Relationship of Agents of Trachoma and Inclusion Conjunctivitis to Those of Lymphogranuloma-Psittacosis Group

Abstract

While the nature of the etiologic agents of trachoma and inclusion blennorrhea is still not indisputably established, they appear to belong to the group of agents generally known as viruses and the great preponderance of evidence points to a causal relationship for the elementary and initial bodies which are characteristically present in the lesions. 1

That these elementary and initial bodies, and other related structures are similar in morphology and dimension to those found in psittacosis and lymphogranuloma venereum has been pointed out.^{2, 3} Moreover, with the exception of the glycogen reaction, which is positive for the large plaques in trachoma and inclusion blennorrhea, 4 but negative for those in psittacosis and lymphogranuloma venereum, 3 the tinctorial characteristics of the morphological units in all 4 diseases are similar.

A further bond between the two groups lies in the fact that of all the so-called virus diseases only 4, namely trachoma, inclusion blennorrhea, lymphogranuloma venereum, pneumonitis of mice, 5 together with the rickettsial infection of heart-water in sheep, 6 are known to respond to chemotherapy with the sulfonamide drugs.

It has recently been demonstrated that a powerful complement fixing antigen can be prepared for lymphogranuloma venereum by the propagation of the agent of this disease in the yolk-sac of the embryonated chick egg. 7 Furthermore, it has been shown that this antigen gives marked cross fixation with sera from individuals infected with other members of this group of agents, i. e., psittacosis or pneumonitis. 8 It seemed of interest, therefore, to test the sera of individuals infected with trachoma or inclusion blennorrhea by the same method to see whether any cross-fixation would occur here.

The results are shown in Table I. It was found that in the case of adults suffering from chronic trachoma (Institution EI) our usual routine of fixation at 37 C for 1 ½ hours gave fixation at serum titers comparable to those obtained with some lymphogranulomatous sera.