Fetal infection of the baboon (Papio cynocephalus) with lymphocytic choriomeningitis virus.

Recent observations of LCM-induced fetal damage in humans suggested attempts to develop an animal model for studies on viral congenital malformations. We report herein viral studies on three pregnant baboons (Papio cynocephalus) inoculated subcutaneously with LCM virus strain WE3. The first animal, inoculated in the 9th week of pregnancy, aborted 9 days after a high virus dose. Inoculation of the second baboon during a later stage (23rd week) of pregnancy with a moderate virus dose, resulted in the demonstration of virus in the placenta, amniotic fluid, and cord blood. The infant showed only a slight pleocytosis of the spinal fluid, but no virus shedding and no late sequelae. The third baboon inoculated with a high virus dose during the 21st week of pregnancy delivered an underweight, icteric infant that succumbed on the 6th day. All organs of this animal that were tested contained virus. Microscopic examination of these tissues revealed multifocal necrosis, cerebral glial nodules, meningitis, and bilateral choriovasculitis. These results illustrate that fetal damage observed in the LCM-inoculate baboon resembles that seen in humans following infection with LCM virus.