Trypanosomiasis & Leishmaniasis Flashcards
describe epidemiology of Trypanosoma
host specific
euryxenous (affect wide ranges animals)
affects mammals, bird, reptiles, amphibians
describe visual characteristics of Trypanosoma
elongated, spindle shape cell
single nucleus, posterior flagellum and lots of DNA
what is a kineoplast?
all the DNA within Trypanosoma
what are the transmission routes for Trypanosoma?
insect vectored (salivarian or stercorarian aka via feces)
latrogenic (blood contamination, needle, etc)
transplacental
what species are affected by tsetse- transmitted African Trypanosoma?
domestic ruminants
equids
pigs
dogs
cats
where can you find tsetse- transmitted African Trypanosoma?
Sub-Saharan Africa
which Trypanosoma cause Nagana disease?
tsetse- transmitted African
T. brucei
T. congolense
T. vivax
how is Nagana disease transmitted?
bites of tsetse flies (Glossina spp)
what are the possible disease stages of tsetse- transmitted African Trypanosomes in ruminants?
acute, chronic, asymptomatic
explain the acute disease of tsetse- transmitted African Trypanosomes in ruminants
high parasitemia (in blood), extensive hemorrhage of mucosa and serosa surfaces of body
explain the chronic disease of tsetse- transmitted African Trypanosomes in ruminants
anemic, emaciated with signs of wasting
what disease is caused by Non-tsetse dipteran vectored trypanosomes?
Surra disease
what causes Surra disease? which species?
T. evansi
domestic animals
what are clinical signs of Surra disease?
NO pathognomonic signs or macroscopic lesions
broad signs (fever, weight loss, etc)
what are the vectors of Surra disease?
Tabanid flies (horseflies)
vampire bats
which trypanosome disease is sexually transmitted?
Dourine
which species is affected by Dourine?
equines
what causes Dourine in horses?
T. equiperdum
explain the acute stage of Dourine
genitalia swelling
mucoid discharge
how is Dourine transmitted?
direct sexual contact
what is indicated in the image of a horse limb? what stage of dourine is this?
“silver dollar” plaque
appears as the acute stage comes to an end
explain the chronic stage of dourine
emaciation
paresis
fever
death
how would you clinically diagnose Nagana disease?
direct visualization of trypanosomes
indirect fluorescent assay, ELISA (high specificity and sensitivity)
how would you clinically diagnose Surra disease?
microscope exam
PCR
ELISA (for T. evansi)
how would you clinically diagnose Dourine?
serology (NOT specific)
complement fixation test
which two species are not easily differentiated in serology for diagnosing Dourine?
T. brucei and T. evansi
*must take other clinical signs into account
what’s the disease caused by American triatomine-transmitted trypanosomes?
Chagas disease
what causes Chagas disease?
T. cruzi
Chagas disease reservoir hosts
opossums, armadillos, rodents, cats, monkeys, raccoons, pigs
what’s the main route of infection for Chagas disease?
vector borne via Triatomine/kissing bugs
where is Chagas disease mostly reported?
South US
Texas, Louisiana, Tennessee
list the at-risk populations for Chagas disease
young dogs, working dogs, puppies from diseased moms, outdoor dogs
what are the three phases of Chagas disease?
acute
latent
chronic
what do the three stages of Chagas disease have in common?
could result in sudden death at ANY stage
explain the acute phase of Chagas disease
fever, anorexia, lethargy, lymphadenopathy, hepatomegaly, splenomegaly, cardiac abnormalities
*very broad issues
explain the latent phase of Chagas disease
NO clinical signs, but sudden death could occur
explain the chronic phase of Chagas disease
congestive heart failure, dilated CM, arrhythmias
what is the standard method of diagnosing Chagas disease?
serology via indirect fluorescent antibody
explain the treatment of Chagas disease
NO effective drugs
manage symptoms
how do you prevent Chagas disease?
limit contact with triatomine vectors
prevent dogs from eating potentially infected animals (mice, rat)
test breeding females to prevent congenital transmission
describe epidemiology and biology of Leishmania species
protozoan parasite
found on ALL continents except Antarctica
(including North America)
which species is most affected by Leishmania?
DOGS
list the modes of transmission of Leishmania
vector borne by sandflies
latrogenic transmission via blood transfusion
transplacental
what’s the most common cause of canine Leishmaniasis?
L. infantum
what are the risk factors for dog infection of Leishmaniasis?
> 2 years old
prolonged exposure to outdoors
lack of tropical insecticide use
short haircoat
is it common for dogs to develop life threatening disease from Leishmania?
NO, they usually eliminate the infection or remain sub-clinically infected (possible reactivation later in life)
what’s the incubation period for Leishmania?
long time, about 7 years
what is this?
cutaneous Leishmaniasis
describe what occurs with cutaneous Leishmaniasis
alopecia, scaling, ulceration
many dogs also develop onychogryphosis (long, brittle nails)
what is this?
visceral Leishmaniasis
describe the signs of visceral Leishmaniasis
fever, weight loss, oral ulcers, progressive lymphadeno/spleno-megaly, mucosal pallor due to anemia, rarely hepatomegaly
what does the development of autoantibodies and circulating immune complexes lead to in patients with visceral Leishmaniasis?
immune mediated thrombocytopenia and/or thrombocytopathia
epistaxis or melana, lameness, joint swelling
how would you diagnose canine Leishmaniasis?
clinical suspicion and history (travel history)
microscopy
serology
PCR
what are the two common pathogenesis of canine Leishmaniasis?
cutaneous and visceral
