Parasitology Lecture 10 Flashcards
what insects transmits leishmaniasis?
sand flies
t or f: leishmania is an obligate intracellular pathogen
true
___ out of 30 species of leishmania can infects mammals
21
all species of leishmania are morphologically ________
indistinguishable
where is leishmania typically found?
in the tropics and subtropics
how many cases of leishmania are found worldwide?
12 million
t or f: most deaths from leishmania occur in kids
true (70% are kids)
what sand fly species is found in Africa & Asia?
phlebotomas
what sand fly species is found in Central & South America?
lutzomyia
when a sandfly takes a bloodmeal, it injects _______ into the skin, then these promastigotes are phagocytized by _________ and here they lose their ______ and become ________. this multiplication of ______ eventually ruptures the _______. then, a sandfly can come by and take a blood meal where it can ingest ______ that are infected with _______.
promastigotes, macrophages, flagella, amastigotes, amastigotes, macrophage
macrophages, amastigotes
in the midgut of the sandfly, the amastigote converts back into the _________ stage, where it divides and migrates to the ______
promastigote
proboscis
in leishmania, each parasite has a _____ and _______
nucleus + kinetoplast
t or f: in leishmania, both the nucleus and kinetoplast contain DNA, but the kinetoplast is larger
false - kinetoplast is smaller
the development of leishmania is thought to be an immune balancing act between the ___ and ___ responses
th1 and th2
which response favors worsening disease and increases parasite burden?
th2 (the humoral response)
which response favors tuberculoid/granulomatous disease and reduces parasite burden?
th1 (cellular immunity response)
what form of leishmania is known as the “balkh sore” or “oriental sore”
cutaneous leishmania
what form of leishmania is known as “espundia”
mucocutaneous leishmania
what form of leishmania is known as “kala-azar”
visceral leishmania
cell mediated immunity for cutaneous leishmania (CL) is usually ____, but ____ for visceral leishmania (VL)
strong, weak
while CL is ____, VL is quite ____
common
the natural course of most leishmania infections are formation of ____ then _______
boils, resolution
common agent behind CL?
L. tropica and L. mexicana
t or f: 90% of CL cases are in Afghanistan, Iran, Peru, Saudi Arabia, Syria, Brazil, Peru
true
at the height of infection, CL lesions have a “_____” appearance, where the edges are raised and there is a central ______
volcano, crater
if satellite lesions are found around the original ulcer, what could this be a sign of?
could be a sign that immunity is walling off and there is a risk of onward spread
true or false: a few cases of leishmaniasis have been detected in Texas and Oklahoma
true
define the term “autochthonous”
native to the place where its found
what is the agent behind MCL?
mostly L. braziliensis
90% of MCL cases are in Bolivia, ____, and _____
Peru, Brazil
MCL begins in the ____ cavity
nasal
what is the agent behind VL?
L. donovani
90% of VL cases occur where?
Bangladesh, India, Sudan, Ethiopia, Brazil
what is the mortality rate of VL if it is untreated?
95-100%!!!
what 2 organs are commonly enlarged due to VL?
spleen and liver (spleen is usually bigger)
define “hepatosplenomelagy”
enlargement of the spleen and liver
true or false: immunocompromised people are more likely to get severe leishmania
true
true or false: leishmania infection increase HIV acquisition risk 100-1000x
true
true or false: VL accelerates progression of HIV
true
true or false: HIV positive individuals who have VL are commonly seropositive
false - they are seronegative
what is diffuse cutaneous leishmaniasis (DCL)?
uncontrolled skin lesions all over the body
diffuse cutaneous leishmaniasis is clinically indistinguishable from ________
leprosy
t or f: DCL is due to the inability of the patient’s immune system to mount a complete immune response against its target
true
in order to diagnose leishmania, the lab should isolate the parasite with help from ______ labs. prior to collecting the specimen, they should be contacted.
reference
if the culture is positive, the species can be identified using ________ assays or using _______ analysis
DNA-based, isoenzyme
most sensitive leishmania tests?
molecular
for diagnosis of VL, _____ should be used
serology
for MCL diagnosis, biopsies can be used then a _____ or _____ test may be done
culture / molecular
for CL diagnosis, biopsies can be used then a _____ or _____ test may be done. also, skin scrapings can be taken from the lesion and a ______ stain can be done (3x)
culture / molecular, Giemsa
diagnosis can also be done by looking at intracellular ______
amastigotes
amastigotes are about ______ in diameter
1-5 microns
amastigotes lack ______
flagella
amastigotes divide by _____ ______ at 37 C
binary fission
leishmania amastigotes typically have a large ____, a prominent ______, but a short ______
nucleus, kinetoplast, axoneme
t or f: amastigotes are typically phagocytized and not found in blood
t
diagnosis can also be done looking at ________
promastigotes
promastigotes are typically _______ and found in blood as well as in the _____ of sandflies
flagellated, midgut
promastigotes have an elongated shape and are about ____ microns long
10-12
nucleus is found in the ____, the kinetoplast of promastigotes is typically found on the ______ end and this is also where the _____ is
center, anterior, flagellum
promastigotes can be found by taking a culture from the blood of a person and placing in ____ medium, where the amastigotes think they’re in a sandfly and transform into a promastigote
NNN
promastigotes bind to ______
macrophages
growing in a vacuole inside the macrophage allows leishmania to avoid _____ substances that the macrophages releases
lytic
all cases of ___ and __ should be treated but not all cases of ___ require treatment
MCL, VL, CL
treatments for leishmania?
- oral miltefosine
- liposomal amp B
- pentavalent antimonial compounds
prevention of leishmania?
- avoid nighttime activities because sandflies often bite then
- high grasses are more protective (sandflies fly low)
- deal with animal reservoir
