Virology

Question 1

Which viral infections have an increased severity in pregnant women?

Answer 1

Influenza- VT
Measles-SC
Varicella-VT
Primary HSV-VT
Hepatitis E-SC

• VT-viral therapy
• SC-supportive care

Question 2

Which infections are transmitted anterpartum(not long before birth)?

What are the effects of these feotal infections?

Answer 2

Rubella
CMV
HIV
VZV
Zika
Parvovirus

Abortion
Stillbirth
IUGR-Intrauterine growth restriction
Congenital malformations

Question 3

Which infections spread intrapartum(blood and birth canal)?

Answer 3

CMV
HIV
HSV
HPV
HBV
HCV
Enterovirus

Question 4

Which viruses spread postpartum(breastfeeding and environment)?

What are the effects of the neonatal infection?

Answer 4

Breastfeeding

• HIV
• HBV
• CMV
• HTLV(human T-lymphotropic virus)
• acute disease
• asymptomatic
• late sequelae(HSV, enterovirus from environment)

Question 5

How does the maternal rubella present?

Answer 5

• Normally mild or asymptomatic
• Maculopapular rash from face downwards
• Posterior cervical lymphadenopathy
• Joint pains

Question 6

What Is the pathogenesis of congenital rubella ?

What effect does this have on the fetus?

Answer 6

It limits growth and division of cells, and thus that of developing organs such as

• heart
• brain
• eyes
• ears
• liver
• spleen
• bone marrow

Fetus death
Malformation i.e. congenital rubella syndrome
Late sequelae

Question 7

Discuss the congenital rubella syndrome triad

Answer 7

• Sensorineural deafness
• Cataracts and other opthalmic abnormalities
• heart defects eh PDA, PAS, VSD
• neurological sequelae
• microcephalic, meningiocephalitis, behaviour disorders, mental retardation

Question 8

Name the risk factors of congenital rubella

Answer 8

In Maternal primary infection:

• 1st trimester-80% abortion or multiple congenital defects
• 2nd &3rd trimester- single congenital defect esp deafness
• higher GA= less risk

In re-infection:
-8% in 1st trimester

Question 9

How is maternal rubella(and maternal CMV) diagnosed?

Answer 9

Serology test(ELISA) to look for antibodies:

• IgM- IgG- No infection
• IgM+ IgG- Primary infection (must be confirmed by seroconversion)
• IgM- IgG+ Exposure but Immunity
• IgM+ IgG+ Primary or re-infection( perform IgG avidity test)

Question 10

Describe the IgG avidity test

Answer 10

Used to measure the binding ability of IgG to the virus

• low avidity (<30%)= primary infection
• high avidity(>60%)= reinfection

Question 11

How is foetal rubella(and foetal CMV) diagnosed?

Answer 11

• amniotic fluid PCR
• cordocentesis(foetal blood) PCR and IgM (21 weeks)
• ultrasound for multiple abnormalities

*if initial test is negative, test again at 21 weeks GA or 2 months after maternal infection

Question 12

What does igM from the newborn indicate when found before and after 10days post partum ?

Answer 12

IgM before 10 days
- Foetal origin

IgM after 10 days
- Foetal or early neonatal origin

Question 13

How can rubella be prevented?

Answer 13

MMR live attenuated vaccine

*contra-indicated in pregnancy but has low risk

Question 14

How does maternal CMV present?

Answer 14

Normally asymptomatic and latent until reactivated later on in life

Question 15

What is the pathogenesis of foetal CMV?

Answer 15

Allows organs to develop normally and then later on destroys them and makes them dysfunctional

Question 16

Describe the risk level of CMV

Answer 16

Primary infection has a worst outcome for foetus than reactivation

*infection leads to damage only 10% of the time

Question 17

What are the signs and
Symptoms of CMV inclusion disease?

What is the classic triad?

Answer 17

• IUGR- SGA/LBW
• hepatosplenomegaly and hepatitis
• thrombocytopenia and anemia
• Petechial skin rash(blueberry muffin)
• seizures and deafness
• pneumonitis and myocarditis
• cerebral calcifications
• microcephaly
• chorioretinitis and other eye conditions

Question 18

List the sequelae of CMV infection

Answer 18

• hearing, visual, neuro, dental defects
• learning disabilities
• delayed psychomotor development

Question 19

Name the results of CMV PCR test

What does a high Viral load indicate?

Answer 19

Before 3 weeks postpartum= congenital infection
After 3 weeks postpartum= congenital, perinatal, post natal

Increased risk of hearing loss or other sequelae

Question 20

What is the Parvovirus B19 pathogenesis?

Answer 20

It targets RBC precursors; therefore anemia
It targets myocardial cells therefore myocarditis

*both these lead to cardiac failure, hydrops fetalis

Question 21

List the effects of parvovirus during pregnancy and after birth

Answer 21

1st and 2nd trimester:

• miscarriage
• severe anemia
• hydrops fetalis

After birth:
No congenital malformations

Question 22

Discuss the diagnosis of parvovirus

Answer 22

• cordocentesis PCR or IgM or Hb
• Hb<5 consider intra-uterine blood transfusion
• ultrasound-big oedematous baby (do follow up US every week 12 to 18 weeks after maternal infection)

Question 23

What is the maternal VZV mortality?

Answer 23

Mortality>40% if not treated with acyclovir

Question 24

What is the risk rate of congenital Varicella syndrome?

Answer 24

1-2% in the first 20 weeks