Viral Infections in Pregnancy Flashcards
What are the general consequences of viral infections during pregnancy (6)
Increased morbidity/mortality/complications for the mother Miscarriage/stillbirth Teratogenicity IUGR/prematurity Congenital disease Persistent infection
What viral infections increase morbidity/mortality/complications for the mother (3)
Influenza
Varicella Zoster
Hepatitis E
What viral infections increase chance of miscarriage/stillbirth (2)
Rubella
Measles
What viral infections increase chance of teratogenicity (2)
Varicella Zoster
Zika
What viral infections cause IUGR/prematurity (2)
CMV
Herpes Simplex Virus
What viral infections cause increase the risk of congenital disease (2)
CMV
HSV
What viral infections cause persistent infections in the child (2)
HIV
Hepatitis B/C
What viral infections are associated with a rash illness (13)
Varicella Zoster (Chickenpox) Epstein Barr Virus HSV Cytomegalovirus Parvovirus B19 (5th disease) Enterovirus Measles Rubella Influenza Hepatitis A, B, C, E HIV HTLV Travel-Associated Viruses - yellow fever, dengue, zika
What are some herpes viruses (4)
HSV
VZV
CMV
EBV
What type of viruses are herpes viruses
DNA viruses
Life-long infections once exposed
What is characteristic about herpes infections
Capacity to reactivate - shingles, recurrent cold sores/genital herpes
What are the two forms of herpes simplex viruses
HSV 1
HSV 2
How is HSV transmitted
Close contact
What is the incubation period of HSV (3)
Oropharyngeal and or-facial infection 2-12 days
Genital infection 4-7 days after sexual exposure
Latency established in nerve cells
What are the symptoms of HSV (4)
Asymptomatic
Painful vesicular rash
Lymphadenopathy
Fever
How is HSV diagnosed (2)
Clinical
Virus detection - culture, antigen detection, PCR, serology
What are the routes of infection of the foetus/neonate in pregnancy (4)
Ascending infection if PROM
Direct contact with infected maternal genital secretions during delivery
Oral herpes in mother post delivery (kissing baby)
Contact with relatives, hospital staff in babies born to susceptible mothers
What type of HSV infection poses the greatest risk to the baby
Primary genital infection in the 3rd trimester poses the greatest risk of transmission to the infant
How is a 1st clinical attack of genital herpes in pregnancy treated (4)
GUM clinic
Aciclovir
Type-specific HSV antibody testing
Caesarean recommended if primary HSV in final 6 weeks of pregnancy
How are recurrent HSV outbreaks managed in pregnancy (2)
Maternal Antibody offers some protection to infants in postnatal period but may not prevent transmission
Prolonged rupture of membranes and invasive fetal monitoring in labour should be avoided
When does neonatal herpes present
3 days - 6 weeks post delivery
How does neonatal herpes present (4)
Lesions of skin, eye, mouth 7-12 days
Neurological symptoms +/- SEM 2-6 weeks
Disseminated disease with/without vesicles frequently involving brain 4-11 days
Mortality in untreated cases of disseminated disease exceeds 80%
How is neonatal HSV diagnosed (2)
Neonatal swabs - oral, rectal, mucosal, umbilical
+/- EDTA blood for HSV PCR
What is the treatment for neonatal HSV
Aciclovir
What are the two presentations of VZV
Chickenpox
Shingles
How is VZV transmitted
Respiratory
70% attack rate in susceptible individuals
Infectious from 48hrs before onset of rash until all lesions have crusted over
What is the incubation period for VZV
7-23 days (mean 2 weeks)
What are the symptoms of VZV infection (3)
prodromal fever, malaise, myalgia (adults>children)
Centripetal maculopapular rash mainly in areas that are not exposed to pressure
Vesicular rash appearing in crops
How is VZV diagnosed (3)
Clinical
vesicle fluid for VZV PCR, (electron microscopy)
NOT serology
What are the foetal complications if the mother catches VZV during early pregnancy
Congenital varicella syndrome
0.4% for maternal infection between 0-12/40
2% for maternal infection between 12-20/40
What does congenital varicella syndrome consist of (8)
Skin scarring Limb hypoplasia Muscular atrophy Rudimentary digits Cortical atrophy Psychomotor retardation Choreoretinitis Cataracts
What is the pathogenesis of congenital varicella syndrome
fetal zoster following initial VZV infection (Short latency due to poorly developed fetal cell-mediated immunity)
What occurs if primary varicella is caught in the 3rd trimester (2)
Severe disseminated haemorrhagic neonatal VZV -purpura fulminans
30% case fatality in untreated cases
How is neonatal varicella contracted if the mother is infected in the 3rd trimester (3)
The route of infection could be transplacental, ascending vaginal or result from direct contact with lesions during or after delivery
What is meant be primary varicella in the 3rd trimester
7 days prior to delivery - 7 days postpartum.
What are the complications of VZV for the mother (2)
Pneumonia
Encephalitis (rare complication - mortality 5-10%)
What increases the risk of pneumonia as a complication in primary VZV in the mother (5)
Mortality?
Smoke cigarettes, Have chronic obstructive lung disease, Are immunosuppressed Have extensive or haemorrhagic rash 2nd half of pregnancy
20-40% case fatality in untreated cases
How is VZV treated in pregnant women (3)
VZV Immunoglobulin
- All pregnant women susceptible to VZV ( irrespective of gestation) with a significant exposure to VZV within 10d
- Infants exposed to chickenpox when <7 days old only if mother VZV IgG negative
Treatment of confirmed VZV - Aciclovir
Vaccination
- Ideally pre-conception counselling should cover varicella Hx if non-immune could delay pregnancy for 2 doses of vaccine.
- Can also vaccinate post-partum if not identified pre-conception.
What proportion of infants are infected with CMV worldwide
2-6% by 6 months
What is the prevalence of CMV in the UK
40% infected by 16 years old
In adults seroprevalance increases by 1% PA
What is the natural history of CMV
Virus persists lifelong in individual, reactivation leads to further transmission (vertical & horizontal) via bodily fluids (eg. nappy-changing)
What are the symptoms of CMV (2)
Most asymptomatic
Rarely maculopapular rash, Infectious mononucleosis-like illness
How is CMV diagnosed (2)
Detection of virus- urine, saliva, amniotic fluid, tissue
Detection of immune response- CMV IgG and IgM
How is CMV transmitted to the foetus in pregnancy (3)
Transplacental
Perinatally- infected genital secretions
Postnatal- saliva, breastmilk
What are the features of congenital CMV infection
Commonest cause of viral congenital infection
Birth prevalence 3/1,000 in the UK
85-90% asymptomatic at birth, but later risk of hearing defects and impaired intellectual performance
What are the main two worries regarding neonatal CMV infection (2)
Hearing defects
Impaired intellectual performance
In symptomatic infants with CMV, what are the features (8)
IUGR Jaundice Hepatosplenomegaly Chorioretinitis Thrombocytopenia Encephalitis Microcephaly/ventriculomegaly/calcifications
How is CMV infection diagnosed
If maternal CMV infection suspected check serology (compare with booking bloods)
If suspected seroconversion during pregnancy refer to fetal medicine unit for USS +/- amnio
Investigating neonates:
Urine/saliva for CMV PCR within 1st 21d
How can we prevent CMV transmission from mother to child
No available treatment
What type of virus is rubella
Togavirus RNA virus
How is rubella transmitted
Respiratory
What is the incubation period for rubella
12-21 days
What are the symptoms of rubella (4)
20-50% subclinical infection
Fine macular rash
Lymphadenopathy
Prodrome may be seen in adult infection
How is rubella diagnosed (2)
Virus isolation
serology
What are the complications of rubella infection in the first trimester (4)
Up to 20% spontaneous abortion if infection before 8/40
90% incidence of fetal defects if infection before 10/40
CRS: cataracts, congenital glaucoma, congenital heart disease, loss of hearing, pigmentary retinopathy, purpura, splenomegaly, microcephaly, mental retardation, meningoencephalitis
CRI: infants without CRS clinical signs but with positive rubella specific IgM
In infants with congenital rubella syndrome, how long are they infective for
Up to and over 1 year
What is CRI
Congenital Rubella Infection
What is CRS
Congenital Rubella Syndrome
What are the consequences of rubella infection after the 1st trimester (2)
13-18/40 hearing defects and retinopathy
Maternal infection after 20 weeks carries no documented risk
When is rubella vaccinated for in the UK
MMR x 2 (13 months and pre-school booster)
What causes the majority of the causes of rubella in the UK now
Most cases are imported
What viruses are associated with a rash (8)
Varicella Zoster Virus (chickenpox) Epstein Barr virus HSV Cytomegalovirus Parvovirus B19 ( 5th disease) Enterovirus Measles Rubella
How is measles transmitted (2)
Respiratory
Conjunctiva
What is the incubation period for measles
7-18 days (typically 10 days)
What are the symptoms of measles (2)
prodrome 2-4 days- fever, malaise, congestion, conjuctivitis, koplik’s spots
Rash classically starts behind ears & on forehead then spreads
Where does the measles rash typically start
Rash classically starts behind ears & on forehead then spreads
What are the complications of measles (3)
Opportunistic bacterial infections (otitis media, pneumonia, bronchitis)
Encephalitis
SSPE
What are the consequences of measles infection in pregnancy (4)
Fetal loss (miscarriage, IUD)
Preterm delivery
Increased maternal morbidity
No congenital abnormalities to fetus
What is the treatment in susceptible pregnant women is contact with suspected/confirmed measles (2)
Measles Immunoglobulin attenuates illness
No evidence it prevents IUD or preterm delivery
How is parvovirus B19 transmitted (2)
Respiratory
Blood Products
What is the incubation period for parvovirus B19
6-8 days
What are the symptoms of parvovorius B19 (4)
Asymptomatic
Erythema infectiosum/ slapped cheek/ 5th disease
How is parvovoris B19 diagnosed (2)
Serology
Molecular tests
When during pregnancy are there increased risks to maternal infection with B19
Before 20/40
No documented risk after 20/40
What are the risks of parvovorus B19 infection before 20/40 (4)
Transplacental transmission estimated at 33%
9% risk of infection overall
3% risk of hydrops fetalis if infection from 9-20/40
Risk of foetal anomalies less than 1%
What is the management of maternal infection with parvovirus B19 during pregnancy (2)
Refer to foetal medicine for monitoring
Intrauterine transfusion improves foetal outcome
What are some human enteroviruses (3)
Polio
Coxasackie A and B
Echovirus
What RNA do enteroviruses have
Pocornaviridae
How is enterovirus transmitted (2)
Respiratory
Fecal
What is the incubation period for enterovirus
2-40 days
What are the symptoms of enterovirus infection (4)
Hand, foot and mouth disease
Rash illness
Encephalitis
Myocarditis
What is coxasackie infection in pregnancy associated with (5)
Early onset neonatal hepatitis
Congenital Myocarditis
Early onset childhood IDDM
Abortion or intrauterine death
What type of virus is zika virus
Flaviviridae RNA
Is Zika always symptomatic
No, 8/10 are asymptomatic
How is Zika transmitted (4)
Mostly from mosquitos
Pregnancy
Sexual intercourse
Blood transfusions
Where is Zika virus most prevalent
South America
What neurological condition can Zika cause
Guillain Barre Syndrome
What are the symptoms of Zika virus (6)
Red eyes Fever Joint pain Headache Rash Muscle pain
What are the consequences of zika infection during pregnancy (2)
Miscarriage/stillborn/microcephaly
Congenital Zika syndrome
What does congenital zika syndrome consist of (5)
Severe microcephaly + skull deformity Decreased brain tissue, seizures Retinopathy, deafness Talipes Hypertonia
What are the top travel locations associated with zika infection (3)
Caribbean
Central/South America
what advice is given to people to prevent zika (4)
All travellers – bite avoidance
Pregnant women – avoid travel to areas with current transmission
Avoid conception for 2 – 6 months after
travel (prolonged viral shedding in semen)
Testing only if symptomatic or abnormalities identified on antenatal USS
