Efficacy of a recombinant Norwalk virus protein enzyme immunoassay for the diagnosis of infections with Norwalk virus and other human "candidate" caliciviruses.

A recombinant Norwalk virus antigen enzyme immunoassay (rNV EIA) for the detection fo Norwalk virus (NV) antibodies was evaluated using sera from volunteers and patients infected with Norwalk, Hawaii, Snow Mountain Agent, small round structured viruses (SRSV), and human calicivirus (HuCV) strains. The results for NV antibodies correlated well with previous results obtained using a NV radioimmunoassay. The test rNV EIA was found to be highly specific for NV. The results of tests on sera obtained from patients involved in confirmed outbreaks of SRSV in the UK showed that only 1/12 was due to Norwalk virus. Further evidence is presented that SRSV strain UK2 is antigenically related to NV.