DEFINITION OF HEMOLYTIC STREPTOCOCCUS PARASITISM IN THE UPPER AIR PASSAGES OF HEALTHY PEOPLE

Abstract

The study of an epidemic or of an outbreak of certain acute infectious diseases can perhaps best be approached from the standpoint of deviation from average or normal conditions. Such a mode of attack seems specially applicable to those infections caused by bacteria which may be harbored by carriers, and which are constantly present, at least to a certain extent, in the community; and the question which presents itself is why the apparent balance between parasite and host becomes upset, with a consequent spread of organisms and production of disease. The problem is tremendously complex and doubtless involves many unknown factors. However, in the recorded studies of epidemics, certain fairly definite alterations in the distribution of the causal bacteria among the general population have been observed; the carrier rate both among healthy contacts and healthy noncontacts almost invariably rises. During epidemics of meningitis, for example, the carrier rate may rise