Studies on a Virus Isolated from a Severe Case of Epidemic Hepatitis; A Probable Causative Agent of Epidemic Hepatitis.

Abstract

An emulsion of liver from a severe case of epidemic hepatitis or subacute liver atrophy was inoculated as usually intraperitoneally into young mice. The essential results may be summarized as follows.
1) The mice of the first generation died in most cases 12-21 days after inoculation. The mice of the following generation died mostly 3-10 days after inoculation.In ninety-four days (from Feb. 5 to May 8) successive inoculations were continued and twenty generations have passed. Each generation of shorter duration consists of five days in average.
2) In this experimental period there has been observed no sign of attenuation.
3) The virulence of the strain is well preserved in an usual way.
4) The liver and the spleen of the infected mice are enlarged.
5) The histopathological findings of the livers of mice show the typical fulminant hepatitis.
6) Electronic microscopic photographs revealed numerous almost uniform round particles. The particles are 100-150mμ large.
7) The virulence of this strain was neutralized with a serum of a reconvalescent of epidemic hepatitis.
8) This strain may be a probable causative agent of epidemic hepatitis.