Tularemia can appear in several different forms in humans, depending on the ronte of exposure. The usual presentation is ulceroglandular, typhoidal, or septicemic. In hummans, as few as 10-50 organisms can cause disease if inhaled or injected, but over 108 would be required for the disease if ingested. Ulceroglandular tularemia is acquired naturally from dermal or mucous exposures of blood or tissue fluids of infected animals. The typhoidal form makes up 5%-15% of naturally occurring cases, which result from inhalation of infectious aerosols. Pneumonia can result from any of the forms of tularemia, but is most prominent in typhoidal. Incubation periods range from 2 to 10 days, depending on the doseoute of exposure incubation period occurs within 3 days.