Airborne pathogens are disease-producing organisms which are carried and transmitted from one person to another through the air. These diseases can be as simple as the common cold, measles or chickenpox or as serious as tuberculosis, anthrax or smallpox. Airborne transmissions are characterized by an infected person coughing or sneezing in a relatively closed space with non-infected people.

Smallpox is an acute, contagious and sometimes fatal disease. It is caused by the variola virus and marked by fever and a distinctive, progressive rash. Smallpox was routinely vaccinated against in the United States until 1972 when the disease was effectively eradicated. Now, smallpox has become a concern once again through the threat of bioterrorism.

Smallpox is transmitted from contact with infected persons or infected body fluids.

An example of smallpox

Although there is no proven treatment for smallpox, there is again a vaccine to protect against smallpox infection. The vaccine is given in the upper arm with a small two-prong needle. The vaccine will provide immunity for 3-5 years, with decreasing immunity thereafter. The vaccine itself is not without risk. Based on previous experiences, 1-2 people per million vaccinated die from life-threatening reactions to the vaccine.

Severe Acute Respiratory Syndrome is a multi-country outbreak which first manifested on the continent of Asia. As of June 2003 there have been more than 7800 cases of SARS reported resulting in more than 650 deaths, mostly in Asia. The current mortality rate is just over 8% with higher mortality in the elderly. In the US, transmission has been limited to healthcare workers and travelers to suspect areas. The initial primary focus in the US is early identification of the disease and monitoring of the patients with suspected symptoms of SARS.

SAIZS is characterized by a fever greater than 100.4 degrees Fahrenheit, headache, body aches and mild to moderate respiratory symptoms. Routes of transmission can include inhalation, contact with infected droplets of the disease or close contact with an infected person. Currently, the treatment regimen includes similar intervention to that of basic pneumonia. Antiviral medications along with steroids are also being tested to combat this disease. Scientists (have discovered a previously unrecognized "coronavirus" in patients with SARS. This virus has a halo or crown-like appearance when viewed under a microscope. This virus can survive in the environment for up to 3 hours. The best mode of prevention is good personal hygiene and to avoid travel to countries with high SARS outbreaks.

Most people infected with WNV are asymptomatic. Rarely, severe symptoms such as meningitis, headache, high fever 8. coma can occur. Death occurs in very few of these infections. There is no specific treatment for WNV. Severe cases may require hospitalization, use of intravenous fluids and prevention of secondary infections.

To reduce your risk, avoid contact with mosquitoes and dead birds. Using gloves to handle potentially infected animals is your best course of action.