The main cause of pneumonia is often bacterial infection, most commonly by Streptococcus pneumoniae (pneumococcus).
While various factors can lead to pneumonia, bacterial infections are a significant contributor, particularly in adults. Here's a more detailed breakdown:
- Bacteria: Streptococcus pneumoniae is the leading bacterial cause of pneumonia in the United States. Other bacteria can also cause pneumonia, sometimes with different symptoms or characteristics.
It's important to note that while bacteria are the most common cause, pneumonia can also be caused by:
- Viruses: Respiratory viruses like influenza (flu), respiratory syncytial virus (RSV), and rhinoviruses (common cold) can cause viral pneumonia.
- Fungi: Fungal pneumonias are less common and typically affect individuals with weakened immune systems.
- Other Organisms: Mycoplasma pneumoniae, a type of bacteria-like organism, can cause "walking pneumonia," a milder form.
Therefore, while multiple agents can cause pneumonia, Streptococcus pneumoniae is the most prevalent bacterial culprit, making bacteria the overall primary cause.
