FIG. 4.

The mean OD values for rates of reaction to heterologous antigens (y axis). (a) Patterns of cross-reactions of hantavirus-positive human sera to heteroantigens. (b) Patterns of cross-reactions of hantavirus-positive rodent sera to heteroantigens. The mean OD value for rates of reaction of serum specimens to heterologous antigens was 37.9%, with an SD of 22.9% for those to homologous antigens. Therefore, as the mean of the rates of reaction for homologous and heterologous antigens plus twice the SD of the OD values was 83.7%, the cutoff value to distinguish homologous and heterologous reactions was tentatively determined to be 80%. The dotted lines indicate the cutoff value to identify the serotype. *, the numbers indicate the number of serotyped samples (left) and the total number of samples (right).