Causes

Hospitals aren’t the only place you can get pneumonia. In fact, community-acquired pneumonia is actually more common. It affects people as they go about their everyday lives, outside of hospitals or health care settings.
 
Pneumococcal pneumonia is one kind of community-acquired pneumonia. It is caused by common bacteria called Streptococcus pneumoniae that many people typically carry in their throats without getting sick.
 
The most important thing to know about pneumococcal pneumonia is that you can get it anywhere. At any time. Even if you’re otherwise healthy.

Most cases of community-acquired pneumonia—including pneumococcal pneumonia—are caused when people inhale bacteria that live in the mouth, nose, or throat.