Comparative evaluation of commercial methods for the detection of parvovirus B19-specific immunoglobulin M

The serological diagnosis of parvovirus B19 (PVB19) was performed by radioimmunoassay or enzyme-linked immunosorbent assay (ELISA), using plasma-derived antigen, in view of the difficulties in obtaining the virus. Since the development of recombinant proteins, a number of commercial kits for detecting both specific immunoglobulin G (IgG) and IgM have become available. We evaluated seven methods, including indirect- and μ-chain-capture ELISA, indirect immunofluorescence and Western blot, in an effort to identify PVB19 IgM. In acute samples of erythema infectiosum, the sensitivity ranged from 37% to 91%; in all samples from primary PVB19 infections, including acute and convalescent samples of erythema infectiosum, and from other primary infections in adults, the sensitivity varied from 31% to 79%. When samples from rubella, measles, infectious mononucleosis and healthy pregnant women were tested, specificity ranged from 67% to 100%. Not all the kits evaluated can be used to diagnose PVB19 infections in view of the limitations of some kits with respect to sensitivity and, more importantly, specificity.