U3.2 - Blood and Tissue Flagellates Flashcards
Flagellates that are found in the blood and other fluids (CSF) and in tissues
blood and tissue flagellates
Blood and tissue flagellates:
what kind of parasites
vector-borne
Blood and tissue flagellates:
Medically important genera
- Trypanosoma
- Leishmania
Blood and tissue flagellates:
MOT
Transmitted by a bite of an infected vector
Blood and tissue flagellates:
four morphological forms
- Amastigote – (Donovan Leishman)
- Promastigote – (Leptomonas)
- Epimastigote – (Crithidia)
- Trypomastigote
Blood and tissue flagellates:
All forms are found in?
Trypanosoma cruzi infections
Blood and tissue flagellates:
diagnostic stages
- trypomastigote
- epimastigote
- promastigote
- amastigote
Only the _____________ and _______________ are seen in Trypanosoma brucei infections
epimastigote
trypomastigote
Only the _____________ and _____________ are seen in Leishmania infections
amastigote
promastigote
Diagnostic Stages:
found in humans
amastigote and or trypomastigote
Trypanosoma cruzi:
Causative agent of?
Chagas disease or American trypanosomiasis
Trypanosoma cruzi:
habitat
- RES
- cardiac muscle
- CNS
Trypanosoma cruzi:
Intermediate host Vector
Reduviid Bug (kissing bug)
Trypanosoma cruzi:
MOT
- Feces of vector entering bite wound
- blood transfusion
- organ transplants
- transplacentally
Trypanosoma cruzi:
diagnostic stages in human body parts
- Trypomastigotes: bloodstream
- Amastigotes: tissue cells
Trypanosoma cruzi:
acute phase pathogenesis
- Non specific S/S: fever, malaise, nausea, vomiting, lymphadenopathy, cutaneous inflammation
- Chagomas
- Romaña’s sign
Trypanosoma cruzi:
chronic pathogenesis
Enlargement of vital organs (myocardium, megaesophagus)
Trypanosoma cruzi:
acute phase diagnosis
- Thick and thin blood smear using Giemsa
- CSF, tissue samples, lymph examination
- Concentration methods
- Blood culture
- PCR
- Xenodiagnosis
Trypanosoma cruzi:
chronic diagnosis
- ELISA
- Indirect hemagglutination
- Indirect immunofluorescence
- PCR
Trypanosoma cruzi:
acute phase treatment
- Nifurtimox
- Benznidazole
Trypanosoma cruzi:
chronic treatment
(symptom specific management)
1. Pacemakers
2. Antiarrhythmic drugs (amiodarone)
3. Megasyndromes are managed w/ special diets, laxatives, surgery
Trypanosoma cruzi:
epidemiology
- Most cases: Latin America
- Other cases reported in:
- Mexico
- USA
- Canada
- France
- Switzerland
- Japan
- Australia
prevention and control
- Vector control
- Blood transfusion regulations
- No vaccines available
Etiologic Agents of African Sleeping Sickness
Trypanosoma brucei complex:
1. Trypanosoma brucei rhodesiense
2. Trypanosoma brucei gambiense
3. Trypanosoma brucei brucei
Identify which Etiologic Agent of African Sleeping Sickness:
Causes Rhodesian or East African Sleeping Sickness
Trypanosoma brucei rhodesiense
Trypanosoma brucei rhodesiense:
endemic in?
East and South Africa
Identify which Etiologic Agent of African Sleeping Sickness:
Causes Gambian or West African Sleeping Sickness
Trypanosoma brucei gambiense
Trypanosoma brucei gambiense:
endemic in?
West and Central Africa
Identify which Etiologic Agent of African Sleeping Sickness:
affects wild and domestic animals
Trypanosoma brucei brucei
Trypanosoma brucei complex:
Vector
Tsetse fly (Glossina sp.)
Trypanosoma brucei complex:
only diagnostic stages exhibited
epimastigote
trypomastigote
Trypanosoma brucei complex:
Pathogenesis (Initial lesion)
local, painful, pruritic, erythematous chancre
Trypanosoma brucei complex:
Pathogenesis (early HAT)
- Hemolymphatic stage
- Fever, joint and muscle pain, malaise
- Winterbottom’s sign
Trypanosoma brucei complex:
Pathogenesis (late HAT)
- Meningoencephalitic stage
- Neurologic symptoms
- Convulsions, tremors, speech and reflexes defects, paralysis
- Kerandal’s sign
- Death
Trypanosoma brucei complex:
diagnosis
- Demonstration of trypomastigote in chancre, lymph node aspirate, CSF
- Thick and thin blood smear (Giemsa)
- Buffy coat concentration
- ELISA
- IFA
- Indirect hemagglutination
- Mini-anion exchange centrifugation technique
- PCR
- CATT
Trypanosoma brucei complex:
treatment
- Intravenous suramin solution: first stage of the disease
- Intravenous melarsoprol: if w/ CNS involvement
Trypanosoma brucei complex:
prevention and control
- Vector control
- Protective clothing
- Regulation and treatment of reservoir host (cattle and game animals)
Leishmania spp:
Divided into?
- Old World:
a. L. tropica
b. L. aethiopica
c. L. major - New World:
a. L. mexicana
b. L. amazonensis
c. L. guyanensis
d. L. braziliensis
e. L. chagasi
Leishmania spp:
vectors
- Old World: Phlebotomus sandfly
- New World: Lutzomyia
Leishmania spp:
type of parasite
Obligate intracellular parasite
Leishmania spp:
type of infection
Primarily a zoonotic disease
Leishmania spp:
MOT
- congenitally, blood
transfusion - contamination of bite
wounds - direct contact with
contaminated specimens
Leishmania spp:
pathogenesis (4 categories)
- Cutaneous Leishmaniasis (CL)
- Diffuse Cutaneous Leishmaniasis (DCL)
- Mucocutaneous Leishmaniasis (MCL)
- Visceral Leishmaniasis (VL)
Visceral Leishmaniasis (VL):
parasites
L. donovani complex:
1. L. donovani
2. L. chagasi
3. L. infantum
Visceral Leishmaniasis (VL):
acute phase may be mistaken for?
malaria
Visceral Leishmaniasis (VL)
cutaneous eruption resulting in hypopigmented macules, malar erythema, nodules, and ulcerations
Post- Kala-azar dermal leishmaniasis
Leishmania spp:
diagnosis
- Microscopic demo of Leishmania form lesions and tissue scrapings, aspirates, and biopsy
- Culture: NNN medium, Schneider’s medium
- Animal inoculation (hamster)
- Montenegro skin test
- Immunologic assays
Leishmania spp:
Immunologic assays
- ELISA
- rk39 Ag test (for VL)
- Direct agglutination
- Urine Ag test
- Flow cytometry
- PCR
- RFLP analysis
Leishmania spp:
treatment
Antimony compounds: IM or IV for up to 4 weeks; primary treatment
Leishmania spp:
epidemiology
- Primarily a disease of poverty
- VL is an important opportunistic infection in AIDS
Leishmania spp:
Prevention and Control
- Use of insect repellant (DEET & permethrin)
- Insecticide-treated clothing
- Fine-mesh bed nets
- Screens and sprays in houses
- Regulation of reservoir hosts