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HelpTest Code PARVO Parvovirus B19, Molecular Detection, PCR, Varies
Reporting Name
Parvovirus B19 PCRUseful For
Diagnosing parvovirus B19 infection
Method Name
Real-Time Polymerase Chain Reaction (PCR)/DNA Probe Hybridization
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
VariesNecessary Information
Specimen source is required.
Specimen Required
Submit only 1 of the following specimens:
Preferred:
Specimen Type: Amniotic fluid
Container/Tube: Amniotic fluid container
Specimen Volume: 0.5 mL
Collection Instructions:
1. Do not centrifuge.
2. Label specimen as amniotic fluid.
Specimen Type: Spinal fluid
Container/Tube: Sterile vial
Specimen Volume: 0.5 mL
Collection Instructions:
1. Do not centrifuge.
2. Label specimen as spinal fluid.
Specimen Type: Synovial fluid
Container/Tube: Sterile vial or lavender top (EDTA)
Specimen Volume: 0.5 mL
Collection Instructions: Label specimen as synovial fluid.
Alternate:
Specimen Type: Bone marrow
Container/Tube: Sterile container or lavender top (EDTA)
Specimen Volume: 0.5 mL
Collection Instructions: Label specimen as bone marrow.
Specimen Minimum Volume
Amniotic Fluid, Bone Marrow, and Spinal Fluid 0.3 mL; Synovial fluid 0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Refrigerated (preferred) | 7 days | |
| Frozen | 7 days |
Reject Due To
| All specimens will be evaluated at Mayo Clinic Laboratories for test suitability. |
Reference Values
Negative
Day(s) Performed
Monday through Friday
CPT Code Information
87798
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| PARVO | Parvovirus B19 PCR | 9571-1 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| SRC73 | Source | 31208-2 |
| 83151 | Parvovirus B19 By Rapid PCR | 9571-1 |
Clinical Information
Parvovirus B19 is a DNA virus that preferentially replicates in erythroid progenitor cells.(1) Infection with parvovirus B19 can occur at any age, but is most common early in life. Antibody prevalence ranges from 2% to 15% in children 1 to 5 years old to 30% to 60% in adults.(1) The virus is transmitted by respiratory secretions and occasionally by blood products.
Parvovirus B19 infections can be asymptomatic or produce a wide spectrum of disease ranging from erythema infectiosum (“fifth disease" characterized by a classic “slapped cheek" rash) in children to arthropathy, severe anemia, and systemic manifestations involving the central nervous system, heart, and liver depending on the immune competence of the host.(2,3) Infection with parvovirus B19 in pregnant women may cause hydrops fetalis, congenital anemia, spontaneous abortion, or stillbirth of the fetus.(4) Parvovirus B19 is also the causative agent of transient aplastic crisis and chronic aplasia usually, but not exclusively, in immunocompromised or transplant patients, and those with preexisting hematologic disorders (eg, sickle cell disease).
Most acute infections with parvovirus B19 are diagnosed in the laboratory by serologically detecting IgG- and IgM-class antibodies with enzyme-linked immunosorbent assay testing.
Interpretation
A positive result indicates that parvovirus B19 DNA is present in the clinical sample. However, a positive result does not differentiate between actively replicating virus, transient infection that may be asymptomatic, or the presence of remnant viral nucleic acid.
A negative result suggests the absence of parvovirus B19 infection.
Cautions
A negative result does not necessarily indicate the absence of parvovirus B19 infection. False-negative results may be due to the virus being present at levels below the limit of detection for this assay, or to inhibitory substances that may be present in the specimen.
This assay has only been validated for the detection of genotype 1 parvovirus B19 and its ability to detect the less common genotypes 2 and 3 is unknown.
Method Description
Viral DNA is extracted from 0.2 mL of specimen by the MagNA Pure automated instrument (Roche Applied Science). LightCycler polymerase chain reaction (PCR) primers and probes detect target B19 DNA (nonstructural protein). The LightCycler instrument amplifies and monitors by fluorescence the development of target nucleic acid sequences after the annealing step during PCR cycling. This automated PCR system can rapidly detect (30-40 minutes) amplicon development through stringent air-controlled temperature cycling in capillary cuvettes. The detection of amplified products is based on the fluorescence resonance energy transfer (FRET) principle. For FRET product detection, a hybridization probe with a donor fluorophore, fluorescein, on the 3' end is excited by an external light source and emits light that is absorbed by a second hybridization probe with an acceptor fluorophore, LC-Red 640, at the 5' end. The acceptor fluorophore then emits a light of a different wavelength that can be measured with a signal that is proportional to the amount of specific PCR product. Melting curve analysis is performed following PCR amplification. Starting at 45° C, the temperature in the thermal chamber is slowly raised to 80° C and the fluorescence is measured at frequent intervals. Analysis of the PCR amplification and the probe melting curves is accomplished through the use of LightCycler software.(Soares RM, Durigon El, Bersano JG, Richtzenhain LG: Detection of porcine parvovirus DNA by the polymerase chain reaction assay using primers to the highly conserved nonstructural protein gene, NS-1. J Virol Methods. 1999 Mar;78(1-2):191-198)