猫引っかき病 (Cat-scratch Disease)

Cat-scratch Disease

I like cats, but they can harbor some pretty mean diseases. One of them is "cat-scratch disease."

Cat-scratch Disease is transmitted by a cat that has the bacterium Bartonella hensellae in its saliva or nails. B. hensellae is a rod-shaped, gram-negative organism that usually causes fever and regional lymphadenopathy in people with normal immune systems, but can also cause brain and retinal diseases in those with weakened immune defenses.

The incubation period is 1 -2 weeks and a brownish papule or pustule forms at the bite site in 50 -90% of the cases. Regional lymphadenopathy presents 3 - 10 days later and is frequently accompanied by fever, malaise and loss of appetite. Resolution usually occurs within a month.

A rare complication of cat-scratch disease is cat-scratch encephalopathy, which presents 1 - 8 weeks after lymphadenopathy.

Kittens tend to contract B. hensellae more than adult cats and can harbor the bacteria in their bloodstreams for up to one year. Fleas are carriers of B. hensellae and can spread the bacteria from cat to cat.

Link to photo of lymphadenopathy at www.doctorabel.us/systemic-disease/catscratch-disease-1.html.

Reference: Chamberlain, Neal. Medical Microbiology: The Big Picture: The Big Picture (LANGE The Big Picture) (Kindle Location 5668-5750). McGraw-Hill Education. Kindle Edition.

猫引っかき病

私は猫が大好きだけど、猫はかなりひどい病気の原因ともなることもある。その一つは『猫引っかき病』だ。

唾液または爪にBartonella hensellaeバクテリアに感染した猫が猫引っかき病を伝染する。B. hensellaeはグラム陰性桿菌で、正常な免疫系をもつ人間には発熱症状と局所リンパ節疾患を起こす。しかし、免疫不全なひとには脳や網膜の病気の原因ともなる。

潜伏期間は1～2週間で、50～90%の症例には茶色丘疹または膿疱が引っかき又は噛まれた場所にできる。局所リンパ節疾患がその3～10日間後に示される。発熱、全身倦怠感及び食欲不振も伴うこともある。回復は通常1ケ月以内。

猫引っかき病のまれな合併症は『猫引っかき脳症』である。リンパ節疾患の1～8週間後に起きる。

成猫よりも子猫が感染されやすい。B. hensellaeは感染された猫の血液内に1年まで存在できる。ノミはB. hensellaeの媒介生物であり、猫から猫への伝染を広げる。

参考：Chamberlain, Neal. Medical Microbiology: The Big Picture: The Big Picture (LANGE The Big Picture) (Kindle Location 5668-5750). McGraw-Hill Education. Kindle Edition.

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