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Kinetoplasta
(Trypanosoma & Leishmania)
Leishmania
A genus of trypanosomatid protozoa and is
the parasite responsible for the
disease leishmaniasis.
The parasite was named in 1903 after
the Scottish pathologist William Boog
Leishman.
Leishmania are unicellular
eukaryotes having well-defined nucleus and
other cell organelles
including kinetoplast and flagellum.
Structure
Digenetic or heteroxenous parasites.
Life cycle involves two hosts, a vertebrate and an invertebrate, the sandfly.
In Leishmania, the life cycle stage in the vertebrate is the amastigote and in the insect, the promastigote.
Exist in two basic body forms: the amastigote, the intracellular form in the vertebrate host and the promastigote, the extracellular form in insect the sandfly (Phleobotomus spp. and Lutzomyia spp.) vector.
Amastigotes are taken up from the blood
of an infected host when the female
sandfly bites, and in the sandfly gut they
develop into promastigotes where they
multiply by binary fission.
Promastigotes move anteriorly into the
proboscis and are introduced into the
vertebrate host when the sandfly bites
again. The promastigotes injected by the
sandfly during feeding are phagocytized
and develop into intracellular amastigotes.
Amastigote
Small spherical non-flagellated cells
ranging from 2-4µm in diameter.
The nucleus and kinetoplast are
surrounded by small ring of
vacuolated cytoplasm.
The cells are among the smallest
nucleated cells known.
Promastigote
Thin elongate cells with an anterior
kinetoplast.
An emergent free flagellum.
Generally lance-like in shape and
range in size from 5-14µm in length by
1.5-3.5µm in width.
Disease
Leishmaniasis
Caused by protozoan parasites of the genus Leishmania.
Spread through sandflies of the genus Phlebotomus in the Old World, and of the genus Lutzomyia in the New World.
3 types of the disease :
-cutaneous leishmaniasis
-mucocutaneous leishmaniasis
-visceral leishmaniasis
Major species of
Leishmania
and
their geographic
distribution
Cutaneous Leishmaniasis
- the most common form of the disease, causes ulcers on exposed parts of the body, leading to disfigurement, permanent scars, stigma and in some cases disability.
Visceral Leishmaniasis or kala-azar
- the most severe form of the disease, can cause fatal if left untreated. The disease can affects the vital organs of the body.
Mucocutaneous Leishmaniasis
- the most destructive form of the disease, causes partial or total mutilation of mucous membranes in the nose, mouth and throat.
Photo credit : Jean Fortunet Photo credit: B. Arana, MERTU, Guatemala
Cutaneous Leishmaniasis
Visceral Leishmaniasis or kala-azar
Photo credit : Prof Eyckmans
Photo credit : C. Bern, CDC
Mucocutaneous Leishmaniasis
Photo credit :
Uniformed Services
University of the Health Sciences
Photo credit : Abdul Dr Ghaffar
Transmission organism
The only proven route of infection is by the bite of female phlebotomine sand flies.
Phlebotomine sand flies bite humans and some animals, and take blood meals to feed the development of their eggs.
When sandflies take blood meals from an infected person, they also become infected with the protozoa that cause leishmaniasis. .
The protozoa develop inside the sandflyand are passed on when the sandfly takes a blood meal from a healthy person.
Symptoms
Some people have a silent infection,
without any symptoms or signs.
But some people have a symptoms..
Cutaneous Leishmaniasis
The main symptom of this condition is
painless skin ulcers. Cutaneous
symptoms may appear only one to two
weeks after the sandfly bite. However,
sometimes symptoms will not appear for
months or years.
Mucocutaneous disease
Symptoms usually appear one to five
years after skin lesions have healed.
These are primarily ulcers in the
mouth and nose or on the lips. Other
symptoms may include:
stuffy or runny nose
nose bleeds
difficulty breathing
Visceral Leishmaniasis
Symptoms often do not appear for months after the bite. Most cases are detected two to six months after infection
Symptoms include:
weight loss
weakness
cough
a fever that lasts for weeks or months
an enlarged spleen
an enlarged liver
decreased production of red blood cells (RBCs)
bleeding
other infections
night sweats
thinning hair
scaly skin or dark ashen skin
Treatment
Some cutaneous infections require no
treatment as lesions may heal within
several months
Systemic therapy with pentavalent
antimonials (sodium stibogluconate or
meglumine antimonate)
Prevention The only way to prevent leishmaniasis is to avoid getting bitten by a
sandfly.
To avoid a sandfly bite, be sure to:
wear clothing that covers as much skin as possible. Long pants, long-sleeved shirts tucked into pants, and high socks are recommended.
use insect repellant on any exposed skin and on the ends of pants and sleeves. The most effective insect repellants contain DEET.
spray indoor sleeping areas with insecticide
sleep on higher floors of a building, since the insects are poor fliers
avoid the outdoors between dusk and dawn—this is when sandfliesare most active
when indoors, use screens and air conditioning
use a bed net tucked into your mattress. Sandflies are much smaller than mosquitos. If possible, spray the net with insecticide containing pyrethroid.
Reducing the size of reservoir host populations ,especially dogs.
THANK YOU! :D