HUMAN INFECTION WITH VENEZUELAN EQUINE ENCEPHALOMYELITIS VIRUS

1X describing 2 cases of human infection, both mild and acquired in the labora¬ tory, reached our hands. It is our purpose in the present communication to describe 8 human cases of laboratory infection with the Venezuelan virus in which the clinical course of the disease varied from a com¬ paratively mild illness to a severe infection with mani¬ festations of central nervous system involvement. All 8 cases were proved immunologically to be due to the Venezuelan virus, and in 6 the virus was recovered. EPIDEMIOLOGY During the course of investigations on the causation of encephalitis following vaccination against yellow fever 12 it became desirable to make comparative studies on certain neurotropic viruses, and for this purpose an isolation section was temporarily established in the Yellow Fever Research Laboratory, it is located on the second floor of the building to segregate it from the laboratories (third floor) devoted entirely to yellow fever investigations. The section is quartered in a single large room, one portion of which contains the usual basic laboratory apparatus and supplies and the rest provides space for mice. It began to function in September 1941, the original personnel consisting of two physicians, E. H. L. and H. K., two technical assist¬ ants, G. D. and L. P. da S., and two animal caretakers and general utility men, C. P. O. and another person, A. F., who, at the time the laboratory infections reported here occurred was away on vacation, remained well and is therefore not considered further. J. D. B., technician, joined this group in September 1942, and J. S. R., animal caretaker, was added in January 1943. To keep the foreign viruses within the confines of the isolation section, a number of precautions were taken. No employee other than the section's personnel was permitted to enter, under threat of immediate dis¬ missal. All the viruses worked with were passaged, desiccated and stored in locked steel boxes in the sec¬ tion. No animal received in the section was permitted to leave alive, and all dead animals, cage refuse, floor sweepings and so on were collected in special recep¬ tacles. These containers with their contents were immersed in tanks of cresol solution for a minimum of one-half hour, but usually several hours, were with¬ drawn and allowed to drain, and the refuse was then incinerated. Mouse boxes were disinfected by similar From the Laboratory of the Yellow Fever Research Service, Rio de