Parvovirus – Serology

Consistent with O. Reg. 671/92 of the French Language Services Act, laboratory testing information on this page is only available in English because it is scientific or technical in nature and is for use only by qualified health care providers and not by members of the public.

This page provides serological testing information for Parvovirus B19 at Public Health Ontario (PHO). The causative agent(s) of fifth disease or erythema infectiosum (also referred to as “slapped cheek syndrome”).

This page is for information specific to Parvovirus B19 serology.

*Uncontrolled print copy. Valid only on day of print: 11 July 2025.

Testing Indications

To determine acute/recent infection.
During pregnancy in suspected cases of hydrops fetalis.
To assess immune status following exposure to a known active case or during an outbreak investigation.
During investigation of patients with aplastic crisis.
During investigation of patients (particularly women) with acute joint pain and swelling. affecting multiple joints (i.e., polyarthropathy).
As required for public health purposes (e.g., outbreak investigation).

Specimen Collection and Handling

Specimen Requirements

Test Requested	Required Requisition(s)	Specimen Type	Minimum Volume	Collection Kit
Parvovirus IgG Parvovirus IgM	General Test Requisition	Blood or serum	5.0 ml blood or 1.0 ml serum	Blood, clotted - vacutainer tubes (SST)

Submission and Collection Notes

Complete all fields of the requisition form, including:

test(s) requests and indications for testing
patient setting/population/source
specimen type and source
outbreak or investigation number
clinical information (acute/recent infection, vaccination history, relevant signs, symptoms, and/or clinical history, and onset date).

For clinical specimens, label the specimen container(s) with the patient’s first and last name, date of collection, and one other unique identifier such as the patient’s date of birth or Health Card Number. For additional information see: Criteria for Acceptance of Patient Specimens. Failure to provide this information may result in rejection or testing delay.

Parvovirus IgG will be performed on all requests for Parvovirus B19 serology.

Parvovirus IgG and IgM testing will be performed on diagnostic requests only when clinical information is provided on the General Test Requisition Form.

Timing of Specimen Collection

In suspected acute infection, IgM antibodies are detected 10-12 days after infection, and IgG antibodies are detected at 2 weeks. Ninety percent of patients with classic erythema infectiosum rash have IgM antibodies detected at initial presentation and IgG antibodies by day 7. IgM remains detectable for 2 to 4 months and IgG for life following recovery from acute infection.

In pregnant women exposed to parvovirus B19, obtain IgG and IgM serology as soon as possible following exposure. Negative IgG and IgM results indicate that the mother is not immune and that there is no serologic evidence of acute or past infection. In this case, repeat serologic tests in 3 weeks.

In patients with clinically significant anemia, transient aplastic crisis, and parvovirus-associated arthropathy, IgM antibodies are usually present by day 3 of illness.

Limitations

Grossly haemolysed or lipemic samples as well as samples containing particulate matter or exhibiting obvious microbial contamination are not recommended for testing.

Storage and Transport

Specimens should be stored at 2-8°C following collection and shipped to PHO’s laboratory on ice packs. Centrifuge if using serum separator tubes (SST). Place the specimen in a biohazard bag and seal. All clinical specimens must be shipped in accordance to the Transportation of Dangerous Good Act.

Requisitions and Kit Ordering

Test Frequency and Turnaround Time (TAT)

Parvovirus serology to detect Parvovirus IgG and IgM is performed daily Monday to Saturday.

Turnaround time is up to 5 days from receipt by PHO's laboratory.

Test Methods

The Parvovirus testing is performed using the Biotrin Parvovirus B19 assay. The test uses chemiluminescence immunoassay (CLIA) technology for the qualitative determination of specific IgG and IgM antibodies to Parvovirus B19 in human serum samples.

Interpretation

The following table provides possible test results with associated interpretations:

Result	Interpretation	Comments
Positive IgG and Negative IgM	Parvovirus IgG antibodies detected.	Results should be interpreted in the context of the clinical history, signs and symptoms of the patient.
Positive IgG and IgM	Possible recent or acute Parvovirus B19 infection.	Results should be interpreted in the context of the clinical history, signs and symptoms of the patient.
Negative IgG and Positive IgM	Possible recent or acute Parvovirus B19 infection, OR non-specific IgM reactivity.	Results should be interpreted in the context of the clinical history, signs and symptoms of the patient.
Negative IgG and IgM	No serological evidence of recent or past Parvovirus B19 infection.	Results should be interpreted in the context of the clinical history, signs and symptoms of the patient.

Reporting

Results are reported to the physician, authorized health care provider (General O. Reg 45/22, s.18) or submitter as indicated on the requisition.