Responses of IgM for enterovirus 71 infection.

A rapid serological assay was developed for detection of specific IgM to enterovirus 71, a human picornavirus that is usually associated with severe central nervous system complications. The sensitivity and specificity of this "in-house" mu-capture enzyme linked-immunosorbent assay was assessed by testing 213 serum samples. With the conventional virus culture as a standard method, the sensitivity and specificity were 91.5 and 93.1%, respectively, for this newly developed immunoassay. This method allows for detection of the IgM responses from the patients either infected by genotype B or genotype C of enterovirus 71. IgM can be detected as early as the second day from the onset of disease. IgM responses exhibit 100% positive rate from enterovirus 71-infected patients with complications, including encephalitis, meningitis, polio-like syndrome, pulmonary edema, and fatal cases. These findings suggest that detection of specific IgM by the use of enzyme linked-immunosorbent assay is a rapid and valuable way for the diagnosis of enterovirus 71 infection.