INVESTIGATIONS OF MENINGOCOCCAL INFECTION. II. IMMUNOLOGICAL ASPECTS 1

Abstract

Several methods have been employed for the demonstration of specific antibody in the sera of patients with meningoceccal meningitis and in the sera of carriers and contacts. An increase in the titer of agglutinins during the course of the disease could be demonstrated in patients'' acute and convalescent sera. Agglutinins were shown to appear as early as the 7th day and to persist as long as the 28th day. Relatively high agglutinin titers were demonstrated in the sera of 4 carriers of Group I organisms. Of 59 normal Group I contacts, 40 had titers of 1:8 or lower; 11 of the 19 contacts with higher titers were found to be concentrated in 2 households. The mouse-protection test was found to be impractical for use with sera from patients who had received sulfonamide therapy because of the protective action of small amts. of drug and the difficulty in inhibiting this action with para-aminobenzoic acid. Quellung was produced by 6 convalescent sera from Group I cases when the organisms were incubated in the serum for from 2 to 4 hours. The complement-fixation test was positive in the majority of the convalescent sera from Group I cases. The plate precipitin test was negative. The results of bactericidal tests depended both on the properties of the strain of meningococcus employed and on the presence of antibodies in the sera.