1. PHYLUM
NOW KNOWN AS
Presented by:
Raissa Tutanes Guldam
BSMT-IV

2. Objectives:
At the end of the lecture, you should be able to at
least learn the:
Parasite Biology
Pathogenesis and Clinical
Manifestations
Diagnosis
Treatment
Prevention & Control

3. SPOROZOANS
 Sarcocystis spp. (hominis, suihominis &
lindemanni)
 Cryptosporidia spp. (parvum)
 Eimeria spp.
 Isospora spp. (hominis & belli)
 Plasmodium spp. ( falciparum, vivax, malariae &
ovale)
 Toxoplasma gondii

4. SPOROZOANS (contd.)
*General Characteristics*
 Tissue parasites
 Obligate parasites
 Have no definite organelle for locomotion
 Have complex life cycle with alternating sexual
and asexual generations
 Asexual – schizogony – schizogonic cycle
 Sexual – sporogony – sporogonic cycle
 Female – macrogametes
 Male - microgametes

5. A. SARCOCYSTIS SPP.
S. HOMINIS, S. SUIHOMINIS, &
S. LINDEMANNI

6. General Characteristics
 Infect humans (DH) and animals (IH)
 Sarcosporidiosis or sarcocystosis - infection
 Spread throughout various organs and tissues
 MOT – ingestion of uncooked or undercooked
meat containing the SARCOCYSTS
 Infective Stage: Human – SARCOCYSTS
 IH - SPOROCYSTS

7. Parasite Biology
 Zoite – simplest form
 Banana-shaped cell
 Pointed end – equipped for entering the host cells
 Sporocyst = 4 zoites  sporozoites
 Sarcocyst = formed from sporozoites
 Asexual cycle – occurs in IH
 Sexual cycle – occurs in DH

9. Parasite Biology (contd.)
S. hominis S. suihominis
IH cattle swine
DH human human
Sporocyst bigger smaller
Effect Intestinal Intestinal
sarcocystosis sarcocystosis

10. Sarcocystis
hominis

11. Pathology & Clinical Manifestation
 Gastroenteritis with diarrhea
 Eosinophilic enteritis
 Myalgia
 Weakness
 Mild increase of creatine kinase

12. Diagnosis
 Fecal flotation method – sporocysts
 9-16um in length
 Oblong or cylindrical
 4 long teardrop-shaped sporozoites
 Western blot
 IFA and ELISA

13. Treatment & Prevention
 No effective treatment is known
 Corticosteroid – treat muscular inflammation
 Trimethoprim-sulfamethoxazole – treat
intestinal infections
 “Cook the meat well before eating!!!”

14. B. CRYPTOSPORIDIA SPP.
C. PARVUM
C. HOMINIS

15. Parasite Biology
 Cryptosporidiosis – infection
 Causes severe diarrhea (immunocompromised)
and transient diarrhea (healthy persons)
 Water-borne transmission – is the most
common source of this infection
 MOT: ingestion of oocysts
 IS: oocysts containing sporozoites
 1 oocyst = 4 sporozoites
 Oocyst = 4 to 5 um
Watch this!

17. Pathogenesis & Clinical Manifestations
 Self-limiting diarrhea
 Abdominal pain
 Anorexia
 Fever
 Weight loss

18. Diagnosis
 Intestinal biopsy – identification of organism
 Duodenal string test (Enterotest) – to recover
oocysts
 Zinc Sulfate Centrifugal Flotation Technique
 Sheather’s Sugar Flotation Procedure
 Formalin-Ethyl Acetate Sedimentation
 Acid-fast Stain – red-pink doughnut-shaped
circular in blue background (quickest and
cheapest method)

19. Cryptosporidia spp.

20. Treatment & Prevention
 Nitazoxanide – effective
 Paromomycin treat
 Clarithromycin diarrhea
 Azithromycin
 Spiramycin
 “Multiple disinfectant & water treatment
process”

21. C. Toxoplasma gondii
A PARASITE OF COSMOPOLITAN
DISTRIBUTION

22. General Characteristics
 House Cat – definitive host
 MOT – consumption or handling of infected
meat or from contact with cat feces
 IS – oocysts
 Cysts – found in muscles and CNS
Watch the video here I’m cute but
deadly!!!

24. Parasite Biology
 Oocyst = 2 sporocysts, each encloses
4 sporozoites
(passed in the feces)
 Similarin appearance to those
of Isospora belli but smaller
 Trophozoites – found in the mesenteric lymph nodes
and other organs of the cat
 Tachyzoites – multiply quickly and spread the infection
 Bradyzoites – slow-developing and form cysts

25. Toxoplasma
gondii

26. Pathogenesis & Clinical Manifestations
 Toxoplasmosis – commonly asymptomatic
 Cysts – can be found in the brain, skeletal and heart
muscles, and retina
 Encephalitis, myocarditis & focal pneumonia –
immunocompromised
 Stillbirth & abortion – 1st trimester of pregnancy
 Congenital toxoplasmosis

27. Diagnosis
 Examination of tissue imprints stained with Giemsa
 Sabin-Feldman methylene blue dye test –
detect Ab against T. gondii
 Biopsy
 PCR
 ELISA
 Latex Agglutination Test

28. Treatment & Prevention
 Pyrimethamine + sulfadiazine – for 1 month
-To keep under control but do not kill it
 Cook food well
 Pregnant women should avoid contact with cats
 Avoid unpasteurized milk

29. D. EIMERIA SPP.
RESPONSIBLE FOR THE POULTRY DISEASE
COCCIDIOSIS

30. General Characteristics
 4 sporocysts , each containing 2 sporozoites
 Causes bloody diarrhea
 E. tenella
 E. maxima
 E. necatrix
 E. fraterculae

31. Eimeria spp.

32. E. ISOSPORA SPP.
ISOSPORA HOMINIS
ISOSPORA BELLI
ISOSPORIASIS

33. Isospora hominis
 Host: men
 Vector: Dog
 MOT: Ingestion of mature oocyst
 Symptoms:
 Stomach pain
 Diarrhea
 Steatorrhea
 Anorexia
 Fever

34. General Characteristics
I. hominis I. belli
Other name Cytospermium hominis Cytospermium
intestinalis
Oocyst shape Oblong papaya
Layer Double-layer One layer
Presence of microphyle yes no
sporocysts 2 2
sporozoites 4 4
Host Men Men
MOT Ingestion of oocyst Ingestion of oocyst

35. Isospora
spp.

36. F. PLASMODIA SPP.
THE GENUS THAT CAUSES
MALARIA

37. MALARIA
 Is still considered the most important parasitic
disease affecting man, responsible for 1.5 to 2.7
million deaths annually
 One of the three major infectious disease threats,
along with HIV and tuberculosis (WHO)
 Transmitted by the bite of an infected female
Anopheles mosquito
 A protozoan disease caused by members of the
genus Plasmodium characterized by recurring
fever, chills and sweats.

38. MALARIA (contd.)
 P. falciparum responsible for over 90%
 P. vivax of all the cases of human malaria
 P. ovale
 P. malariae
 Pigment producers – malarial parasites feed on
Hgb
 Ameboid in shape

39. Parasite Biology
Asexual Cycle Sexual Cycle
Human (IH) Anopheles mosquito (DH)
Schizogony  merozoites Sporogony  sporozoites
Gametogony  gametocytes
MOT: bite of vectors & blood transfusion

40. Parasite Biology (contd.)
• life cycles of all four human species of malaria are
similar
• sporozoites – infective stage to human
• Injected to human and carried to the liver
• Merozoites – enter the rbc
 - Develop into microgametocytes (male) and
macrogametocytes (female) which are picked up by the
mosquito for completion of the cycle
• Hypnozoites – produced by P. vivax and P. ovale ;
resting stage
• Trophozoites – developed in the rbc

41. Exo-erythrocytic Stage
 sporozoites
enters hepatocytes of liver
 schizonts
dividing forms of liver stages
 merozoites
are released by hepatocytes
 hypnozoites
resting liver stages

42. Blood Stages
 merozoites
enter erythrocytes
 trophozoites
feeding and growing stages
in red cells
 schizonts
multinuclear stages
in red cells
 gametocytes
sexual blood stages

43. 1. early trophozoite
2. early trophozoite (double infection)
3. early trophozoite double chromatin with a few Maurer's dots
4. late throphozoite with Maurer's dots and crenated red cell
5. Mature schizont with merozoites and clumped pigment
6. macrogametocyte with bluish cytoplasm and compact chromatin
7. microgametocyte with pinkish cytoplasm and dispersed
chromatin.
Watch the life cycle

45. Pathogenesis & Clinical Manifestations
P. P.vivax P. ovale P. malariae
falciparum
Other name Malignant Benign tertian Ovale malaria Quartan
tertian or malaria malaria
subtertian
malaria
Pre-patent 11-14 days 11-15 days 14-26 days 3-4 weeks
period
Incubation 8-15 days 12-20 days 11-16 days 18-40 days
period
Erythrocytic 48 hours 48 hours 48 hours 72 hours
Cycle
Chromatin Maurer’s Schuffner’s Schuffner’s Zieman’s
dots (coarse red (fine red
granules) granules)

46. P. P.vivax P. ovale P. malariae
falciparum
trophozoite Ring & comma Signet-ring Ring to Band form
forms shape rounded
gametocytes Banana- Oval Round Round
shaped
Merozoites 8-40 12-24 14-16 6-12
Schizont Single dark Loose mass Concentrated concentrated
pigment mass mass

47. Pathogenesis & Clinical Manifestations (contd.)
 Regular Paroxysms of fever with asymptomatic
intervals
 Prodromal symptoms
 Weakness and exhaustion
 Desire to stretch and yawn
 Aching bones, limbs and back
 Loss of appetite
 Nausea and vomiting
 Sense of chilliness
 Malaise
 Diarrhea
 Epigastric discomfort

48. 3 Stages of Classical Malaria Paroxysm
 Cold Stage  Pressure goes down
 Chilling  Intense headache
 Loss of appetite  Dry skin which lasts for 2-4 hours
 Goose flesh
 Convulsion of children which  Sweating Stage
lasts for 1-2 hours  Profuse sweating
 Temp. Is going up  Gradually, temp. Goes down
 Less intense headache which lasts
 Hot Stage for 2-5 hours
 Sensation of great heat  Patient feels exhausted until falls
 Restlessness asleep
 Pulse is full and pounding
 Vomiting

49. Diagnosis
 Thick and thin blood smears – “gold standard”
 Quantitative Buffy Coat (QBC) Method – screening
 RDT = Immunochromatographic Methods – detect
Plasmodium Ag
 Serologic Tests – IHA, IFAT, ELISA and PCR

50. Diagnostic Points
1. Red Cells are not
enlarged.
2. Rings appear fine and
delicate and there may be
several in one cell.
3. Some rings may have two
chromatin dots.
4. Presence of marginal or
applique forms.
5. It is unusual to see
developing forms in
peripheral blood films.
6. Gametocytes have a
characteristic crescent
shape appearance.
However, they do not
usually appear in the blood
for the first four weeks of
infection.
7. Maurer's dots may be
present.

51. Diagnostic Points
1. Red cells containing
parasites are
usually enlarged.
2. Schuffner's dots are
frequently present in
the red cells as shown
above.
3. The mature ring
forms tend to be large
and coarse.
4. Developing forms
are frequently
present.

52. Diagnostic Points
1. Ring forms may have a squarish appearance.
2. Band forms are a characteristic of this species.
3. Mature schizonts may have a typical daisy head appearance with up to ten merozoites.
4. Red cells are not enlarged.
5. Chromatin dot may be on the inner surface of the ring.

53. Diagnostic
Points
1. Red cells
enlarged.
2.Comet forms
common (top
right).
3. Rings large
and coarse.
4. Schuffner's
dots, when
present, may be
prominent.
5. Mature
schizonts similar
to those of P.
malariae but
larger and more
coarse

54. Treatment & Prevention
 Chloroquine – treatment of choice
 Sulfadoxine-pyrimethamine or quinine – alternative
for chloroquine-resistant
 Artemisinin and derivatives
 Use mosquito nets
 Use insect repellants
 Wear light-colored clothing

55. Thanks for listening! 
ANY QUESTION?