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