If you are suffering from bronchitis, or have a friend or loved one who is, you may be wondering, “Is bronchitis contagious?” The answer depends on the type of bronchitis and the underlying cause.
Ninety-five percent of cases of acute bronchitis are caused by viral infections that enter the respiratory system and cause inflammation of the bronchial tubes.  The most common viral causes of acute bronchitis are the rhinovirus, otherwise known as the common cold, influenza A and B, adenovirus, and parainfluenza virus.  The viruses that cause acute viral bronchitis are contagious, but they may or may not lead to an inflammation of the bronchial tubes in someone else. Less frequently, bacteria cause bronchitis. Again, the bacteria that can lead to bacterial bronchitis are contagious, but they may or may not lead to bronchitis in another person. Acute bronchitis caused by environmental factors such as air pollution, dust, or exposure to chemical fumes is not contagious. In rare cases acute bronchitis is caused by fungus. Technically, this type of bronchitis is contagious, but it usually only infects people with compromised respiratory or immune systems, such as those with asthma or HIV.
Because chronic bronchitis, or bronchitis that lasts longer than three months, is generally caused by behaviors and environmental factors such as smoking, air pollution, and exposure to chemical irritants, it is not considered to be contagious.
How Bronchitis Spreads
The bacteria, viruses, and fungi that can cause acute bronchitis are contained in the spittle that exits the body each time an infected person sneezes or coughs. A second person can become infected by directly inhaling this mist, or by shaking hands with an infected person and then infecting themselves by touching their faces before washing their hands.
It is always best to avoid infected people, but that’s often impossible. Diligent hand washing or the use of a hand sanitizer can help prevent infection. It is always best to avoid touching your face unless you have just washed your hands. Vaccinating yourself against the flu and pneumonia can also help prevent bronchitis, as these viruses can lead to bronchitis. Avoid behaviors such as smoking, which can weaken your respiratory system’s ability to fight off infection.
 American Family Physician, WILLIAM J. HUESTON, M.D
February 20, 2013
 Canadian Family Physician, Graham Worrall
2008, Volume: 54, No: 2, pages: 238-239
February 20, 2013
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