Studies of a "new" rickettsiosis "Astrakhan" spotted fever.

The acute febrile disease with characteristic rash seen in Astrakhan region and named as "viral exanthema of unknown etiology" was proved to be a spotted fever group rickettsiosis. Serological examination of humans from endemic areas by complement fixation test revealed antibodies to R. conorii, R.

[Importance of T-lymphocytes in antibody production in experimental typhus infection].

The study of antibody production in cotton rats infected with Rickettsia prowazekii B and TB has revealed that R. prowazekii antigens, inducing the production of antibodies determined in the complement fixation, indirect hemolysis, and passive hemagglutination tests, are T-independent. The study of the nonspecific reactivity of T-lymphocytes in cotton rats infected with R.

Thymus-independent antibody production to the antigen of Rickettsia prowazekii.

Antibody production has been studied in cotton B-rats and in CBA B-mice during immunization with chemical typhus vaccine (CTV) and during infection with Rickettsia prowazekii. Studies of the immune response to rickettsial antigen in T-deficient animals have shown a high immunogenicity of CTV and independence of antibody production on T-lymphocytes. Active antibody synthesis was also observed in B-rats and B-mice during Rickettsia prowazekii infection.