In 1936 Scott and Rivers1 reported two cases of meningitis in man caused by a filtrable virus. The etiologic agent was isolated from the spinal fluids of the patients. The authors pointed out that their serums possessed neutralizing antibodies for at least 100 lethal doses of the virus from nine to eleven weeks after the clinical onset of the disease.
It is the purpose of this paper to report in detail three cases of acute lymphocytic meningitis. Serum taken from the first two patients in this series contained neutralizing antibodies for the virus of lymphocytic choriomeningitis. Serum from the third patient and from a control did not contain such antibodies.
The method employed in proving the presence of the antibodies was in part described by Rivers and Scott2 in 1936. It has been modified by Rivers recently and is briefly as follows:
A 10 per cent emulsion of