DETECTION OF ANTIBODY TO RECOMBINANT NORWALK VIRUS-ANTIGEN IN SPECIMENS FROM OUTBREAKS OF GASTROENTERITIS

Norwalk virus and other small round-structured viruses are commonly as sociated with outbreaks of gastroenteritis. We used a recently describ ed recombinant-expressed Norwalk virus (rNV) capsid protein in enzyme immunoassays to quantitatively measure immunoglobulin G (IgG) and IgA to Norwalk virus in serum pairs from patients involved in outbreaks of gastroenteritis. The outbreaks previously were classified, on the bas is of the results of a blocking antibody assay, as Norwalk virus negat ive, serologically intermediate, or Norwalk virus positive. The rNV Ig G assay was more sensitive than the blocking assay for detecting IgG t o Norwalk virus in serum from patients in all outbreak classes. There was 79% concordance between seroconversions detected by the blocking a ntibody assay and those detected by the rNV IgG assay. The rNV IgA ass ay detected seroconversions to Norwalk virus primarily in patients inv olved in outbreaks previously classified as Norwalk virus positive.