Usefulness of Organ Emulsions of Infected Animals in Diagnosis of Lymphogranuloma Inguinale

To make available a larger supply of L. I.∗ antigen for clinical and laboratory investigations than could be obtained by the method of Frei, 1 and completely to eliminate the possibility of an occasional false positive intradermal reaction with the use of human material for antigen, we have produced experimental meningo-encephalitis in white mice and monkeys with the virus of lymphogranuloma inguinale, after the method of Hellerström 2 and of Levaditi 3 and his coworkers. The diluted sterilized brain emulsions of both white mice and monkeys (marmosets) have consistently given intradermal reactions, comparable to those obtained with antigens prepared from acute L.I. inguinal buboes after the method of Frei.

The original source of the virus is pus from an acute inguinal bubo in a patient with a positive Frei reaction. The excised lymph nodes must present the characteristic histologic changes of L.I. The lymph gland emulsion may be used in the event that little or no free pus is available. With the finely divided sterile suspension of this material in physiological saline, white mice and monkeys are inoculated intracerebrally. For mice, .01–.02 cc. are used, and for monkeys, 0.2–0.3 cc. The animals employed are the white mouse and the common marmoset (Hapale penicillata), which are highly susceptible to infection with the virus of lymphogranuloma inguinale. The mice are killed at the end of one week, their brains being pooled for convenience, but the monkeys are permitted to succumb to diffuse meningo-encephalitis (1 to 2 weeks) or are killed when signs of paralysis develop. Microscopic brain sections show a more or less intense meningeal reaction. Bacteriologic cultures must be consistently negative.