W. P. Havens

Experimental Production of Hepatitis by Feeding Icterogenic Materials.

Summary An experiment on the transmission of infectious hepatitis has been carried out among 19 volunteers at 2 institutions. At one of the institutions 3 different samples of serum containing the icterogenic agent were inoculated intracutaneously into 5 human subjects, and the disease was produced in 3 after incubation periods of 56 to 70 (avg 64) days. At another institution other samples of serum and also specimens of feces (and urine) were fed to 9 human subjects, and the disease was produced in 5 after an incubation period of 20 to 84 (avg 37) days by both of these materials. One case of “naturally acquired” hepatitis has appeared among the institutional personnel 51 days after the beginning of the experiment and 31 days after the appearance of the first experimental case.

Properties of the Etiologic Agent of Infectious Hepatitis.

Summary An experiment on the transmission of the naturally occurring disease, injectious hepatitis, to human volunteers has demonstrated certain properties of the etiologic agent. As in homologous serum jaundice and post-vaccinal jaundice the icterogenic agent of infectious hepatitis is filtrable and withstands heating to 56°C for 30 minutes. The icterogenic agent of infectious hepatitis can be transmit ted in serial passage in human volunteers.

Experiment in Cross Immunity Between Infectious Hepatitis and Homologous Serum Jaundice.

Summary Previous experimental infection (or inoculation without infection) with a strain of homologous serum jaundice obtained in the Middle East failed to protect 5 human volunteers against subsequent experimental infection induced 6 months later with a strain of infectious hepatitis also obtained in the Middle East. These results are in contrast to those found by Oliphant, who has described immunity in human subjects convalescent 6-19 months from homologous serum jaundice, when inoculated with serum from acute cases of infectious hepatitis. Using a strain of the naturally occurring disease, infectious hepatitis, no appreciable difference in incubation period was observed in experimental cases when equal amounts of the same infectious agent were inoculated parenterally or fed. Incubation periods ranged from 20-34 (average 24) days.

Failure to Transmit Infectious Hepatitis to Chimpanzees.

Summary 1. Two adult and 4 young chimpanzees were given material known to contain the etiologic agent of infectious hepatitis. Five of the animals remained healthy and showed no evidence of impairment of certain tests of liver function. One animal which was sick before beginning the experiment, died of a severe parasitic infestation 65 days after inoculation. The liver was normal grossly and histologically. Another animal died accidentally at the end of the period of observation and the liver was also normal. 2. Data are presented on serial determinations of certain tests of liver function in the chimpanzee. Quantitative determinations of serum bilirubin and per cent of bromsulfalein dye retention were of a lower order than similar determinations in normal humans. The cephalin flocculation was consistently positive in one apparently healthy adult animal and in one young chimpanzee with an overwhelming parasitic infestation. Three young healthy animals had consistently negative cephalin flocculation tests.

Elimination in human feces of infectious hepatitis virus parenterally introduced.

Summary 1. A strain of infectious hepatitis virus inoculated par enter ally into 8 human volunteers was recovered from pools of serum and feces obtained from these same subjects during the acute-phase of their illness. These materials produced infectious hepatitis in 5 out of 6 healthy, human volunteers on reinoculation. 2. This recovery of virus from the stool of patients with infectious hepatitis induced by parenteral inoculation constitutes an apparent difference between this condition and homologous serum jaundice in which the etiologic agent has not been recovered from the stool up to the present time.