A Study of Pneumococcus Carriers

[摘要] The purpose of this study was to determine whether, in Baltimore, the constant carrying of pneumococci in the throat was associated with frequent infections of the upper respiratory tract. Throat cultures were taken from a group of 20 young adults approximately once a week over a period of two academic years. One thousand and sixteen throat cultures were obtained; 34.5 per cent were positive for pneumococci.It seemed, after the first year's study, that individuals could be divided into three groups with respect to the carrying of pneumococci, namely, chronic carriers, intermittent carriers and noncarriers. However, at the end of the second year's study it became apparent that, those individuals who had been classed as intermittent carriers were, in reality, chronic carriers, for, although few positive cultures were obtained from them, and those irregularly, the same type of pneumococcus recurred in their cultures. It was found, during the two years, that there was little difference in the frequency and duration of upper respiratory tract infections between the chronic carriers and the noncarriers.While the same type of pneumococcus tends to recur in the throat cultures from a chronic carrier, it is frequently possible to demonstrate the simultaneous carrying of two or three types of pneumococci in these individuals, if the proper procedures are used. This demonstration is added evidence in favor of the theory of the stability of pneumococcus types in the human being.

[学科分类] 生物科学（综合）