Tularemia is a very rare disease that is caused by
the bacteria Francisella tularensis. It is often referred to as rabbit
fever or deerfly fever. Humans most commonly contract this disease by handling
or eating undercooked wild animal meat that has been infected by disease
carrying ticks. Rabbits are most commonly infected with the disease causing
bacteria although muskrats, hares and beavers also have been known to transmit
it.
Outbreaks of tularemia usually occur during hunting
season and summer months in which ticks and deerfly are widespread. These
insects carry the bacteria to the wild animals, which is how humans can
easily become infected with it when in contact with these animals. Infection
can also occur by when the skin, eyes, nose or mouth come in contact with
the bacteria in anyway. Drinking contaminated water or even breathing dust
from contaminated soil can transmit Francisella tularensis.
Depending upon where in the body infection occurs,
symptoms of tularemia can vary greatly. The bacteria can penetrate unbroken
skin but infection occurs usually through a scratch or bite. This results
in sores that occur where the bacteria infected the skin. Throat infection,
vomiting and diarrhea can occur by swallowing the bacteria. Inhaling the
bacteria can cause fever and a serious illness very similar to pneumonia.
Tularemia infection caused by Francisella tularensis.
Photo from University
of Kansas Medical Center
Francisella tularensis contains Gram negative, strict aerobes that are non-motile and can cause human infection. This bacteria requires the amino acid cysteine for growth and development. This makes it easily identified by using cysteine-blood agar in lab testing.
Bibliography
http://www.drkoop.com/conditions/encyclopedia/articles/020000a/020000201.html
http://www.state.hi.us/health/resource/comm_dis/cddtular.htm
http://www.dphhs.state.mt.us/hpsd/pubheal/disease/commdis/tuly.htm
http://www.adam.com/ency/article/00856.htm
http://medic.med.uth.tmc.edu/path/00001501.htm
http://www.pbrc.hawaii.edu/~kunkel/gallery/bacteria/page003/96528a.jpg
http://www.kumc.edu/instruction/medicine/pathology/ed/ch_9b/c9b_tularemia_eschar.html
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