That influenzal cerebrospinal meningitis is by no means a rare affection is being shown by the increasing number of reports of its occurrence. Within a few months, in the United States alone, reports dealing with the subject have been published by Wollstein, Dunn, and Davis. Moreover, the disease is highly fatal. All but six of the fifty-eight cases thus far reported in which the influenza bacillus has been detected in the cerebrospinal fluid, have terminated fatally.
Influenzal meningitis is more frequent among infants and children than among adults. It sometimes follows on undoubted influenza bacillus infections of the respiratory tract, and sometimes develops independently of obvious disease of that tract. Since the influenza bacillus is often present in the secretions of the respiratory mucous membrane in children, suffering from a variety of diseases, during the wide prevalence of influenza, it is probable that the infection of the meninges is always