THE EFFECT OF UNDERNOURISHMENT ON THE SUSCEPTIBILITY OF THE RABBIT TO INFECTION WITH VACCINIA.

Experiments are reported in which it is shown that if rabbits are deprived of food, the lesions resulting from injection of vaccinia are either fewer or smaller; presumably this is partially explainable on reduction of available nutrients in the cell. The number and character of the lesions are also modified by the state of hydration of the interstitial tissues: If the amount of interstitial fluid is increased by permitting the animal to drink water, the lesions are even less numerous; but if the interstitial tissues are dehydrated either by withholding water or by injecting physiological saline solution into the peritoneal cavity, then the lesions are more numerous. The increase in interstitial fluids in these experiments was not due to decreased plasma proteins, for these were normal. In this respect, therefore, the rabbit differs from man, for unless the plasma proteins are reduced, simple starvation in man results in dehydration rather than edema of the tissues. From these experiments it is concluded that the virus is less able to multiply in the poorly nourished cell than in the well nourished one, and that hydration of the tissues increases the resistance of the tissue to infection while dehydration has the opposite effect. It is suggested that this is because hydration tends to localize the virus in situ, with result that fewer cells are exposed to it, while dehydration has the opposite effect. However, actual changes in cell susceptibility consequent upon altered water balance may be responsible for the effect.