Genital lesions in experimental chronic Trypanosoma brucei infection in rams.

Rams inoculated intravenously with Trypanosoma brucei developed scrotal oedema and a nonsuppurative granulomatous periorchitis resulting in testicular degeneration, atrophy, calcification and sclerosis. The tunica vaginalis was the seat of an intense granulomatous inflammation and focal necrosis, which extended to the epididymis and spermatic cord. Lesions in the seminal vesicles were suggestive of diminished testosterone production even though Leydig cells were discernible in the sclerotic testicular intertubular tissue. In areas where there was inflammation or focal necrosis, there was also extravascular localisation of trypanosomes. It is suggested that genital lesions in human sleeping sickness may have a similar pathogenetic mechanism involving tissue localisation of the trypanosomes and associated inflammatory and degenerative changes.