Varicella-Zoster Virus (VZV) IgM Enzyme-Linked Immunosorbent Assay (ELISA) is intended for the detection of IgM antibody to Varicella-Zoster virus in human serum as an aid in the diagnosis of primary infection or reactivation.
Varicella, more commonly known as chickenpox, and herpes zoster are known clinical manifestations of infection with varicella-zoster virus (VZV). Chicken pox, the clinical syndrome usually produced as a result of the primary infection with VZV, is a highly contagious disease characterized by widely spread vesicular eruptions and fever. The disease is endemic in the U.S. and most commonly affects children from five to eight years of age, although adults and younger children, including infants, may develop chickenpox. Every two to five years, usually in the winter or spring, the number of cases increases to epidemic levels. VZV infection during early pregnancy has been implicated in congenital anomalies in rare cases. When infection occurs at term, life-threatening infections can occur in the neonate.
Herpes zoster is mainly a disease of adults, with most cases appearing in patients fifty years or older. Evidence suggests that this manifestation of VZV infections results from a reactivation of virus which has remained latent in the sensory spinal ganglia after the primary infection rather than a reintroduction of the virus into the host. Fever and painful localized vesicular eruptions of the skin along the distribution of the involved nerves are the most common clinical symptoms of the condition. Zoster lesions can be mistaken for the similar lesions produced by herpes simplex virus in which recurrences are common. However, recurrences of herpes zoster are extremely rare. Determination of the immune status of high risk individuals who are exposed to VZV, the screening for potential donors of Varicella-zoster immunoglobulin, and the diagnosis of VZV infected individuals (both pre- and postnatal) is usually accomplished by serological testing. However, some serological studies suggest that reinfection or reactivation of VZV may occur in the absence of clinical symptoms.
The various methods of serodiagnositic tests for the detection of VZV antibodies in a patient's serum include indirect immunofluorescence, neutralization, complement fixation and fluorescent antibody to membrane antigen (FAMA). FAMA is generally considered the most sensitive and specific of the methods, yet requires the use of cell culture which is cumbersome to perform. Clinical and correlation studies performed by Shehab and Brunell indicate that the ELISA methodology may be as sensitive and perhaps more specific than the FAMA assay. The sensitivity, specificity, and reproducibility of enzyme-linked immunoassays is comparable to other serological tests for antibody, such as immunofluorescence, complement fixation, hemagglutination and radioimmunoassays.