Western blot assay for detecting IgG antibodies in patient and rodent blood samples. A 1:500 dilution of serum was used to probe Western blots containing equimolar amounts of recombinant-expressed N antigens of various hantaviruses: 1) Bayou; 2) Muleshoe; 3) Puumala; 4) Rio Mamoré; 5) Seoul; and 6) Sin Nombre. Serum samples are directed against specific hantaviruses as verified by reverse transcription-PCR and sequence analyses: (A) patient T/Tx, Bayou virus; (B) Bayou virus-seropositive Oryzomy