STUDIES ON MENINGOCOCCUS INFECTION : X. A FURTHER NOTE ON THE PRESENCE OF MENINGOCOCCUS PRECIPITINOGENS IN THE CEREBROSPINAL FLUID.

Precipitin tests have been carried out on spinal fluid from cases of meningococcal and other forms of meningitis, with monovalent anti-meningococcus horse serum of high titer. Using such a test it has been possible within 2 hours to diagnose and type cases of Type I and Type II meningococcal meningitis. In a certain number of cases fluids which were negative when first drawn became positive after standing for 1 or 2 days at 37 degrees C. or room temperature. In 9.5 per cent of all Type I cases the fluids did not become positive. Fluids from cases due to atypical meningococci may react with the type serum of the group to which they belong (i.e., Types II* and VII, which belong to group II, with Type II serum) but do not in every case. Fluids from forms of meningitis other than meningococcal give no reaction. The use of concentrated sera is not advantageous at present, owing to the heterologous reactions which occur.