Leishmaniasis Flashcards
Leishmaniasis
-caused by intracellular protozoa
-3 main forms of leishmaniases
-20 species infect mammals
-much wider geographic range
Most important species in dog
Leishmania infantum
Leishmania lifecycle
-Sandfly takes bloodmeal ingesting macrophages from blood
-amastigotes transform into promastigotes in gut, divide and migrate to proboscis
-sandlfy bloodfeeds injecting promastigotes into skin
-Macrophages in humans ingest promastigotes
-promastigotes transform into amastigotes
-amastigotes multiply in cells of tissues and infect ofther cells
Morphological comparison of leishmania and T. cruzi
Leishmaniasis geographical location
-Africa
-South europe
-Asia
Leishmaniasis transmission
-Sandflies (90 species)
-can be passed vertically and by blood transfusions
Leishmaniasis in foxhounds
Endemic in these breeds in south-east and eastern US
-found in hunt clubs/kennel dogs of foxhounds
-linked to breeding and vertical transmission
Dog to dog transmission of leishmaniasis
-Proposed that rubbing of wounds, or fighitng may transmit disease
-asymptomatic possible so dont appear diseased
Leishmaniasis transmission in Europe
-Warming climate has expanded the range of sandflies and therefore expanded leishmania in Europe
3 types of LEishmaniasis
- cutaneous
- mucocutaneous
- visceral
*humans often only cutaneous, dogs develop all stages, cats mostly cutaneous;visceral ver uncommon in cats
Cutaneous leishmaniasis
-90% infected dogs
-open lesions at bite sites , hard thick tissue of muzzle and foot pads
-nodules and hard lumps
-coat may be dull, brittle and have hair loss
Visceral leishmaniasis
FATAL in humans and dogs
-fever, lack of appetite, weakness, exercise intolerance, severe weight loss, diarrhea, vomiting, bleeding from nose, blood in stool
-swollen lymph nodes, enlarged spleen and kidney failure
-muscle pain, join inflammation, sweelling of testicles
Diagnosis of Leishmaniasis
-Microscopy- needle aspirates of lymph nodes or bone marrow
-IFAs, ELISA
-PCR using blood or tissue
**remember there is cross reactivity between T. cruzi and Leishmaniasis
Tx of Leishmaniasis
-Glucantime- 6-12 mths (with allopurinol)
-Allopurinol 4+mths
-Miltefosine (with allopurinol)
**expensive, and long term
**often does not eliminate parasite and dogs remain carrier
**vaccines do exist for dogs
Leishmaniasis vaccines
-Letifend, CaniLeish, Leish-Tec
*none in canada or US
-only protect against one leishmania species= L. infantum/chagasi
-only protects for a year and dog cannot be currently infective
