Abstract
Between epidemy of C. R. -positive P. A. P. and agglutinin value of healthy people in the same district a sort of relationship can be found.
On the beginning of the epidemy, remarkable high value cases can be found, but not on prolonged epidemy.
On the beginning of epidemy, along the alteration of it, positivity and negativity of C. R. of healthy people seems to be inverse each other. But, by prolonged epidemy, if positivity is relative low, negativity is also low. And, till at least 2∼3 years after epidemy, negativity seems to remain low.
By these facts, we believe to be able to inspect an epidemiological condition of P. A. P. of a district through C. R. results of so called healthy but latent infected people in the same district.
