INTERSTITIAL ORCHITIS WITH IMPAIRED STEROIDOGENESIS AND SPERMATOGENESIS IN THE TESTES OF RABBITS INFECTED WITH AN ATTENUATED STRAIN OF MYXOMA VIRUS

The pathogenesis of infertility associated with acute viral orchitis w as investigated in a rabbit model. Infection of postpubertal male Euro pean rabbits with an attenuated strain of myxoma virus caused systemic disease with viral replication to high titres in the testes. Infected rabbits developed an interstitial orchitis and epididymitis. This was associated with degeneration of the seminiferous epithelium, decrease d serum testosterone concentrations and increased serum LH concentrati ons. Virus was localized within the interstitial cells. Clearance of i nfectious virus from the testis occurred between day 20 and day 30 aft er infection, although viral DNA could still be detected by polymerase chain reaction at 120 days. Viral clearance was associated with a ret urn to normal serum testosterone and LH concentrations. Anti-sperm ant ibodies were present in the serum as early as 5 days after infection a nd declined during the recovery phase. Rabbits were infertile at 60 da ys but returned to normal fertility 60-90 days after infection.