Pneumonia appears to be spread from person to person by contact, so it
is regarded as a communicable disease. As it is contagious, the spread
of infection can be stopped if precautions are taken to prevent the
transfer of the infectious material from the sick to the well. The
secretions from the nose and throat of persons sick with pneumonia,
or convalescing from the disease, usually carry the germs that cause
it. The transfer may take place through direct contact with these
secretions, or inhaling droplets of moist sputum expelled by the sick
person while coughing or sneezing.
Pneumonia is no respecter of persons. It may attack tiny babies, adults
in the prime of life, or elderly people: so everyone must be on guard.
This is especially true in late winter and early spring when the
disease is most likely to occur.
Pneumonia often begins during or just after an attack of the common
cold, grippe, whooping cough, or measles, and after surgical operations,
especially those upon the chest. In other conditions, such as unusual
and prolonged fatigue or exposure to bad weather resulting in a thorough
chilling, the chance of infection is increased.