Parvovirus B19

Question 1

Parvovirus B19 clinical disease in children

Answer 1

5th Disease
“Slapped Cheek Syndrome”

Question 2

Parvovirus transmission

Answer 2

1. Respiratory droplets
2. Blood transfusion
3. Vertical transmission

Question 3

Parvovirus method of replication

Answer 3

Erythroid progenitor cells in bone marrow –> replication –> induced apoptosis of cell –> viraemia
Immune response occurs after 10-14 days in immunocompetent

Question 4

Symptoms of Parvovirus

Answer 4

1. Flu-like illness with viraemia (after 4-14 days incubation)
2. Followed by rash + joint pain
3. Transient aplastic crisis in susceptible individuals (e.g. sickle cell, thalassaemia)

Question 5

Risk of infection if susceptible after exposure during epidemic
- at home
- at school / child care
- in community

Answer 5

1. 50%
2. 20-30%
3. 20%

Question 6

Proportion of women of child-bearing age susceptible to parvovirus infection

Answer 6

40%

Question 7

Risk of transmission from infected mother to fetus parvovirus

Answer 7

50%

Question 8

Fetal outcomes of proven maternal infection before 20 weeks’ gestation Parvovirus

Answer 8

1. Fetal loss (10% excess)
2. Hydrops 3% (between 9 and 20 weeks)

Question 9

Outcomes of hydrops in parvovirus B19

Answer 9

1. Spontaneous resolution within 8 weeks (32%)
2. Death without intrauterine transfusion 33%
3. Resolution after IUT 27%
   4 Death after IUT 6%

Question 10

Parvovirus B19 IgM

Answer 10

• Detectable 1-3 weeks after exposure and detectable for 2-3 months
• Can have false positives - repeat in 2-4 weeks if IgM pos but IgG neg