PNEUMOCOCCUS TYPE II AND TYPE V INFECTIONS

The separation of types among the pneumococci previously included in group IV¹ has made it possible properly to classify pneumococci from practically all sources,² thus affording a more rational attack on various epidemiologic,³ immunologic⁴ and clinical⁵ aspects of pneumococcic infections and their specific treatment.⁶ It has made possible also the segregation of pneumococci previously recognized primarily because of their relationship to other types.⁷ The antibody response to infections with such related types and the immunologic reactions of normal human subjects to these pneumococci have already received some attention.⁸ The clinical and bacteriologic features of the disease produced by type III and the related type VIII pneumococci have been reported from two different clinics.⁹ This paper deals with the more important features of infections with type II and the related type V pneumococci, with especial reference to pneumonia.

The type II pneumococcus ranks second or third in frequency as a