2. classification of Leishmania
• The leishmaniases include a complex of vector-borne diseases,
caused by more than 20 species of the protozoan genus Leishmania,
and ranging from localized skin ulcers to lethal systemic disease.
Leishmaniasis is classified as one of the "most neglected diseases,"
based on the limited resources invested in diagnosis, treatment and
control, and its strong association with poverty.
3. Phlebotomine Sand Flies…
Order: Diptera
Family: Psychodidae
Genera:
● New World ● Lutzomyia
● Brumptomyia
● Warileia
● Old World ● Phlebotomus
● Sergentomyia
(Aranasy et al., 1999 and Martin-Sanchez et al., 2000)
4. Morphology
• Adults - small (less than 5 mm long) with
conspicuous black eyes, long narrowly obovate
wings that form a V-shaped out line above thorax,
wing veins are parallel to each other ,slender with
piercing mouthparts and long antennae; There are
fine hairs on body, wings and legs.
10. Habits
• Only female sandflies are blood sucker and they are
nocturnal feeders.
• They are poor flier and fly in a characteristic hopping,
30-1000 m, not over 200 m.
• Prevalent from May to September. Larvae survive
through the winter.
11. Hematophagous diptera(flies) are of two basic types :-
Capillary feeders : mouth parts are inserted into the skin and
blood is withdrawn directly (solenophages) .
Pool feeders : mouthparts short and are used to lacerate the
skin then the blood flow and ingested by the fly (temophages).
12. Female feed on blood at night.
Sand flies are pool feeder ( telmophages ) which suck blood
from a small wound they make in the skin.
Their bite is therefore relatively painful .
13. - Sand flies do not produce a buzzing or whining noise before
biting which again reduces the perceived nuisance to man.
-Color of sand flies are brownish in day light , but their
bodies
are densely covered in oily hairs which give them whitish
appearance when illuminated
17. Life cycle (stages)
• Eggs are laid in dark humid animal burrows, cracks
or crevices, or under dead leaves (Egg laid on moist
dark place containing organic debris ( under leaves
on the ground ,in damp mossy place ,in rank
vegetation or on hallow tree trunks ) .
• There are 4 larval instars, the larval stage lasting a
total of 4-6 weeks
• The pupa requires 10 days for development
• LC requires 40-50 days
• Only adult females suck blood
• Adult life span 2-3 weeks, 30-50 eggs/female.
19. - Sand fly bite: The bite in indudurated, inflamed with a
wheal of 1-2 cm. and accompanied by pruritus lasting for
hours or weeks and sometime with systemic allergic reaction
(fever, nausea, malaise swelling of the bitten member).
- Treatment: Topical application of phenolated camphor in
mineral oil or anesthetic ointment.
20. 1. Leishmaniasis is transmitted by the bite of female
phlebotomine sandflies. The sandflies inject the infective
stage, promastigotes, during blood meals.
2. Promastigotes that reach the puncture wound are
phagocytized by macrophages.
3.They transform into amastigotes.
4. Amastigotes multiply in infected cells and affect different
tissues.
5. Sandflies become infected during blood meals on an
infected host when they ingest macrophages infected with
amastigotes.
6. In the sandfly's midgut, the parasites differentiate into
promastigotes.
7. They multiply and migrate to the proboscis.
24. inoculation
ingestion
Sand fly
Vertebrate host
Transformation
Attachment and
phagocytosis
Multiplication and
reinfection
Release from macrophages
Multiplication
Transformation
Protozoan parasites (proto = first; zoan = animal)
Small (usually microscopic) single-celled organisms
Life cycle can be divided into 2 stages depending on the host:
Sand fly vector = Leishmania promastigotes
Human or other vertebrate = Leishmania amastigotes
Leishmania fact sheet
What are Leishmania parasites?
Life cycle of Leishmania parasites
Form of Leishmania within human or other vertebrate host’s cells (have
resorbed their flagellum)
Size: 2-6 mm
Shape: ovoid
Characteristics: central nucleus
Leishmania amastigotes
Different parasites cause different forms of the disease
Flagellum
Form of Leishmania within sand fly vector:
• Can move in the direction of their flagellum
• Can be cultured
Leishmania promastigotes
Amastigotes
Promastigotes
Cutaneous lesihmaniasis Visceral lesihmaniasis
25. EARLY DIAGNOSIS
• L.D BODIES (SPLEEN, BONE MARROW, LYMPH NODE)
• ALDEHYDE TEST
• ELISA & Polymerize chain reaction (PCR)
26. Control
• 1. Elimination of breeding grounds
• 2. Application of insecticides.
• 3. Personal protection. المكافحة
:
•
الحوائط في والثقوب الشقوق سد
•
النوافذ على الشبك إستخدام
•
الذباب طاردات إستخدام
•
الحشرية المبيدات إستخدام