More in this Section: Introduction | Awareness | Causes | Treatment
Pneumonia is an Acute Respiratory Infection (ARI) of the lower respiratory tract, specifically the bronchial tubes and lungs. Infections of the bronchial tubes and lungs are called Lower Respiratory Infections. Pneumonia, the chief and most deadly among them is an acute infection of the lungs. Tuberculosis is also an Acute Respiratory Infection of the lungs.
When someone is sick with pneumonia, microorganisms such as viruses or bacteria enter the tiny alveoli in the lungs (where oxygen enters the blood and where carbon dioxide leaves the blood). Ironically, it is partly because of the body's defense mechanism that pneumonia begins. As white blood cells, immune proteins, and foreign materials build up, the alveoli fill with pus and fluid - obviously detrimental to the absorption of oxygen, as it makes breathing a strenuous task. Other symptoms include high fever, vomiting, cough, chills, headaches, and loss of appetite.
There are four basic types of pneumonia:
- Community-Acquired Pneumonia Community-acquired pneumonia is pneumonia that is developed outside of a hospital. It is the most common type of pneumonia. In the United States, between 2 - 4 million people will develop this each year, resulting in 600,000 hospitalizations.
- Hospital-acquired (Nosocomial pneumonia) The other, less common form of pneumonia which affects five to 10 out of 1000 hospitalized people yearly. People in the hospital have a higher risk of developing pneumonia compared to those outside a hospital, and this type of pneumonia can be very serious and deadly.
- Aspiration pneumonia Aspiration pneumonia occurs when foreign materials are inhaled into the lungs (such as when the gag reflex is suppressed)
- Pneumonia caused by opportunistic organisms This is a type of pneumonia that most often occurs in those who have weakened immune systems. It is especially dangerous to those who take immunosuppressant medication.
Most victims of pneumonia and other acute respiratory infections are children under five years of age. In this age group, 20% of all deaths are caused by acute respiratory infections, of which 90% are cases of pneumonia. Two million children die each year because of pneumonia. This statistic does not include pneumonia deaths in the first four weeks after birth - if it did, then the deaths of children under 5 would soar to 3 million each year. The sad fact is that 99% of these deaths take place in the developing world. Acute Respiratory Infections also result in the most Disability Adjusted Life Years (or DALYs, the sum of years of potential life lost due to premature mortality and the years of productive life lost due to disability) lost each year, according to WHO.
(Source: Extracted from 1998 WHO Report, see the original figure and associated discussions on the WHO website)
In 1998, Acute Respiratory Infections resulted in 83 million DALYs lost, while diarrheal diseases resulted in 73 million and HIV/AIDS resulted in 71 million.
Michael G (14) and Patrick G (12), Doors to Diplomacy 2007