<unk>  is caused by the bacteria Francisella tularensis which is typically spread by ticks, deer flies, and contact with infected animals. Bacteria Chocolate agar culture showing Francisella tularensis colonies Another culture of Francisella tularensis The bacteria can penetrate into the body through damaged skin, mucous membranes, and inhalation. Humans are most often infected by tick/deer fly bite or through handling an infected animal. Ingesting infected water, soil, or food can also cause infection. Hunters are at a higher risk for this disease because of the potential of inhaling the bacteria during the skinning process. It has been contracted from inhaling particles from an infected rabbit ground up in a lawnmower (see below).<unk>  is not spread directly from person to person. Humans can also be infected through bioterrorism attempts. Francisella tularensis can live both within and outside the cells of the animal it infects, meaning it is a facultative intracellular bacterium. It primarily infects macrophages, a type of white blood cell, and thus is able to evade the immune system. The course of disease involves the spread of the organism to multiple organ systems, including the lungs, liver, spleen, and lymphatic system. The course of disease is different depending on the route of exposure. Mortality in untreated (before the antibiotic era) patients has been as high as 50% in the pneumoniac and typhoidal forms of the disease, which however account for less than 10% of cases. Spread The most common way the disease is spread is via arthropod vectors. Ticks involved include Amblyomma, Dermacentor, Haemaphysalis, and Ixodes. Rodents, rabbits, and hares often serve as reservoir hosts, but waterborne infection accounts for 5 to 10% of all<unk>  in the United States.<unk>  can also be transmitted by biting flies, particularly the deer fly Chrysops discalis. Individual flies can remain infectious for 14 days and ticks for over two years.<unk>  may also be spread by direct contact with contaminated animals or material, by ingestion of poorly cooked flesh of infected animals or contaminated water, or by inhalation of contaminated dust.
Tularemia
Scabies
Chancroid
Smallpox
Chickenpox
Leprosy
Mumps
Polymeal