To develop a rapid antibody test for Sin Nombre hantavirus (SNV)
infection for diagnosis of
hantavirus pulmonary syndrome (HPS) in field settings where advanced instrumentation is not available, a strip immunoblot assay bearing four immobilized
antigens for SNV and a recombinant
nucleocapsid protein antigen of Seoul hantavirus (SEOV) was prepared. The SNV
antigens included a full-length recombinant-expressed nucleocapsid (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 55 to 88). On the basis of the observed reactivities of hantavirus-infected patient and control sera, we determined that a positive assay requires reactivity with SNV or SEOV rN
antigen and at least one other
antigen. Isolated reactivity to either viral rN
antigen is indeterminate, and any pattern of reactivity that does not include reactivity to an rN
antigen is considered indeterminate but is unlikely to represent
hantavirus infection. Fifty-eight of 59 samples from patients with acute SNV-associated HPS were positive according to these criteria, and one was initially indeterminate. Four of four samples from patients with HPS due to other hantaviruses were positive, as were most samples from patients with SEOV and Puumala virus
infections. Of 192 control serum samples, 2 (1%) were positive and 2 were indeterminate. Acute SNV
infection was distinguishable from remote SNV
infection or
infection with hantaviruses other than SNV by the presence of G1
peptide antigen reactivities in the former. The strip immunoblot assay shows promise for the detection of SNV
antibodies early in the course of HPS.