Causes of Pneumonia

In our previous post we describe that What is Pneumonia? Now we describe Causes of Pneumonia.Pneumonia has many possible causes, but the most common ones are Bacteria , Viruses and Fungi.Sometimes though Germs manage to enter the lungs and cause infections.

 Germs That Can Cause Pneumonia: 
  
 Bacteria: 

 Bacteria are the most common cause of pneumonia in adults.Many types of bacteria can cause pneumonia.Streptococcus (S.) pneumoniae (also called pneumococcus), the most common cause of pneumonia.Staphylococcus (S.) aureus,one of the other major Gram-positive bacterium responsible for pneumonia,

 Viruses: 

 A number of viruses can cause pneumonia, either directly or indirectly. About half of all people with pneumonia have viral pneumonia. It is more common in children.respiratory syncytial virus (RSV), and parainfluenza virus are all potential causes of viral pneumonia. Viral pneumonia is usually less serious than bacterial pneumonia and can take from two to four weeks to recover.

 Fungi: 

 Fungal pneumonia is uncommon, but occur more commonly in individuals with weakened immune systems.Histoplasmosis, coccidiomycosis, blastomycosis, aspergillosis, and cryptococcosis are fungal infections that can lead to fungal pneumonia. Most people exposed to these fungi don't get sick, but some do and require treatment.

 Parasites: 

  A variety of parasites can affect the lungs, including: Toxoplasma gondii, Strongyloides stercoralis, Ascaris lumbricoides, and Plasmodium malariae. Most cases of parasitic pneumonia occur in people who live or have traveled in developing countries.

 Nosocomial and others: 

 Organisms that have been exposed to strong antibiotics and have developed resistance are called nosocomial organisms. If they enter the lungs, a person may develop nosocomial pneumonia. Resistant bacteria are often found in nursing homes and hospitals. An example is MRSA, or methicillin-resistant Staph aureus, which can cause skin infections as well as pneumonia. Similarly, outbreaks of the H5N1 influenza (bird flu) virus and severe acute respiratory syndrome (SARS) have resulted in serious pneumonia infections. Anthrax, plague, and tularemia also may cause pneumonia, but their occurrences are rare.