Clinical features of different viruses

Question 1

What type of virus is varicella zoster?

Answer 1

Herpes virus, DNA virus

Question 2

How is varicella zoster spread?

Answer 2

By close contact and droplets

Question 3

How is varicella zoster virus transmitted in pregnancy

Answer 3

Maternal infection> maternal viraemia> virus transferred across the placenta> fetus recovers from initial infection> virus reactivates and acts like Zoster attacking the dermatomes

Question 4

What are the physical consequences of varicella embryopathy?

Answer 4

Skin - scarring, hypopigmentation, hyperpigmentation
Limbs - hypoplasia and rudimentary digits
eyes - chorioretinitis, eye defects, cataracts
brain - cortical atrophy
Head - microcephaly

Question 5

When should the varicella vaccination be given?

Answer 5

Pre natally or postpartum not antenatally as it is a live attenuated vaccination

Question 6

What type of vaccination is the varicella zoster vaccine?

Answer 6

Live attenuated

Question 7

When should VZIG be given?

Answer 7

Within 10 days of significant exposure in a patient that has not had chickenpox

Question 8

When should VZIG not be given?

Answer 8

When a chickenpox rash is present

Question 9

When should acyclovir be given to treat chickenpox in pregnancy?

Answer 9

Within 24 hours of a rash and after 20 weeks gestation

Question 10

How long is a pregnant patient with chickenpox infectious for?

Answer 10

8-28 days (if they received VZIG)

8-21 days (if they did not receive VZIG)

Question 11

What is the incubation period for Varicella Zoster?

Answer 11

14 days (10-21)

Question 12

Which viruses are part of the herpes family?

Answer 12

Varicella zoster, herpes simplex, cytomegalovirus

Question 13

What is the rate of fetal transmission of VZV in the first trimester?

Answer 13

0.4%

Question 14

What is the rate of fetal transmission of VSV in the second trimester?

Answer 14

2%

Question 15

What is the rate of transmission after 20 weeks?

Answer 15

0%

Question 16

What are the maternal consequences of varicella zoster infection?

Answer 16

High risk of pneumonitis (10%)

Hepatitis, encephalitis

Question 17

How do fetal transmission rates for CMV throughout pregnancy?

Answer 17

Fetal transmission rates increase

Question 18

How does gestation affect the risk of CMV infection affecting the neonate?

Answer 18

The risk of a fetus being affected decreases with gestation

Question 19

What are the ultrasound findings of a CMV infected fetus?

Answer 19

IUGR, microcephaly, ventriculomegaly, ascites, hydrops, intracerebral calcifications, echogenic bowel

Question 20

How many affected babies with CMV will be symptomatic at birth?

Answer 20

7-10%

Question 21

What are the clinical features of congenital CMV at birth?

Answer 21

Microcephaly, jaundice, SGA, petechiae, hepatosplenomegaly, jaundice, seizures, visual impairment, cerebral palsy

Question 22

What proportion of babies with congenital CMV are asymptomatic at birth?

Answer 22

approximately 90% (approx. 10% will develop symptoms in later life)

Question 23

What are the clinical features of late stage congenital CMV?

Answer 23

Sensorineural deafness and mental retardation (10%), failure to thrive, failure to reach milestones

Question 24

How is CMV transmitted?

Answer 24

Body fluids (including breast milk)

Question 25

Who is most at risk of developing a CMV infection?

Answer 25

Nursery workers, pregnancy women with nursery age children, teenage pregnant women

Question 26

Can you develop immunity to CMV

Answer 26

No

Question 27

What types of CMV infections are there?

Answer 27

Primary (first infection) vs. non-primary (reactivation or new infection on previously infected)

Question 28

What is the risk of fetal transmission in a primary infection?

Answer 28

40%

Question 29

What is the risk of fetal transmission in a secondary infection?

Answer 29

1%

Question 30

Why is IgG avidity used in CMV testing in pregnancy?

Answer 30

It tells how tightly the IgG binds to the antigen, higher avidity increases the likelihood that the infection is a non-primary infection and therefore is at lower risk of being transmitted to fetus

Question 31

What does negative IgM and IgG for CMV mean?

Answer 31

No active or previous CMV infection

Question 32

What does positive IgM and IgG for CMV mean?

Answer 32

May be either a primary or non-primary infection therefore IgG avidity needs to be performed.

Question 33

What is the incubation period for CMV?

Answer 33

3-12 weeks

Question 34

What are the maternal symptoms of CMV in pregnancy?

Answer 34

Most women are asymptomatic. May be flu like symptoms, general malaise or lethargy

Question 35

When should amniocentesis be performed for CMV?

Answer 35

At least 6 weeks after maternal infection, more than 21 weeks (baby needs to be producing urine)

Question 36

Is there a treatment for CMV?

Answer 36

No

Question 37

What is a retrovirus (+example)?

Answer 37

HIV - RNA virus that uses host DNA for replication

Question 38

What type of virus is rubella?

Answer 38

A togavirus, single stranded RNA. Family = rubibvirus

Question 39

What kind of vaccine is the rubella vaccine?

Answer 39

Live attenuated

Question 40

Incubation period for Rubella

Answer 40

12-23days

Question 41

What are the symptoms of rubella?

Answer 41

25% asymptomatic Joint pain Fever, malaise coryzal symptoms Maculopapular all body rash

Question 42

What are the features of congenital rubella syndrome

Answer 42

80% sensorineural deafness 60% neurological deficit (neurodevelopmental delay, microcephaly) 60% cardiac defect 30% eye defect - cataracts, glaucoma

Question 43

What is the significance of gestation with rubella syndrome infection?

Answer 43

In first trimester - High risk of mortality and morbidity 20% miscarry, 80% affected by the disease In second trimester - 15-20% sensorineural deafness In third trimester - low risk of impact to baby

Question 44

What does Gardasil vaccinate against?

Answer 44

4 Human Papilloma viruses 16 and 18 - responsible for 70% of cervical cancer 6 and 11 - cause anogenital warts

Question 45

What type of virus is HIV?

Answer 45

A retrovirus, Family = lentivirus, single stranded RNA

Question 46

What type of virus is polio

Answer 46

Enterovirus, single stranded RNA virus

Question 47

What type of virus is the zika virus?

Answer 47

Flavirus, single stranded RNA virus

Question 48

Which organism causes scarlet fever?

Answer 48

Streptococcus pyogenes

Question 49

What percentage of women develop antibodies to HPV infection?

Answer 49

50-60%