The effects of corticosteroids on rabies in mice.

Abstract

Corticosteroid (2–3 mg, 1 mg/day) treatment of mice started within 24 h after rabies virus inoculation increased mortality up to 20% above that in nontreated mice. In contrast, steroid treatment started 48, 72, or 96 h after rabies virus inoculation did not significantly increase mortality. Up to 50% higher mortality occurred in the corticosteroid-treated mice than in the controls after small dosages of rabies virus were injected.In addition to consistently higher mortality, corticosteroid used in conjunction with rabies virus resulted in two changes in the mortality pattern: shortening of the mean incubation period of rabies in mice receiving an LD50 dose, and an aggravation of sublethal infections, causing deaths with abnormally or comparatively long incubation periods in mice that otherwise might have survived. These two actions increased the variability in time of onset and time of death, with an increase in early as well as in late (delayed) onset times.