positive sera with a low titer in the pa test ( 1/16 , 1/32 and 1/64 ) contained igm antibodies in 32.5 % ( titer 1/16 ) to 36.1 % ( titer 1/64 ) of the cases , but igg antibodies were detected in only 5.6 % of the sera with a titer of 1/16 and in 36.1 % of the sera with a titer of 1/64 .
C0020861
igm antibodies
C0003241
antibodies