STUDIES ON MENINGOCOCCUS INFECTION : V. THE PRESENCE OF MENINGOCOCCUS PRECIPITINOGENS IN THE CEREBROSPINAL FLUID.

Precipitin tests, carried out on the cerebrospinal fluid from cases of meningococcal meningitis with monovalent sera, demonstrate the presence in that fluid of type-specific precipitinogens of the meningococcus. Negative results are secured when the spinal fluid is obtained after the commencement of intrathecal serum treatment and also occasionally when the numbers of infecting organisms are very small. The reaction offers an easy and rapid method of ascertaining to which type of meningococcus a particular case of meningitis is due, and facilitates the immediate use of monovalent therapeutic antimeningococcal serum. Typing by means of the precipitin reaction can be confirmed by agglutination of the strain of organism responsible for the infection, if such strain be isolated. Confirmation by means of agglutination has been possible in all the cases discussed in this report. Spinal fluids from other diseases of the meninges and central nervous system fail to give any precipitin reaction with the monovalent sera.