Transmission
Pneumonia is transmitted when germs from the body of someone with pneumonia spread to another person. This can happen in a variety of ways, including:
- Inhaling the infection. This can occur when a person with pneumonia coughs or sneezes and another person inhales the infected particles. This is more likely between people in close contact with each other, such as parents and children, or in poorly ventilated spaces, such as airplanes.
- Through the mouth or eyes. This can happen when a person touches a surface that an infected person has coughed or sneezed on. When a person with an infection coughs into their hand and then shakes another person’s hand, the second person can become infected if they touch their mouth or eyes without washing their hands.
Food particles and irritants from the intestinal tract can also cause pneumonia. This is called aspiration pneumonia and can occur when a person accidentally inhales these substances.
Aspiration pneumonia usually happens in people who have trouble swallowing, such as someone having a diagnosis of a stroke or other central nervous system conditions, such as Parkinson’s disease.
Fungal pneumonia typically develops when people inhale microscopic particles of fungus from the environment. People with weakened immune systems are more likely to develop this type of pneumonia. [2]