Transcript Document

報告人：張聰舜
報告日期：2006-2-13
A male immigrant from Mexico was seen in the
dermatology clinic at a California hospital for
examination of a large, painless, cutaneous ulcer
on his ear. There was evidence of cartilage
destruction in the area. A biopsy specimen was
taken from the skin lesion and was sent to the
laboratory for examination. A section stained with
hematoxylin and eosin showed small, oval,
nonflagellated protozoan amastigotes. A diagnosis
of a blood-borne parasitic infection was made,
based on the morphological appearance of the
Giemsa-stained smear.
Leishmania mexicana complex
Classification
 原生動物界（Protista）－原生動物亞界（Protozoa）－
變形鞭毛蟲門（Sarcomastigophora）－鞭毛蟲亞門
（Mastigophra）－動鞭毛蟲綱（Zoomastigophorea）－
動質蟲目（Kinetoplastida）
利什曼原蟲（Leishmania）
錐蟲（Trypanosoma）
Classification
 L. donovani
 L. donovani donovani、L. donovani chagas、L. donovani infantum
 L. tropica
 L. tropica aethiopica、 L. tropica major、 L. tropica minor、 L. tropica
tropica
 L. maxicana
 L. maxicana amazonensis、 L. maxicana mexicana、 L. maxicana
pifanoi
 L. viannia（L. braziliensis）
 L. viannia braziliensis、L. viannia guyanensis、L. viannia panamensis、
L. viannia peruviana
Classification
臨床表徵
相關種類
舊世界
L. donovani
新世界
L. donovani
rare
L. viannia
L. tropica
L. viannia
L. mexicana
Visceral
Mucocutaneous
Cutaneous
Epidemiology
 North-Eastern China, India, Middle-East, Southern Europe (Mediterranean bassin),
Northern Africa, Central-East Africa and, in foci, Central and South America
(especially Brazil and Honduras).
Epidemiology
 O.W.L. is found especially in Asia (Middle East), Northern Africa and
Southern Europe.
 N.W.L. has a wide distribution in Central and South America (from Yucatan
to Brazil).
 The mucocutaneous form is prevalent in South America.
Life Cycle
 無鞭毛體 amastigote (Leishman-Donovan body)
 found intracellularly in the vertebrate (i.e., human) host
 前鞭毛體 promastigote (leptomonad)
 found in the digestive tract of the invertebrate host
Life Cycle
Vector
 Sandfly（白蛉）：order Diptera（雙翅目）－ family Phlebotomidae
（白蛉科）or Psychodidae （毛蠓科 ）. It includes the genera as follows：
 Phlebotomus genus（白蛉屬）
 Lutzomyia genus（沙蠅屬）
 Psychodopygus genus
Sandfly
 small size, long legs, and abundant hair on both wings and
body
 flying, biting, blood-sucking insect
 Most sandflies will bite any warm-blooded animal and one
species attacks penguins.
 Only female sandflies bite
 New world－ Lutzomyia
 Old world－ Phlebotomus
Animal reservoirs
人畜共通病（Zoonosis）
齧齒目動物 ,樹懶 ,有袋動物 ,食肉動物
印度的Vsceral Leishmaniasis 幾乎侷限於
人
 L. major 在亞洲鄉村是野生齧齒;在亞洲都
市是犬;在非洲市齧齒
Cutaneous leishmaniasis
 O.W.L. is found especially in Asia (Middle East), Northern Africa and
Southern Europe.
 N.W.L. has a wide distribution in Central and South America (from Yucatan
to Brazil).
 The mucocutaneous form is prevalent in South America.
Cutaneous leishmaniasis




incubation period is 2~8 weeks
erythematous papule nodule nodule ulcerates and crusts
typically large but painless unless there is secondary bacterial or fungal infection.
Old World Cutaneous leishmaniasis
 Leishmania, subgenus Leishmania, complexes major, tropica, donovani (infantum
species), aethiopica (diffuse form).
 dry or urban cutaneous leishmaniasis is caused by Leishmania tropica
 wet or rural cutaneous leishmaniasis is caused by L. major
 Ethiopian cutaneous leishmaniasis is caused by L. aethiopica
 New World Cutaneous leishmaniasis
 Leishmania, subgenus Leishmania, complex mexicana (mexicana, amazonensis, pifanoi)
and subgenus Viannia, complexes brasiliensis and guyanensis
 develop and heal similarly to those of the Old World forms but tend to be less
nodular and more ulcerative and destructive
 some common forms are mucocutaneous leishmaniasis
Old World Cutaneous leishmaniasis
 dry cutaneous





large urban areas in the Middle East, the Mediterranean region, and the Indian subcontinent
Leishmania tropica
vectors Phlebotomus sergenti and P. papatasi
reservoir may be either human or canine（犬）
A slowly developing single lesion that persists for a year or more
 wet cutaneous





rural areas in parts of the Middle East, central Asia, and the Indian subcontinent
Leishmania major
reservoirs are desert rodents such as squirrels（松鼠） and gerbils （沙鼠）
vector Phlebotomus papatasi
Infection is acute, rapidly evolving, and characterized by multiple sores with inflammation, ulceration,
and crusting
 Ethiopian cutaneous






the highlands of Kenya and Ethiopia
Leishmania aethiopica
hyraxes（蹄兔）
vectors are Phlebotomus pedifer and P. longipes
less inflamed and more chronic
self-limited but may develop into diffuse cutaneous leishmaniasis
Old World Cutaneous leishmaniasis
New World Cutaneous leishmaniasis
 Mucocutaneous
 chronic, progressive metastatic spread of the lesions of New World cutaneous
leishmaniasis
 Leishmania viannia braziliensis
 nasal, pharyngeal, and buccal mucosa months to years after the appearance of the initial
cutaneous lesion,which has usually healed.
 mutilating destruction of the nasal septum, palate, lips, pharynx, and larynx
Diffuse cutaneous leishmaniasis






rare chronic form
Leishmania aethiopica in Ethiopia and Kenya
L. pifanoi in Venezuela
L. viannia in South America
L. mexicana complexes in Central America
local and hematogenous spread from a primary lesion to produce
generalized nodular lesions resembling those of lepromatous leprosy in the
skin and sometimes involving the nasal mucosa and laryngopharynx.
Diagnosis
 a history of exposure to sandfies
 Risk factors for HIV should besolicited, including sexual encounters,
intravenousdrug use, and blood transfusions obtained abroad.
 symptoms
 isolation of the organisms from the lesion aspirate or biopsy, by direct
examination or culture
 A skin test (delayed hypersensitivity: Montenegro test) and detection of
anti-leishmanial antibodies by immuno-fluorescence are indicative of
exposure.
Diagnosis
Diagnosis
 Cutaneous scraping
 the simplest and most common test
 only 70 to 75 percent sensitive
 fixed with methanol, stained with Giemsa, and examined under oil immersion.
 Amastigotes are seen in monocytes or extracellularly
 It is important to see the nucleus and the rod-shaped kinetoplast, a
mitochondrial structure containing extranuclear DNA, to diagnose
leishmaniasis.
Treatment
 Sodium stibogluconate is the drug of choice.
 Machanism unknown
 Side effect（reversible）
Gastrointestinal symptoms
Fever
Headache
Myalgia , arthralgia
Rash
ECG changes, ex. T waves change and QT prolongation
Treatment
Quiz 1
 Which infection does this patient have? What is
the name of the hemoflagellate causing his
infection?
Quiz 2
 Name the three main species belonging to this
complex.
Quiz 3
 Which vector is responsible for the transmission
of this infection?
Quiz 4
Describe the life cycle of this parasite.
Quiz 5
What are the reservoirs for these parasites?
Which populations are at particular risk of
infection with these parasites?
Quiz 6
How is the diagnosis of this infection made?
Quiz 7
How is this infection treated?
Reference







醫用寄生蟲學
http://www.cdfound.to.it/html/atlas.htm#atlas
http://www.biosci.ohio-state.edu/~parasite/home.html
http://en.wikipedia.org/
http://www.dpd.cdc.gov/dpdx/Default.htm
http://pathmicro.med.sc.edu/book/welcome.htm
Basic and clinincally pharmacology