Early and late pathologic changes in the adrenal glands of mice after infection with herpes simplex virus type 1.

Intranasal infection of CH/HeN mice with herpes simplex virus Type 1 (HSV-1), VR3 strain, caused a high death rate in the 3-12 days following inoculation. Acute interstitial pneumonia and focal adrenal necrosis developed in almost all the animals. About 20% of the mice showed meningoencephalitis and myocarditis. Viral antigen was demonstrated by immunoperoxidase staining in the alveolar walls, around bronchi and blood vessels, and in focal areas of the adrenal cortex as early as 24-48 hours after infection. The virus disseminated probably hematogenously from the lungs and seemed to localize preferentially in the adrenals. In mice surviving the acute stage of infection a subcapsular cell reaction developed in the adrenal cortex. The extensive pneumonia and adrenal necrosis contributed to the high mortality rate of weanling mice infected with HSV-1. The route of viral inoculation and the age of the host animal seemed to influence the localization and outcome of the pathologic process.