes viruses with their numbers
HSV 1 - oral and genital
HSV 2 - genital
Herpes virus 3 - VZV (Z has three lines)
4 - EBV (Barr has four letters)
5 - CMV - (C and 5 look similar)
6 and 7 - roSeola (6 and 7 start with s)
8 - Kaposi’s virus
What kind of virus is herpes?
DNA virus
What is the incubation period for oropharyngeal herpes viruses?
2-12 days
What is the incubation period for genital herpes?
4-7 days
What are the symptoms of HSV1/2? How do you diagnose it?
Painful vesicular rash
Can also be asymptomatic
Lymphadenopathy
Fever
Take a swab for PCR
What are the ways in which HSV1/2 can be transmitted to babies?
Foetal transmission - due to ascending infection from PROM, sometimes the mother may be asymptomatic.
Neonatal vertical transmission - during delivery.
What are the consequences of foetal transmission?
IUGR
Preterm delivery
Miscarriage
Congenital abnormalities
What congenital abnormalities can arise from herpes transmission?
Ventriculomegaly
CNS problems
What can be done if herpes infection is suspected in a pregnant mother? When is the risk of transmission the greatest?
Risk worst during 3rd trimester
If suspected at 6 weeks before delivery:
- screen for other STDs at GUM clinic
- start acyclovir + + paracetamol and topical lidocaine 2% gel
- CHECK HSV1 ANTIBODY as it can provide some protection but doesn’t fully prevent transmission
- plan for a c-section
- avoid prolonged ROM or instrumental usage
What can be done if a mother has recurrent herpes infections? What is the management?
Consider suppressive therapy after 36 weeks; aciclovir 400mg TDS
Supportive treatment - saline bathing and paracetamol
Usually can have vaginal delivery as risk of transmission is low
What is the risk of mortality in untreated neonatal HSV?
Over 80 percent of children DIE, and there is severe neurological involvement.
How does HSV present in young children? Mild-moderate symptom progression
Initially benign - Skin, eye and mouth involvement; high risk of progresses to CNS
CNS involvement
Disseminated sepsis
What CNS symptoms do neonates present with?
CNS involvement
- seizures, lethargy, irritability, poor feeding, fevers
When do neonates present with CNS HSV?
Up to first 6 weeks of life
When do neonates present with SEM?
Within first 14 days, up to 6 weeks
When do neonates present with disseminated sepsis HSV?
Within 1st week of life
How does VZV present in adults?
If they had chickenpox, it presents as a unilateral dermatomal rash (can also progress to encephalitis, mengitis, myelitis - spine pain)
If not, it can cause varicella pneumonia (very bad)
How is VZV transmitted? How transmissible is it?
Respiratory droplets; 70% of people who have never had chickenpox before can get it if in a room with someone with chickenpox
When are you infectious with varicella?
24 hours before the rash
5-7 days after the rash OR after the rash has crusted over
In women who have not had chickenpox before and get pregnant, what is the risk for mum and baby?
Maternal varicella:
They can get varicella pneumonia
Varicella encephalitis (rare but 10 percent mortality)
Congenital varicella syndrome (higher risk in second trimester)
What are the symptoms of congenital varicella syndrome?
Neuro abnormalities
Skin scarring
Limb abnormalities
GI abnormalities
Occular abnormalities
A woman comes in saying she’s pregnant and came into contact with someone with chickenpox. What do you ask her? If she says no, what do you do?
Has she had chickenpox previously?
Has she had TWO doses of varicella vaccine?
If not, do an urgent antibody testing
What do you test for on a varicella antibody screen? What level are you aiming for?
VZV igG above 100mlU/ml
If the VZV IgG is less than 100mlU/ml, what do you do?
If presenting within 7 days of exposure, offer until day 14 after exposure
Look at green top guidance
Give aciclovir 800mg TDS OR valaciclovir 1000mg TDS 3
If presenting after 7 days since exposure:
800mg oral aciclovir QDS OR
1000mg oral valaciclovir TDS
until day 14 post exposure
If presenting within 7 days since exposure of VZV, what do you offer the woman?
Look at green top guidance
Give aciclovir 800mg TDS OR
Valaciclovir 1000mg TDS
until 2 weeks after exposure
If presenting after one week since exposure to VZV, what do you give?
If presenting after 7 days since exposure:
800mg oral Aciclovir QDS OR
1000mg oral valaciclovir TDS (this is correct, TDS)
until day 14 post exposure
CMV - which herpes virus number is this?
Herpes virus 5
Who gets affected by CMV?
Everyone gets CMV - very common early childhood infection, however only really problematic if immunocompromised or pregnant
CMV route of transmission
Saliva, respiratory secretions, urine (changing nappies)
CMV symptoms
Infectious mono-nucleosis type symptoms
Mostly asymptomatic
Diagnosis of CMV
PCR of saliva, urine, tissue, amniotic fluid
Serology
When is CMV transmission risk worst?
3rd trimester
If you suspected varicella meningitis, what bedside tests could you do? Explain these two tests.
Kernig’s test - Straightening the leg after hip and knee flexion causes back pain (irritation in the meninges)
Brudzinski’s test - passive head flexion causes involuntary hip flexion
