Parvovirus B19

Parvovirus B19 is a member of the Erythrovirus family, so named because of its tropism for erythroid precursor cells. PCR is more sensitive than antibody testing. Confirmation of parvovirus in pregnancy mandates followup testing of the fetus for the development of hemolytic disease.

Diagnosis

Indications for Testing

  • Rash or arthritis in pregnant females
  • Development of aplastic anemia in immunocompromised patient

Laboratory Testing

  • Antibody testing
    • IgM antibodies
      • Response occurs 7-14 days after onset of disease
      • Remain detectable 2-3 months after infection
    • IgG antibodies
      • IgG elevations ~2-3 weeks after onset
      • IgG antibodies remain detectable for life
    • IgM and IgG antibodies may remain negative in
      • Immunocompromised patients
      • Patients presenting with transient aplastic crisis
    • Retest exposed pregnant females who are initially nonimmune in 3-4 weeks
  • Polymerase chain reaction (PCR) testing
    • More sensitive than antibody testing
    • Serum samples – positive result indicates ongoing acute or persistent infection
    • Bone marrow samples – positive result indicates acute or remote infection
    • Amniotic fluid sample – positive result indicates acute or persistent infection
  • Confirmation of parvovirus infection in pregnancy mandates follow-up testing of fetus for development of hemolytic disease
  • Congenital infection evaluation
    • Maternal IgM testing (7-10 days after infection)
    • PCR testing of mother and amniotic fluid of fetus

Differential Diagnosis

Background

Epidemiology

  • Prevalence
    • 15% of preschool children – seropositive
    • 50% of young adults – seropositive
    • 85% of elderly – seropositive
  • Incidence – peaks in late winter, early spring
  • Age – peak is 5-15 years
  • Transmission
    • Respiratory droplets
    • Blood products
    • Transplacental

Organism

  • Small, single-stranded DNA virus
  • Lacks lipid envelope – resistant to heat and detergent inactivation
  • Targets rapidly growing erythroid progenitor cells

Risk Factors

  • Immunodeficiency disorder
  • Pregnancy

Clinical Presentation

  • Many parvovirus infections are asymptomatic, particularly in children
  • Erythema infectiosum or fifth disease
    • Classically presents in school-age children
    • Benign, self-limited, febrile illness associated with "slapped cheek" appearance on face and lacy or reticular rash on trunk and limbs (sparing of palms and soles)
      • Rash may wax and wane for up to 3 weeks
  • Severe anemia
    • Major complication due to virus's predilection for red cell precursors in bone marrow
    • May cause aplastic crisis or persistent chronic anemia in immunocompromised patients
  • Migratory polyarthropathy
    • May occur in up to 50% of adults, particularly females
    • Generally resolves within a few weeks, but may persist for years (rare)
  • In pregnant females
    • Risk of transplacental infection
    • Risk of fetal loss, primarily if infection occurs in the first trimester and early second trimester
    • Hydrops fetalis – represents 10-20% of all cases of nonimmune hydrops
    • Fetal condition frequently necessitates early delivery
    • ​Severe neonatal anemia, thrombocytopenia, and meningoencephalitis (rare)
  • Associated with onset of autoimmune disorders
  • Transient aplastic crisis
  • Chronic bone marrow failure and pure red cell aplasia (PRCA)
    • May become persistent in patients unable to mount efficient immune response
    • Chronic anemia may result

ARUP Lab Tests

Aid in diagnosis of parvovirus infection

Detect parvovirus B19 in amniotic fluid, blood, cerebrospinal fluid (CSF), tissue, or synovial fluid

Diagnose and monitor human parvovirus infection in patient with suppressed or delayed immune response

Related Tests

Not recommended as a stand-alone test

Panel that combines parvovirus IgG and IgM antibodies is preferred

Medical Experts

Contributor

Couturier

Marc Roger Couturier, PhD, D(ABMM)
Associate Professor of Clinical Pathology, University of Utah
Medical Director, Parasitology/Fecal Testing, Infectious Disease Antigen Testing, Bacteriology, and Molecular Amplified Detection, ARUP Laboratories
Contributor

References

Additional Resources
Resources from the ARUP Institute for Clinical and Experimental Pathology®