1. بسم الله الرحمن الرحيم

2. Cryptosporidium pravum
Cryptosporidium parvum
Cryptosporidium pravum

3. Cryptosporidiosis zoonosis, cosmopolitan, most human and animals infected by Cryptosporidium parvum
Life cycle
Infective stage :oocyst with 4sporozoites passed in feces.
Upon ingestion sporozoites are released.
Sporozoite penetrate intestinal epithelial cells and undergo two cycle :
1-schizogony gametogony.
Sporulated oocyst ,4-5M (with 4 sporozoites) are passed in feces.

5. duodenal biopsy sample from a patient with AIDS and cryptosporidiosis

6. Pathology & clinical picture:
Immunocopetent persons asymptomatic or mild enterocolitis ,last about 2 weeks.
Immunodeficient persons sever diarrhoea with malabsorption.
Diagnosis & morphology:
duodenal biopsy :gametes or schizont (4-8 merozoites) in epithelial cells.
Stools :oocyst 4-5 m with 4 sporozoites (without sporocyst).

8. Prevention and control:
Treatment
- Self limited in immunocomptant persons ,no effective drugs in cases of AIDS.
- Management of fluid and electrolytes loss.
Prevention and control:
-person-to person or animal to person transmission controlled by sanitation.
-Identify common sources e.g.
contaminated water

9. Toxoplasma gondii

10. Toxoplasma Sporozoite

11. intracellular parasite
Toxoplasma gondii
T. gondii is an obligate
intracellular parasite
life cycle includes both sexual and asexual proliferation and
transmission.
The sexual cycle takes place in the intestinal cells of the cat family.

14. The cat are final hosts for the sexual stages of T. gondii.
After ingestion of tissue cysts, parasites invade the enterocytes, undergo several division (asexually) and differentiate into gametocytes.
The gametocytes form a zygote or ‘oocyst’ that is shed into the environment with the cat’s faeces.
The oocyst takes 1 to 5 days after excretion to sporulate (become infective). 

15. The oocyst with (8) of highly infectious ‘sporozoites’ may persist for years in a moist environment.
Sporulated oocyst resist disinfectants, freezing, and drying, killed by heating (70°C for 10 minutes).
After ingestion by a mouse the sporozoites differentiate to the rapidly dividing ‘tachyzoite’ which
begins the acute infection.

17. Sporulated oocyst unsporulated oocyst

18. A) ingestion of undercooked infected meat containing cysts .
Human infection
A) ingestion of undercooked infected meat containing cysts .
B) ingestion of the oocyst from
contaminated hands or
food (CAT`s feces)
C) organ transplantation or blood
transfusion;
D) transplacental (congenital)
E) accidental inoculation of
tachyzoites.

19. Toxoplasma cysts are found in skeletal muscle, myocardium, and brain; these cysts may remain throughout the life of the host

20. a cyst occupying the whole cell (psuedocyst).
CYCLE IN INTERMEDIAT HOST
(MAN)
Sporozoites released from the oocyst penetrate the intestinal mucosa and find their way into macrophages divide very rapidly (named tachyzoites) and form
a cyst occupying the whole cell
(psuedocyst).

21. containing tachyzoites)
blood macrophage (Pseudocyst
containing tachyzoites)

22. The infected cells burst and release the tachyzoites to enter another cells, including muscle and nerve cells, and multiply slowly (bradyzoites).
These cysts are infectious to carnivores (including man).
man is a dead-end host.

23. Toxoplasma cyst in brain tissue (Bradyzoites)

24. Pathogenesis
Host cells are destroyed by active multiplication of parasites producing necrotic foci.
Congenital infection often involves the retina and brain; focal chorioretinitis result in impaired vision.

25. Brain involvement in immuno-suppressed patients may lead to large necrotic abscesses.
Disease reactivation in immuno-suppressed patients may result from the rupture of a tissue cyst.

26. During the acute infection, congenital transmission to fetus can occur.
Latent bradyzoite (tissue cysts) persist for the life of the host,can re-emerging,but do not produce overt disease in healthy individuals.
Carnivorous ingestion of tissue cysts can infect a naive host, lead to nonsexual propagation.
In the cat, this will initiate the
sexual cycle.

27. Pathogenesis of Toxoplasmosis
Chronic Bradyzoites (Cysts) I M U N T Y
acute Tachyzoites
Cell invasion
cell necrosis
calcification

28. Symptoms
Toxoplasma infection is common, but rarely produces symptoms in normal individuals.
In immunocompetent adults, it may produce flu-like symptoms, sometimes lymphadenopathy.
In immunocompromised it results in generalized parasitemia in brain, liver lung and other organs, and often death.

29. Intrauterine infection
asymptomatic
Adult infection mild
symptomatic
severe
mild
Intrauterine infection
Fever, pneumonia, hydrocephalus, microcephaly, encephalomyelitis

30. Congenital infections occur in about 1-5 per 1000 pregnancies of which:
5-10% result in miscarriage,
8-10% result in serious brain and eye damage to the fetus,
10-13% of the babies will have visual handicaps.
Although 58-70% of infected women will give a normal birth, a small proportion of babies will develop active retino-choroiditis or mental retardation in childhood or young adulthood.

37. Laboratory Diagnosis Sabin Feldman dye test
It is sensitive but requires use of live toxoplasms ,not widely used.
In acute infection diagnosis confirmed by identifying toxoplasms in stained preparations of:
Lymph node aspirates, CSF, peritoneal aspirate, bone marrow or, plural fluids …

38. Mouse inoculation by biopsy and follow up for mouse to isolate organism or demonstrate seropositivity.
Detection of parasitic genetic material by PCR, especially in detecting congenital infections in utero.

39. Detect IgM and IgG antibody
Laboratory Diagnosis
Detect IgM and IgG antibody
Serologic test is the routine method of diagnosis.
High antibody titer particularly of IgM + raising titer of IgG, must be considered in relation to clinical finding ,
but interpretation of result is difficult because high antibody found in nearly all population due
to subclinical infection.

42. Treatment:
Acute infections benefit from pyrimethamine or sulphadiazine. Spiramycin is a successful alternative.
Pregnant women are advised to avoid cat litter, carefully handling uncooked and undercooked meat.

43. الحمد لله