The usefulness of intracerebral neutralization, intraperitoneal neutralization, and complement-fixation tests for the diagnosis of human cases of western equine encephalomyelitis and St. Louis encephalitis was compared.
In cases of western equine encephalomyelitis it was found that the use of all three tests assisted in making the diagnosis, but that each method failed to demonstrate a significant antibody increase in more than one-fifth of the cases.
In cases of St. Louis encephalitis the intraperitoneal neutralization test was the most useful method. The intracerebral neutralization test showed an increase in antibody in only 7 of 20 cases.
Complement-fixation tests were valuable in the diagnosis of both western equine encephalomyelitis and St. Louis encephalitis.
These studies were conducted with the support of the International Health Division of The Rockefeller Foundation in cooperation with the California State Department of Public Health.