SEROLOGIC STRAIN DIFFERENTIATION IN TRACHOMA

Abstract
An in vitro test for the differentiation of trachoma strain isolates is described. The method is based on absorption of trachoma anti-serum followed by immunofluorescent staining of individual trachoma strains. 19 trachoma strains were studied; two main types were identified. Evidence for quantitative and qualitative antigenic variation between the two types is presented. The limitations in practice and in theory of the test are emphasized.