GROUP OF PYOGENIC COCCI. 
53 
Infection with the pneumococcus takes place in 
two-thirds of the cases from outside the body, either 
directly from other patients or from infected dust. 
Carriers may transmit the infection but only to a 
limited extent. 
While the chief point of infection is in the lungs, 
the pneumococcus can be cultivated from the circulat¬ 
ing blood in a large proportion of the cases, indicating 
a general infection. With this in mind the complica¬ 
tions such as otitis media, pericarditis, endocarditis, 
meningitis, arthritis, and osteomyelitis are readily 
understood. Infections with the pneumococcus can 
occur in other parts of the body without pneumonia. 
To limit the spread of pneumonia the patient p ]jcau- 
should be isolated at once. In hospital practice the 
patient should be screened. The sputum should be col¬ 
lected in paper boxes or napkins and burned. The 
hands of the patient should be kept clean with disin¬ 
fectant (bichloride of mercury solution i: 1000) and 
the bed clothing disinfected. Rooms and apartments 
that have been occupied by pneumonia patients should 
be disinfected before being reoccupied. 
The immunity acquired by man during an attack immunity 
of pneumonia is of short duration. It has been pos¬ 
sible, however, to produce an active immunity in 
horses by inoculating them with cultures of the pneu¬ 
mococcus. The serum of such animals is protective 
to man only in the case of Type I infections. The type 
of pneumococcus infection in any given case must be 
determined for this reason. 
