2. Introduction
A protozoan parasite of avian
erythrocytes transmitted by the
'blackfly' Simulium spp.
 Infection causes the disease

leucocytozoonosis.
 The
parasites were first seen by
Danilewsky in 1884 in blood from an
owl.
 There are over 100 species in this genus.

3. Scientific Classification
Kingdom
Chromalveolata
Phylum
Apicomplexia
Class
Aconoidasida
Order
Achromatorida
Family
Leucocytozoidae
Genus
Leucocytozoon
Species
Andrewsi, Simondi

4. Major Species
There are over 100 species in this
genus, but the 3 most important species
that’ve infected the most common
domestic birds are;
 Leucocytozoon caulleryi(chickens)
 Leucocytozoon smithi(turkeys)
 Leucocytozoon simondi(ducks and
geese)


5. Geographical Distribution

In Thailand, India, Taiwan, Japan, Burma, Sri
Lanka, the Philippines, Singapore, Malaysia,
Indonesia, China, and Korea, USA, Canada
and Africa most cases have been reported.
 Acute
outbreaks of leucocytozoonosis have
been reported in chickens, turkeys,
waterfowl and wild birds worldwide.

6. Hosts & Vectors
Definitive host
Ducks
 Turkey
 Geese
 Swans
 Similar waterfowl and Chickens

Vector
Black Fly(Simulium spp)

7. Leucocytozoon use Black flies (Simulium
species) as their intermediate host and
Birds as their definitive host.
 Over 100 species of birds have been recorded
as hosts to these parasites.
 Leucocytozoon does not threaten human
populations in terms of potential infection,
infected poultry is not pathogenic in humans.
 Still, the parasite's economic impact could hurt
poultry farmers' revenue as mortality rates are
extremely high, especially among young birds


8. Transmission in Host
Leucocytozoon's involves an
intermediate host (the blackfly) which
carries the parasite from one avian host
to another.
 When the blackfly vector bites a bird,
perhaps around the unfeathered eye
area, sporozoites are released in the
vector's saliva and into the bird's

circulatory system.

10. Life Cycle
It completes it’s life cycle in Two
different hosts i;e Intermediate
host(black fly) and Definitive host(birds)
 In Black fly, it enters in it’s body when
the fly feeds on the bird already been
infected by the parasite.
 After penetrating in the fly it’s
gametophytes get mature and
reproduce in Midgut.


11. In the insect vector these elongated
gametocytes become either a female
(macro)gametocyte with a red-staining
nucleus
 Male (micro)gametocyte with a palestaining diffuse nucleus, which come
together to form an ookinete.
 This ookinete invades an intestinal cell
of the fly vector, where it matures into an
oocyst.
 This oocyst produces sporozoites which
migrate to the salivary glands of the
blackfly, thus reinitiating the cycle.


12. In Birds, sporozoites invade the liver cells
and develop into small schizonts, which in
turn produce merozoites.
 Schizonts release merozoites or secondary
schizonts in the endothelial cells of the blood
vessels and in essentially any of the viscera.
 The merozoites either enter red blood cells or
macrophages.
 In the red blood cells, merozoites develop into
round gametocytes.
 In the macrophage, merozoites develop into
megaloschizonts, which then divide into primary
cytomeres.


14. Pathogenesis

Five days post infection:
 Many schizonts develop in hepatocytes
 Cells rupture

Seven days post infection:
 Megaloschizonts begin to appear in spleen
 Also appear in Lymph and other tissues
 Gametocytes accumulate in liver

12+ days post infection
 Hemorrhagic scars from rupturing
megaloschizonts

15. Area of Infection

Leucocytozoon’s infect the
 Heart
 Liver
 Lungs
 Spleen
 Brain

16. Diagnosis
A diagnosis can be made by
 The demonstration of gametocytes in blood
smears.
 Histopathological examination of the liver,
spleen and brain can show developing
megaloschizonts.
 Necropsy may reveal an enlarged spleen and
liver.
 Since the majority of birds are sub clinically
infected with Leucocytozoon, other causes of
death must be ruled out even with the presence of
Leucocytozoon gametocytes in peripheral blood
smears.

18. Clinical signs/symptoms
The majority of birds affected with
leucocytozoonosis exhibit no clinical
signs.
 Visibly affected show mild to severe
signs of anorexia, luekocytosis,
weakness, anemia, emaciation, and
have difficult breathing.
 Young birds manifest in appetence,
weakness, dyspnea, and sometimes
death within 24hrs.


19.  Signs
in adults appear less abruptly and
consist of listlessness and a low
mortality rate.
 The mortality in adult birds occurs as a
result of debilitation and increased
susceptibility to secondary infection.
 Granulomatous and lymphocytic lesions are
seen in the lungs, heart, brain and
peripheral nerves. Large gametocytes can
block capillaries of the lungs.

20. Spleen
Lungs
Leucocytozoon in
leucocytes

21. Treatment and Control
Treatment usually is not effective,
control of the Leucocytozoon in
domestic avian species has, until
recently, been limited to control of the
blackfly vector.
 Preventive medication using
Pyrimethamine(1 ppm) and
Sulfadimethoxine(10 ppm) combined in
the feed controls it.


22.  Clopidol (0.0125%–0.025%)
controls invertebrate vectors are helpful.
 Quinacrine
hydrochloride or
Trimethoprim/Sulfamethoxazole solution
have been used i;e parasitemia is
reduced, but the infection is not cleared.
 Oral Anti-LEUCOCYTOZOONOSIS
Vaccines based on TRANSGENIC plants.

23. Hepatozoon

24. Introduction
 Hepatozoon is
a protozoan parasite of
peripheral blood neutrophils.
 It’s genus Apicomplexan protozoa which
incorporates over 300 species obligate
intra erythrocytic parasites.
 Infection caused by hepatozoon is called
Hepatozoonosis.
 A Hepatozoon parasite was initially
reported from a cat in India in 1908.

25. Scientific Classification
Kingdom
Chromalveolata
Phylum
Apicomplexia
Class
Conoidasida
Order
Eucoccidiorida
Family
Hepatozoidae
Genus
Hepatozoon
Species
Hepatozoon canis.


26. Geographical Distribution
 It’s
widely distributed in the world
mainly found in;
 Africa
 Southwestern Asia
 Southwestern
 Eastern Europe
 North and South America.
 Brazil
 United States

27. Hosts and Vectors
 Dogs
 Cats
 Rabbits
 Rats
 Snakes
 And
other domestic animals
Vectors
Ticks

28. Major Species
Hepatozoon has more than 300 species but
the most imp. Of them which cause infection
is;
 Hepatozoon canis.(dogs, jackals and all
canines)
 Hepatozoon atticorae(birds)
 And very recently discovered
Hepatozoon sipedon.(infect Snakes and
mosquitoes)


29. Transmission in Host

Transmission of the infection occurs via
ingestion of infected ticks.

Dogs are infected by ingesting infected
ticks during grooming behavior or eating
prey that has attached ticks.
It’s not transmitted by Tick biting.
 In Snakes, it is transmitted through
infected mosquitoes that are ingested
by some frogs that later on, eaten by the
snake transmitting it.
 Mosquitoes get infected by feeding on
infected snakes.


31. Life Cycle
Members of the genus Hepatozoon possess
particularly complex life cycles which vary
considerably among species.
 Sexual reproduction and sporogenic
development occur in haemocoel of the
invertebrate host.
 It also has two hosts;
Intermediate(ticks)&Definitive(Dogs/snakes)


32. Vertebrate host, consumes the infected
invertebrate.
 The sporozoites then migrate to the liver of
the vertebrate, where they undergo multiple
fission (asexual reproduction) to produce
merozoites.
 Merozoites are released into the bloodstream
where they form gametocytes.
 Gamonts are large, conspicuous organisms
which occupy significant portion of
the erythrocyte, and are easily visible on
simple blood films.


33. The invertebrate vector feeds on the blood
of the infected vertebrate
 The gamonts are taken up into the gut once
more, where they undergo gametogenesis
and the cycle begins once more.
 In case of snakes, they do not typically
feed on mosquitoes, a third, intermediate
host is required, in this case a frog.
 The frog ingests the infected mosquito, and
the snake acquires the infection by feeding
on the now infected frog.
 Another mosquito can then feed on the
snake, thus continuing the life cycle.


35. Diagnosis
Is based on,
 Blood
tests
 Clinical signs
 Biopsy of skeletal muscles
 Serological tests
 Molecular diagnosis

36. Clinical Signs & Symptoms
 Periodic
or persistent fever
 Weakness muscle atrophy
 Generalized pain
 Stiff gait and hind limb paralysis.
 Pus-filled eye discharge.

37. Treatment & Control
The current therapy for hepatozoonosis
includes;
 Trimethoprim
 Sulfadiazine
 Clindamycin
 Pyrimethamine (TCP) drugs for two
weeks to destroy the parasites.

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