Human Scarlatinal Streptococci in Monkeys.

Hemolytic streptococci have been isolated on numerous occasions from spontaneously infected animals, and apparently in some animals they constitute a portion of the normal flora. In 1933, Lancefield demonstrated that the animal strains could be distinguished from those of human origin by means of a precipitin test. This method gave results in accord with those obtained by the already available biochemical and cultural tests. Organisms causing human disease fell into one serological group, group A, while those isolated from animals were found to belong in other groups, notably B and C. Excluding human strains isolated from the udders of cows during epidemics of sore throat and scarlet fever, exceptions to this rule were very rare. Such was the experience of other investigators (Edwards, 1934; Brightman, 1935; Pilot et al., 1936 a and b; Evans, 1936; Coffey, 1937 and 1938). In 1936, Seegal, Heller and Jablonowitz in a study of the pharyngeal flora of normal rhesus monkeys recovered hemolytic streptococci in large numbers from the throats of 28 out of 49 animals. Of these strains, 19 by tests were of the human variety. There was no evidence that these organisms were causing disease in the monkeys. The authors suggest that possibly the monkeys had acquired the organism from human contacts since they had been in captivity for some time, and that the animals in turn