| Abstract: | Preparations of formalin-treated erythrocytes sensitized with meningococcus polysaccharides of serological groups A, C, X, Y, and Z were used for the purpose of examination of patients with meningococcus infection; these preparations were highly specific in the tests of precipitation, hemagglutination and hemagglutination inhibition. Indirect hemagglutination test with the sera of 99 patients suffering from generalized forms of meningococcus infection was conducted with the mentioned preparations in Moscow and Novosibirsk in 1974--1975 when a stable morbidity decline was noted in these towns after an epidemic rise. The diagnostic value of this test was confirmed: it permitted to diagnose meningococcus etiology beginning from the 5th day of the disease and to decipher it from the aspect of individual serological groups. As shown, the incidence of cases caused by serological group A, reaching 87% at the height of the epidemic rise, fell to 49.5% at the stage of decline. Cases caused by group Y which was not encountered formerly were revealed in 16.2% of the patients. Among 127 patients with miningitis of nonmeningococcus etiology meningococcus antibodies to groups A and Y were revealed with the same frequency (in titres of not over 1 : 20--1 : 80), but the leading role of serological group A in the etiology of the manifest forms permitted to draw a conclusion on the presence of a higher invasiveness in the strains of group A. |
