Causes of Pneumonia

Viral Community-Acquired Pneumonia
In up to 30 percent of cases in adults, viruses are thought to be the cause of CAP. They are thought to be the most common pneumonia cause in children.
Some of the viruses known to cause CAP include:
Most cases of viral pneumonia are mild, and people get better in about one to three weeks without treatment. However, some cases are more serious and may require treatment in a hospital. If you have viral pneumonia, you run the risk of getting bacterial pneumonia also.
Fungal Community-Acquired Pneumonia
In people with normal, functioning immune systems, fungal CAP is uncommon. Fungi that are known to cause community-acquired pneumonia include:
  • Histoplasma capsulatum (found in the Ohio and Mississippi River Valleys)
  • Coccidioidomycosis (found in southern California and the southwest desert areas)
  • Cryptococcus.
Most people exposed to these fungi don't get sick, but some do and require treatment. Serious fungal infections are more common in people who have weak immune systems as a result of long-term use of medicines to suppress their immune systems or from having HIV/AIDS.

Hospital-Acquired Pneumonia Causes

Hospital-acquired pneumonia tends to be more serious than CAP. This is because the person is already sick. Also, hospitals tend to have more germs that are resistant to antibiotics, which is a treatment for pneumonia.
Some bacteria that can cause hospital-acquired pneumonia include:
  • Gram-negative bacteria, such as Escherichia coli, Klebsiella pneumoniae, Enterobacter species, Pseudomonas aeruginosa, and Acinetobacter species
  • Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA)
  • Streptococcus species.
Viruses and fungi are less likely to cause hospital-acquired pneumonia, except in people with a weakened immune system.
5 Tips to Keep a Cold at Bay

Pneumonia Information

Terms of Use
Advertise with Us
Contact Us
About eMedTV
Privacy Policy
Copyright © 2006-2019 Clinaero, Inc.
eMedTV serves only as an informational resource. This site does not dispense medical advice or advice of any kind. Site users seeking medical advice about their specific situation should consult with their own physician. Click Terms of Use for more information.