Causes and Risk Factors
Up to 95% of acute bronchitis cases are caused by viral infections (Hueston 1998; Tackett, Atkins 2012). The most common viral causes are common cold viruses (also known as rhinoviruses) and the influenza and parainfluenza viruses. The majority of remaining cases are caused by bacterial infections and environmental irritants, such as pollutants, tobacco smoke, toxic fumes, and dust (Tackett, Atkins 2012; First Consult 2013). To combat acute bronchitis caused by pollutants and other environmental triggers, one should reduce exposure to them as much as possible.
Good hygiene, such as regular hand washing, is proven to limit the spread of viruses; therefore, it can impact the development of acute bronchitis (CDC 2012; A.D.A.M. 2012). In addition, infections with some viruses that cause acute bronchitis are more common and severe in colder weather, so taking extra precautions during winter months may help reduce risk (Dasaraju 1996; Lee 2012; Wenzel 2006). Additional risk factors include age (with very young and very old people being at higher risk for infections), immunization status (with people who did not receive vaccination being at higher risk), and working and living in crowded places, such as nursing homes, boarding schools, and military camps (First Consult 2013).