Slapped Cheek disease
This assay may be used to determine serostatus of patients at risk for infection with parvovirus B19.
Results may be used, along with clinical evaluation and additional laboratory findings, to determine recent or past infection status with parvovirus B19.
Specimens collected prior to seroconversion may yield negative IgM or IgG antibody results, while specimens collected after IgM antibody levels have begun to decline may yield negative IgM antibody results. Follow-up testing of convalescent samples may be beneficial to establish infection status.
The continued presence or absence of antibodies cannot be used to determine the success or failure of therapy.
Test results of specimens from immunocompromised patients may be difficult to interpret.
Testing should not be performed as a screening procedure for the general population. Testing should only be done when clinical evidence suggests the diagnosis of parvovirus B19-associated disease.
The performance of this test has not been established on neonates and immunocompromised patients.
Specimens containing antinuclear antibodies may produce equivocal or positive test results in the IgM assay.
Epstein-Barr virus-positive specimens may produce positive or equivocal test results in the IgM assay.
Assay performance characteristics have not been established for matrices other than serum.
Parvovirus B19 is the causative agent of fifth disease (ie, erythema infectiosum, slapped cheek syndrome), which usually produces a mild illness characterized by an intensive erythematous maculopapular facial rash. Most outbreaks of parvovirus infection are acquired by direct contact with respiratory secretions and primarily occur in the spring. Close contact between individuals is responsible for infection in schools, day care centers, and hospitals. The virus has also been associated with fetal damage (hydrops fetalis), aplastic crisis, and arthralgia. Infection during pregnancy presents the risk of transmission to the fetus that may cause intrauterine death. The rate of fetal death following maternal infection ranges between 1% and 9%.
Parvovirus B19 preferentially replicates in erythroid progenitor cells. Infection with parvovirus B19 occurs early in life, and the virus is transmitted by respiratory secretion and occasionally by blood products. The prevalence of parvovirus B19 IgG antibodies increases with age. The age-specific prevalence of antibodies to parvovirus is 2% to 9% of children under 5 years, 15% to 35% in children 5 to 18 years of age, and 30% to 60% in adults (19 years or older).
Most acute infections with parvovirus B19 are diagnosed in the laboratory by serologically detecting IgG and IgM class antibodies to the virus using an enzyme-linked immunosorbent assay testing.