Heterophile agglutinin and cold autohemagglutinin titers were determined in 123 cases of schistosomiasis, 104 cases of filariasis, 40 untreated cases of malaria, and 18 cases of leprosy. In schistosomiasis, 4.9% had heterophile agglutinin titers over 1:32, in filariasis 13% had titers above 1:32, and of the malaria cases 5% had titers above 1:32; in no case was the titer higher than 1:128. In the small group of blood specimens from lepers, four showed a heterophile agglutinin titer of 1:128. Of twelve quinine-treated malaria cases, nine had a titer of 1:32 or lower, and three, a titer of 1:64.
Of the above group of 285 blood specimens, cold autohemagglutinins in a titer of 1:10 or higher could not be demonstrated in 279 or 97%. The few positive specimens showed no particular distribution and the highest titer noted was 1:80.