Parvovirus B19 Flashcards
Describe parvovirus B19
Single stranded DNA virus
How is parvovirus transmitted?
Droplets or blood
How many women become infected with parvovirus B19 during pregnancy
1 in 400
What proportion of maternal parvovirus B19 infections end up being vertically transmitted to foetus?
A third
What percentage of foetal parvovirus B19 infections end in miscarriage/intrauterine death?
9%
Describe the clinical features of parvovirus B19
Asymptomatic
Symmetrical arthralgia - proximal interphalangeal joints and or knees
Children - URTI, malaise, headache, low grade fever, erythema infectiosum (slapped cheek syndrome - maculopapular rash sparing the nose, eyes and mouth)
What investigations are done when a mother has potentially come into contact with parvovirus B19>
Viral serology
What do parvovirus specivif IgM antibodies mean?
Recent infection
What do parvovirus specific IgG antibodies mena?
Past infection and immunity
Describe maternal management of parvovirus B19
Referal to foetal medicine specialist for further assessment
Self limiting - symptomatic treatment with antipyretics and analgesia
Describe foetal management of parvovirus B19
Serial ultrasounds and doppler assessment - starting 4 weeks post infection or at 16 weeks, repeated every 1-2 weeks until 30 weeks gestation
If evidence of foetal hydrops then refer to tertiary centre for intrauterine erythrocyte transfusion
Describe foetal hydrops
Abnormal fluid accumulation in two or more foetal compartments
How is foetal hydrops diagnosed?
Ultrasound scan -ascites, subcutaenous oedema, pleural effusion, pericardial effusion, scalp oedema and polyhydramnios
How does foetal hydrops occur?
Parvovirus has high affinity for the erythroid system and replicates within erythroid progenitor cells of the liver and bone marrow
Causes severe anaemia
Results in high output cardiac failure and increased extra and intrahepatic erythropoiesis resulting in portal hypertension and hypoproteinaemia with subsequent ascites
