RAPID AND SPECIFIC DETECTION OF SIN-NOMBRE VIRUS-ANTIBODIES IN PATIENTS WITH HANTAVIRUS PULMONARY SYNDROME BY A STRIP IMMUNOBLOT ASSAY SUITABLE FOR FIELD DIAGNOSIS

To develop a rapid antibody test for Sin Nombre hantavirus (SNV) infec tion for diagnosis of hantavirus pulmonary syndrome (HPS) in field set tings where advanced instrumentation is not available, a strip immunob lot assay bearing four immobilized antigens of SMI and a recombinant n ucleocapsid protein antigen of Seoul hantavirus (SEOV) was prepared. T he SNV antigens included a full-length recombinant-expressed nucleocap sid (N) protein (rN), a recombinant-expressed G1 protein (residues 35 to 117), and synthetic peptides derived from N (residues 17 to 59) and G1 (residues 58 to 88). On the basis of the observed reactivities of hantavirus-infected patient and control sera, we determined that a pos itive assay requires reactivity with SNV or SEOV rN antigen and at lea st one other antigen. Isolated reactivity to either viral rN antigen i s indeterminate, and any pattern of reactivity that does not include r eactivity to an rN antigen is considered indeterminate but is unlikely to represent hantavirus infection. Fifty-eight of 59 samples from pat ients with acute SNV-associated HPS were positive according to these c riteria, and one was initially indeterminate. Four of four samples fro m patients with HPS due to other hantaviruses were positive, as were m ost samples from patients with SEOV and Puumala virus infections. Of 1 92 control serum samples, 2 (1%) were positive and 2 were indeterminat e. Acute SNV infection was distinguishable from remote SNV infection o r infection with hantaviruses other than SNV by the presence of G1 pep tide antigen reactivities in the former. The strip immunoblot assay sh ows promise for the detection of SNV antibodies early in the course of HPS.