Host metabolic alterations during Venezuelan equine encephalitis in the rat

Although an effective vaccine exists to protect against VEE, not all persons who may be exposed to this disease are likely to be vaccinated. The disease most often presents as a short febrile illness but the convalescence period may be protracted, and death due to encephalitis does occur in a small percentage of those infected. Knowledge of the metabolic alterations which occur during VEE may materially aid in its treatment. Use of the V-198 strain of VEE in the rat produces a uniform model in which to study metabolic alterations. Changes that occur early in the disease include viremia, neutrophilia, a decrease in plasma zinc and transferrin, and increased amino acid uptake into liver. Plasma zinc depression persists into the later stage of the disease, but to a lesser degree. Increases in plasma copper and seromucoid occur late in the disease, concurrent with the development of pronounced encephalitis. Hypoalbuminemia and decreased ketonemia occur during both the early and late stages of the disease. Taken together, these metabolic alterations appear to chronicle the development of VEE in the rat. If these metabolic alterations can be linked to specific pathogenic processes, they may be useful as prognostic indicators, in formulating supportive therapy, and as monitors of potential antiviral therapy.