Experimental Herpetic Encephalitis in the Guinea Pig Produced Through the Respiratory Tract.

Abstract

In a previous communication 1 we described experimental herpetic encephalitis produced by feeding herpes virus to guinea pigs. The brains from such animals, dying after feeding of herpes virus, when injected into rabbits by the intraspinous route produced typical herpetic encephalitis and the disease could be passed in series from rabbit to rabbit. Control cultures of the guinea pig brains were without growth. It was noted that the herpes virus was somewhat attenuated following passage through guinea pigs by this method but its virulence rapidly returned by rabbit passage. It was further observed that only about 50% of the guinea pigs so treated with herpes virus died, the others remaining apparently unaffected. The “Beckley” strain of herpes (Flexner) was used in these experiments.

The apparent passage of the herpes virus from the intestine of the guinea pig to the brain, as demonstrated by subsequent passage through rabbits, has led us to consider the possibility of infecting guinea pigs by dropping herpetic brain emulsion into the nostrils of these animals.∗ In these experiments we have employed the Le Fèvre herpes strain which has been fully described in another publication. 2

An emulsion of herpetic (Le Fèvre) rabbit brain was prepared by emulsifying one gm. of infected brain in 5 cc. of physiologic salt solution. In the first experiment 3 guinea pigs were given 10 drops of this emulsion in each nostril. Three control guinea pigs received a similar quantity of an emulsion prepared with normal rabbit brain. Seven days after treatment one of the guinea pigs became ill and on the eighth day was in coma and had repeated convulsions. The animal remained in this state for 30 hours and was sacrificed late on the ninth day.