Airborne diseases, caused by microorganisms called pathogens, are primarily dispersed through moist air droplets or dust. Using air as transportation, pathogens use your respiratory tract as a channel for both entrance and exit via breathing, coughing or sneezing. Respiratory pathogens fall into three major disease-causing groups: viruses, bacteria and fungi. The spread of an airborne disease depends on the number of pathogens, the strength of the pathogen and your resistance to the disease.
Diseases such as the common cold, the flu, measles, mumps, rubella, fifth disease and chickenpox are airborne diseases caused by virus. Measles, mumps and chicken pox are usually considered childhood diseases, although they can affect adults. Cold and flu virus are transmitted in a similar fashion, although influenza viruses are stronger pathogens and can cause potentially deadly global epidemics. According to the Centers for Disease Control and Prevention, the flu tied with pneumonia as the ninth leading cause of death in the U.S. in 2010. (See Reference 5)
Tuberculosis, pneumonia, whooping cough, diptheria, meningitis and anthrax are examples of bacterial airborne diseases. (See Reference 1) Tuberculosis and bacterial pneumonia, despite the availability of vaccines, are still considered strong threats to mortality in the United States and the rest of the world. ( See Reference 2) Bacterial pneumonia tied with influenza as the ninth leading cause of death in the U.S. in 2010. (See Reference 5) According to the World Health Organization, tuberculosis remained in the top 15 causes of death in the entire world in 2011. (See Reference 6)
Fungal airborne diseases are primarily spread through the inhalation of spores. Unlike viral and bacterial airborne diseases, fungal airborne disease are almost entirely noncommunicable. Carpet and floor dusts, latex paint, moist building materials, molds, and mildews are all sources of fungal spores. Common fungal airborne diseases are EEA and HP which are usually associated with Sick Building Syndrome. Outdoor spores vary between climates and seasons tend to be inhaled in agricultural areas such as barns or work sheds resulting in a disease called Farmer's Lung. (See Reference 1)
As overcrowded spaces and poor sanitation are strong predictors of contracting an airborne disease, you can take precautionary measures to avoid becoming ill. Proper hand-washing is crucial. Most importantly, many airborne diseases are vaccine-preventable specifically, mumps, measles, rubella, and the flu. Vaccinations have enabled monumental gains towards the prevention of airborne diseases. (See Reference 4) Talk with your healthcare provider about what vaccinations you are eligible for, especially if you think you are at risk for contracting a disease.