Lower respiratory tract infections
Cases of pneumonia make up the vast majority of debilitating lower respiratory tract infections, which affect the trachea, lungs and bronchi, according to the World Health Organization. Bronchitis and bronchiolitis, which cause inflammation of the bronchi, also fall into the same category.
Pneumonia, an inflammation of the lungs, can be deadly if that inflammation fills the air sacs in the lungs and interferes with breathing. In some cases, the infection can invade the bloodstream and spread quickly to other organs.
Global Impact
An estimated 4 million people died in 2004 from lower respiratory infections. Worldwide, pneumonia is the leading cause of death in children. About 20 percent of all deaths in children under 5 years old are due to acute lower respiratory tract infections and 90 percent of these deaths are due to pneumonia, according to the World Health Organization.
In the United States, more than 60,000 Americans die of pneumonia each year, according to the Mayo Foundation for Medical Education and Research.
Causes
Pneumonia can be caused by bacteria, viruses or fungi, and can follow acute or chronic bouts of bronchitis. It is also possible to get pneumonia by accidentally inhaling a liquid or chemical.
Transmission of pneumonia from person-to-person through direct contact with infectious secretions can occur, however most infections are not caught from another person but are a product of a weakened immune system. Hospital patients are at an especially high risk of pneumonia.
A bacterium is the most common cause of pneumonia in
adults and children over the age of three. Bacterial pneumonias tend to
be the most serious and among the elderly can be brought on after
influenza or the common cold.
Respiratory viruses are the most common cause of pneumonia in young children, according to the National Institutes of Health.
Bronchitis,
which is an inflammation of the main air passages to the lungs, is
generally caused by viral respiratory infections. The main cause of
chronic bronchitis is cigarette smoke, or long-term exposure to
secondhand smoke. The affliction usually clears up on its own, but it
can lead to pneumonia in some severe cases.
Symptoms
Pneumonia has similar symptoms to a cold or the flu at its onset, with a cough and fever. The main signs and symptoms are often shaking, chills, a high fever, sweating, shortness of breath, chest pain, and coughing greenish or yellow phlegm.
Additional symptoms can include headache, excessive sweating, loss of appetite, excessive fatigue and confusion, especially in the elderly.
Prevention
Vaccines can help prevent pneumonia in children, the elderly and those with chronically debilitating conditions or diseases such as HIV. The pneumococcal vaccine prevents the most common form of bacterial pneumonia, Streptococcus pneumoniae. Getting a flu vaccination can help prevent an illness that would develop into pneumonia, while the Hib vaccine prevents pneumonia in children from Haemophilus influenzae type b.
Smoking is discouraged because it damages the lungs' natural defenses against disease. Not smoking, or quitting smoking are recommended to prevent both pneumonia and bronchitis, as well as limiting exposure to air pollutants and washing hands regularly to avoid spreading infections and viruses.
Treatment
Pneumonia treatments vary depending on the cause and severity. Bacterial pneumonia is treated with antibiotics, while most viral pneumonias are treated the same way as the flu, with rest and fluids. Pneumonia caused by a fungus is usually treated with antifungal medication.
Severe pneumonia leads to hospitalization and treatment with intravenous antibiotics and oxygen.
Sources: National Library of Medicine, National Institutes of Health, the Mayo Clinic, the New England Journal of Medicine, University of Maryland Medical Center
