Plague cases in the United states during the 1980s averaged around 18 per year, mostly in the Southwestern states of New Mexico, Arizona, Colorado, and California. Highest rates of infection occur among Native Americans, particularly the Navajos. Others at risk include hunters, veterinarians, pet owners, campers, and hikers. Of those, most cases involved persons that were under the age of 20, with a fatality rate of one in seven. Death rates from bubonic plague can reach as high as 50%-60% if not treated. when treated, the death rate is reduced to about 15%. If treatment is not begun within 24 h after symptoms develop, pneumonic plague has a near 100% death rate. Plague can also be transmitted when the organism enters the body through a break in the skin. This type of exposure occurs from direct contact with tissue or body fluids of a plague-infected animal, such as skinning a rabbit or other animal. This is, however, a rare occurrence. Plague can also be transmitted through inhalation by contacting by contacting infected droplets from a person or domestic animal coughing. Plague that develop from this type of exposure is called pneumonic. This infection involves the lungs as a result of inhalation of organisms, which results in primary pneumonic plague. Secondary pneumonic plague results from septicemia (blood infection) when the organisms spread to the lungs.