Lab Test

Parvovirus B19 Antibody, IgM

Test Codes



Special Chemistry

Specimen Collection Criteria

Collect: One Gold-top SST tube. (Minimum Whole Blood: 2.0 mL)

Physician Office/Draw Specimen Preparation

Let serum specimen clot 30-60 minutes. Immediately centrifuge to separate serum from cells. Refrigerate (2-8°C or 36-46°F) the centrifuged collection tube within eight hours of collection. (Minimum Serum: 0.5 mL)

Preparation for Courier Transport

Transport: Centrifuged collection tube, refrigerated (2-8°C or 36-46°F). (Minimum Serum: 0.5 mL)

Rejection Criteria

  • Plasma specimens. 
  • Severely hemolyzed, lipemic or icteric specimens. 
  • Specimens not collected and processed as indicated. 

In-Lab Processing

Let serum specimen clot 30-60 minutes. Immediately centrifuge to separate serum from cells. Room temperature (20-26°C or 68-78.8°F) is acceptable for a maximum of eight hours. (Minimum Serum: 0.5 mL)


Specimen Stability for Testing:

Centrifuged SST and Microtainers® with Separator Gel
Room Temperature (20-26°C or 68-78.8°F): 8 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): Unacceptable

Red-top Tubes and Microtainers® without Separator Gel
Room Temperature (20-25°C or 68-77°F): 8 hours
Refrigerated (2-8°C or 36-46°F): Unacceptable
Frozen (-20°C/-4°F or below): Unacceptable

Serum Specimens (Pour-Overs) and Plasma Aliquots
Room Temperature (20-26°C or 68-78.8°F): 8 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): 1 year

Specimen Storage in Department Prior to Disposal:

Refrigerated (2-8°C or 36-46°F): 7 days


Royal Oak Special Testing Laboratory


Tuesday, Thursday.
Results available in 3 business days.

Reference Range

Less than < 0.90 IV
 Negative: No significant level of detectable Parvovirus B19 IgM antibody.
0.9 – 1.10 IV  Equivocal: Repeat testing in 10-14 days may be helpful.
Greater than or equal to 1.11 IV  Positive: IgM antibody to Parvovirus B19 detected which may indicate a current or previous infection.

IV = Index Value.

Index: Optical density (OD) of patient serum divided by the OD of the cutoff value.

Test Methodology

Semi-Quantitative Enzyme-Linked Immunosorbent Assay (ELISA).


Seroconversion between acute and convalescent sera is considered strong evidence of current or recent infection. The best evidence for infection is a significant change on two appropriately timed specimens, where both tests are done in the same laboratory at the same time.

Appearance of an IgM antibody response normally occurs 7-14 days after the onset of disease. Testing immediately post-exposure is of no value without a later convalescent specimen. While the presence of IgM antibodies suggests current or recent infection, low levels of IgM antibodies may occasionally persist for more than 12 months post-infection. Such a residual IgM response may be distinguished from early IgM response to infection by testing sera from patients 3-4 weeks later for changing levels of specific IgM antibodies.

Immunocompromised patients may have a delayed or absent antibody response. Therefore, antibody levels may not be the optimal way to diagnose parvovirus infection in these patients. The best method in these situations is detection of parvovirus DNA in serum.

Clinical Utility

This assay is used in the differential diagnosis of acute and recent from past infection with human parvovirus associated with erythema infectiosum (fifth disease), aplastic crisis, and fetal infection.

Clinical Disease

Erythema infectiosum (EI) or fifth disease is the most common manifestation of human parvovirus infection. EI is an acute, self-limiting febrile illness. Patients with EI are typically healthy except for an erythematous rash on the face (slapped-cheek appearance) and an erythematous reticulated rash on the trunk and extremities. As central clearing occurs, the rash may take on a lace-like appearance. The rash usually resolves within a week. However, the rash may recur intermittently for several weeks, especially after exercise, bathing, thermal changes, or stress. Although most children have few symptoms other than rash, up to 25% of cases may have mild fever, headache, sore throat, and abdominal discomfort. Like most childhood exanthems, human parvovirus infections are somewhat more severe in adults who may experience a moderately severe, self-limited arthropathy of the wrists and knees following human parvovirus infection. Approximately 20% of cases may be asymptomatic.

Complications of B19 infections can be severe or life threatening, especially in patients with chronic hemolytic anemias. These patients require increased red blood cell production in order to maintain stable red cell indices. B19's replication in erythroid precursor cells and the subsequent disruption of RBC production may cause a transient aplastic crisis (TAC) in these patients. In immunodeficient patients, B19 infections can cause severe chronic anemia associated with red cell aplasia.

During pregnancy, B19 infections can (but usually do not) lead to fetal infection. Fetal infection can, in turn, cause severe anemia, congestive heart failure, generalized edema (fetal hydrops), and fetal death. The fetus is vulnerable to severe anemia because it depends upon a high rate of red cell production for growth and development. In addition, its immune system is immature and the fetus may be unable to mount an adequate antibody response. (1)


Human parvovirus occurs most often in the late winter and spring months and epidemics occur at 3-5 year intervals. Erythema infectiosum most commonly occurs in school-aged children aged 5-13 years. Human parvovirus has a worldwide distribution and 60-70% of adults have antibody to the virus. There is only one known serotype. (1)

Incubation Period

The incubation period is 4-14 days but can be as long as 20 days. Patients are infectious during the prodromal period (2-10 days after infection), well before Erythema infectiosum develops. (1)


Human parvovirus is moderately contagious and transmission is presumed to occur through the inhalation of virus-laden droplets. Virus can also be transmitted parenterally by transfusion and vertically from mother to fetus.(1)


  1. Wiedbrauk D, Johnston SLG. Manual of Clinical Virology, Raven Press, New York, NY, 1993.

CPT Codes

LOINC:  5274-6


Last Updated


Microtainer® and Vacutainer® are registered trademarks of Becton, Dickinson and Company.
UroVysion® is a registered trademark of Abbott Laboratories. ThinPrep® is a registered trademark of Hologic, Incorporated.