The value of the face mask and other measures in prevention of diphtheria, meningitis, pneumonia, etc.
Health authorities generally consider that pneumonia, epidemic meningitis and epidemic poliomyelitis as a rule if not always are transferred directly or indirectly from the sick to the well. This places them among the infectious diseases that have previously been considered contagious. Specific protective measures are available in smallpox, typhoid fever and diphtheria. In the other contagious diseases we must rely on mechanical measures and on germicidal agents and processes for the prevention of their spread.