In the utilization of antipneumococcus serum in the treatment of pneumonia in infants and in children it is essential that early and rapid typing of the pneumococcus be made. The commonly used methods have been somewhat unsatisfactory. After the modification of the Neufeld reaction was described for rapid determination of the type of pneumococcus in the sputum of adults by Armstrong1 and Logan and Smeall2 in 1932 and somewhat further modified by Sabin in 1933,3 we sought to modify the procedure in order to adapt it for typing of pneumococci in laryngeal swabs obtained from children.
In the older methods of typing pneumococci from children, considerable time was required. This was mainly due to a lack of suitable material, since children swallow their sputum. Pharyngeal or laryngeal swabs were therefore used. Such specimens contained relatively few pneumococci, and often the many contaminating organisms present overgrew them.