2. CLASS- ZOOMASTIGOPHERA
The parasites belonging to this group of protozoa possess one or more flagella giving them the power of motility.

3. FLAGELLATES
These are classified according to their habitat into TWO groups:
1.Intestinal,oral & genital flagellates.
2.Blood & tissue flagllates.

4. Giardia intestinalis =(lamblia)
Giardiasis
Giardia intestinalis =(lamblia)
Class Zoomastigophorea
Order Diplomonadida
Family Hexamitidae

5. Giardia lamblia (intestinalis, duodenalis) - humans, mammals
Giardia muris - mammals
Giardia ardeae - birds
Giardia psittaci - birds
Giardia agilis - amphibians

6. Habitat
Duodenum and the upper part of the jejunum of the man.

7. Morphology
Exits in two phases:
A) Trophozoite
B) Cyst

8. TROPHOZITE
When viewed flat,the shape of the trophozoite is like that of badminton racket.
The dorsal surface is convex & the ventral surface is concave like a sucking disc.
The size of the trophpzoite is 14 micrometer long & 7 micrometer broad.
All organs of the body are paired.
There are 2 axostyles,2 nuclei and 4 pairs of flagella.

9. CYST
It is oval in shape and measures 12 micrometer long and 7 micrometers in breadth.
Giardia intestinalis

10. Epidemiology Presumed to be zoonotic, but new evidence indicates that
strains may be species specific.
Host can be humans, primates, cats, dogs, calves,
beavers, rabbits, etc.
World wide distribution
Highest incidence in children, young adults in late summer.

11. Transmission Person to person transmission
Water sports, surface contamination, watershed contamination
Sexually active male homosexuals and persons in custodial institutions.

14. PATHOGENICITY
With the help of the sucking disc the parasites attach itself on the epithelial cells of the intestine and may cause disturbance, leading to malabsorption of fat.
The patient may complain of persistent looseness of bowels , and mild steatorrhoea.

15. Pathogenesis and Immune response
The production of diarrhea, and occasionally malabsorption, is the result of a complex interaction of Giardia with the host,
Infection occurs after oral ingestion of as few as 10 to 25 cysts.
After excystation, trophozoites colonize and multiply in the upper small bowel
Adherence of G. lamblia in the human gut may be via the disk,
but may also involve specific receptor-ligand interactions

16. Pathogenesis and Immune response
Several pathogenic mechanisms have been postulated
Disruption of the brush border
Mucosal invasion
Elaboration of an enterotoxin
Stimulation of an inflammatory infiltration leading to fluid and electrolyte secretion and occasionally to villous changes

17. Giardia Lamblia clinging to the wall of a duodenal villus.
Source: Gallery of histology Woods and Ellis2000
Giardia Lamblia clinging to the wall of a duodenal villus.

18. Immune Response Partially protective immunity may develop to Giardia
Immune response involves both cellular and humoral immunity
Ig A, serum Ig G and Ig M are detected in patients: Role of Ig A
is not completely understood, probably inhibits trophozoite attachment
IgA deficiency lead to chronic giardiasis
Cell mediated immune response may also play a role
Human milk may also play a role in protection of the host against Giardia : Free fatty acids and IgA antibodies

19. Infection with G. lamblia includes
Asymptomatic cyst passage (5 to 15% )
Acute self-limited diarrhea (25 to 50% )
Chronic syndrome of diarrhea, malabsorption and weight loss
Symptomatic giardiasis is characterized by (Travelers Diarrhea)
Acute onset of diarrhea
Abdominal cramps, bloating, and flatulence
Malaise, nausea, and anorexia
May complain of sulfuric belching
Vomiting, fever, and tenesmus occur less commonly.
Stools may be profuse and watery, but later they are commonly greasy, and foul-smelling.

20. Diagnosis
Giardia should be identified 50 to 70% of the time after one stool, and 90% identification after three stools
Wet, saline mounts: falling leaf motion, fibrils present, and nucleic characteristics.
Biopsy tissue/duodenal aspirate /Enterotest stained by trichrome or Giemsa stain. 
Enzyme immunoassay and fluorescent monoclonal antibody antigen detection systems
Sensitivity & specificity: %
( ProSpec T, GiardEIA, MeriFluor, Color Vue, and DD System)

21. Drug Adult Pediatric
Metronidazole 250mgtidX 5-7 d 5mg/kg/tid x 7 d
Quinacrine 100mgtidX5-7d 2mg/kg tidX7d
Furazolidone mg qid × 7–10 d 2 mg/kg qid × 10
Paromomycin 25–30 mg/kg/d in 3 doses × 5–10 d
Tinidazole 2 g × 1 dose

22. PREVENTION
The prevention of giardiasis requires proper handling and treatment of water
Good personal hygiene on an individual basis
Chlorination alone is sufficient to kill G. lamblia cysts, important variables, such as water temperature, clarity, pH, and contact time, alter the efficacy of chlorine, and higher chlorine levels (4 to 6 mg/liter) may be required.
Bringing water to a boil is sufficient to kill all protozoal cysts; at high altitudes, boiling for longer periods may be necessary

23. Cryptosporidium, Cyclospora, and Isospora
Secretory diarrhea without RBC or WBC in the stool.
None are easily found in routine “stool for ova and
parasites.”
Modified acid-fast staining is
useful for all of the Coccidians.
Isospora belli Cyclospora Cryptosporidium
CDC

24. COCCIDIA Thick-walled oocysts excreted in feces In Humans
Cryptosporidium
Cyclospora
Isospora
Sarcocystis
Toxoplasma

25. Classification Kingdom : Animalia Sub kingdom : Protozoa
Phylum : Apicomplexa
Class : Sporozoa
Sub class : Coccidia
Order : Eucoccidia
Sub order : Eimeriidae
Family: Eimeriidae

26. Cryptosporidium parvum
History :
Tyzzer st reported by in gastric crypts of laboratory mouse
1971-C.parvum as pathogenic causing micro organism.
1976-1st case of human infection of diarrhea
1993-Massive outbreak of cryptosporidiosis in Milkwaukee affected 4,00,000 people

27. Species of Cryptosporidium
C. parvum
C. hominis (previously C. parvum genotype 1)
C. canis,
C. felis,
C. muris

28. Habitat of C.parvum In the form of trophozoite.
It is present in the intestinal epithelial cell.
Remaining just within brush border.

30. Trophozoite Measures 1micro meter in diameter.
They are found on brush border (micro villous surface) of small intestine.
They grow into schizonts.

31. OOCYST These oocyts are either: 1.Thickwalled-80% passed in feces
2. Thin walled -20% excyst endogenously causing internal autoinfection
Oocyst contain 4 sporozoites. NO SPOROCYSTS PRESENT
Size µm
THICKWALLED OOCYST
THIN WALLED OOCYST

32. Modes of infection Reservoir host- Live stock, cats, dogs, birds etc.
Portal of entry- occurs by ingestion of oocysts usually with
contaminated water
fecal-oral and
anal oral transmission from person to person
Susceptibility- Veterinary personnel animal handlers are at high risk

33. Transmission
The 50% infective dose (ID50) of C. parvum is only 132 oocysts for healthy persons with no previous serological immunity to cryptosporidiosis

34. Outbreaks result from drinking water of surface water sources -lakes and rivers .
Swimming pools and water park wave pools
Also, untreated groundwater or well water public drinking water supplies.
The highly environmentally resistant cyst of C. parvum survive various drinking water filtrations and chemical treatments such as chlorination.
Food can be contaminated by either an infected person or an asymptomatic carrier . The oocysts do not survive cooking, but food contamination can occur

35. Person-person transmission
Day-care centers, where infants or younger children are clustered within classrooms, share toilets and common play areas
Day-care employees through careless diaper-changing or through washing the laundry of infected children.
Nosocomial settings
Aerosol infection is fairly likely, since Cryptosporidium oocysts are shed in large numbers during acute infection and are immediately infective to others

36. Persons most likely to be infected by Cryptosporidium are:
Infants and younger children in day-care centers
Those whose drinking water is unfiltered and untreated
Involved in farming practices such as lambing, calving, and muck-spreading
Engaging in sexual practices that brings a person into oral contact with feces of an infected individual
Patients in a nosocomial setting with other infected patients or health-care employees
Veterinarians who come in contact with farm animals
Travelers to areas with untreated water
Living in densely populated urban areas
Owners of infected household pets (rare)

37. 3)PRESENT IN PARASITOPHOROUS VACUOLE
MONOXENOUS LIFE CYCLE
OF C.parvum
1)INTRA CELLULAR
2)EXTRA CYTOPLASMIC
3)PRESENT IN PARASITOPHOROUS VACUOLE

38. Life cycle of C.parvum(monoxenous)

39. Modes of infection

40. LIFE CYCLE
Large reservoir of wild animals and livestock(Cattles, rodents, puppies, kittens)
Life cycle is completed within a single host
Lacks host specificity-Capable of infecting many different mammalian species
Zoonotic- from animals to humans

41. Life Cycle
Complex -sexual and asexual cycles, and distinct developmental stages
Excystation of the ingested oocyst in the small bowel with release of the four sporozoites
Invasion of intestinal epithelial cells via apical end of the sporozoite within a vacuole formed of both host and parasite membranes and the initiation of the asexual intracellular multiplication stage (parasitophorous vacuole)

42. Differentiation of microgametes and macrogametes
Fertilization - sexual replication
Development of oocysts
Formation of sporozoites within the oocyst, which is then excreted in the stool
The cycle begins anew when these oocysts are ingested by a new host.

43. Pathogenesis
Sporozoite-specific lectin adherence factor has been identified
After sporozoite attachment, epithelial mucosa cells release cytokines that activate resident phagocytes . These activated cells release soluble factors that increase intestinal secretion of water and chloride and also inhibit absorption. They act on various substrates, including enteric nerves and on the epithelial cells themselves
Cell death is a direct result of parasite invasion, multiplication, and extrusion
Cell damage could occur through T cell-mediated inflammation, producing villus atrophy and crypt hyperplasia
Either model produces distortion of villus architecture and is accompanied by nutrient malabsorption and diarrhea

44. Clinical manifestations in immunocompetent
The incubation period - Two days - week.
In immunocompetent patients, it is an acute, yet self-limiting diarrheal illness (1-2 week duration), and symptoms include :
Frequent, watery diarrhea
Nausea
Vomiting
Abdominal cramps
Low-grade fever

45. Immunocompromised persons CD4 counts of <200 cell/cubic mm
The illness is much more severe
Debilitating, cholera-like diarrhea (up to 20 liters/day)
Severe abdominal cramps
Malaise
Low-grade fever
Weight loss
Anorexia

46. Detection and Diagnosis
Stool Conc. Technique:
Sheather’s sugar solution in Zn SO4
Saturated Nacl
Formalin ether conc.
Formalin ethyl acetate
By a biopsy of intestinal tissue . -"patchy" nature of parasitic infection
The modified acid-fast stain is traditionally used to detect –oocysts( um) have sporozoites (dd from Cyclospora-larger and unsporulated) ):

47. 4-5 mm oocysts 4 sporozoites no sporocysts 8-10 mm oocyts 2 sporocysts
Cryptosporidium
4-5 mm oocysts
4 sporozoites
no sporocysts
Cyclospora
8-10 mm oocyts
2 sporocysts
2 sporozoites each
Isospora belli
30 x 12 mm oocyts
4 sporozoites each

48. OTHER DIAGNOSTIC METHODS
Anti-cryptosporidial IgM, IgG, and IgA can be detected by ELISA or by the antibody immunofluorescence assay (IFA), but neither of these assays can provide a direct diagnosis of cryptosporidiosis.
Recently, new genetic methods of detecting C. parvum have been developed, using PCR or other DNA-based detection methods.

49. TREATMENT immunocompetent individuals, general, supportive
Since cryptosporidiosis is a self-limiting illness in
immunocompetent individuals, general, supportive
care is the only treatment for the illness.
Oral or intravenous rehydration and replacement of
electrolytes may be necessary for particularly
voluminous, watery diarrhea.
Antibiotics such as spiramycin and dicalzuril sodium
have produced partial responses in patients. However,
one particular antimicrobial agent, paromomycin, has
shown promise

50. CYCLOSPORA

51. Cyclospora cayetenisis
Cyclospora is associated with diarrhea.
1990- virtually unknown before about
1996 -Contaminated Guatemalan raspberry, cause of a United States outbreak of Cyclospora in.
“yuppie disease” .

52. MORPHOLOGY
OOCYST
DEFINATIVE HOST – REPTILES,BIRDS,
HUMAN BEINGS

53. oocyst 8-10micro meter in diameter
Contains 2 sporocysts each containing 2 sporozoites
Sporozoite contain membrane bound nucleus and micronemes

54. Life cycle of cyclospora
Unsporulated Oocyst
Passed in feces days
Gametogony Oocyst
Sporozoites penetrate epithelium
Producing merozoites
Invade other epithelial cell
mature oocyst(4sporozoites)
Excystation In
small intestine
Human Infection Through
Water(oocyst)

56. Modes of infection
Ingestion of contaminated food with sporulated oocyst.
Contaminated water
Contaminated raspberries.
Contaminated basil leaves.

57. Clinical disease Acute infective diarrhea
Incubation period: 2 to 11 days
Immuno competant individual:
1)Rapid onset of watery diarrhea 7 to 8 stools per day
2)Nausea,anorexia,abdominal cramps
3)Low grade fever and malaise
4)Self limiting remission in 3-4 days followed by relapses from 4-7 weeks
Immuno compromised individual
1)Diarrhea is prolonged 8-7 weeks and severe.
2)Biliary diseases have been reported

59. sporocystic residuum(sr)
Normal light miscroscopy.
Three mature, living oocysts
sporozoites (sp)
sporocystic residuum(sr)
Stieda body (st).
Bar = 10 µm.

60. Direct wet preparation with no staining (x1650).
The outer wall is distinct and thick.
Each body contains several refractive granules.
2 sporocysts in one oocyst

61. Cyclospora cyst taking zeihl neelson staining
                                                                  

62. AUTO FLUORESCENCE
Cyclospora organism flouresce when examined with an UV flourescent microscope.
This factor should be
taken into consideration

63. PREVENTION SEE WHETHER THE RASPBERRY ARE NOT
CONTAMINATED BEFORE YOU EAT
SEE THAT THE WATER IS NOT CONTAMINATED

64. ISOSPORA

65. Isosopora belli Apicomplexa Coccidia Monoxenous life cycle.
Coccida parasites are identified based on the structure of the oocyst.

66. Sporulated oocyst is the infective stage
Invades intestinal epithelial cells
Often asymptomatic
Symptoms mild gastro-intestinal distress to severe dysentery
Often self-limiting, but can become chronic
Symptoms more severe in AIDS patients

67. HABITAT:
Inside human beings.
In form of trophozoites.
Resides in epithelial cell of small Intestine
Here schizogony and sporogony occurs

68. OOCYST Morphology 2 types: Immature oocyst Mature oocyst
DEFINATIVE HOST – HUMAN BEINGS

69. Immature oocyst: Size- 15µm× 20µm Shape – rugby ball
Develop inside epithelial cell of small intestine.
Central individual mass of protoplasm.
They are unsporulated.
They are shed in feces
Immature
oocyst

70. Mature oocyst Size – 20µm × 10µm Shape- rugby shape
It is elongated and narrow at one pole with neck like restricted area.
2 sporocyst with 4 sporozoites each
Mature
oocyst

71. Modes of infection Reservoir host: NIL
Source : contaminated food and water.
Portal of entry: ingestion of oocyst

72. life cycle of isospora Infection by Oocyst Merozoites Undergo
Gametogony, Fertilisation oocyst
Merozoites
Undergo
Schizogony
In epithelial cell
Sporocyst Invade epithelium
Of small intestine-trophozoite
Trophozoite
Undergo
schizogony

73. ISOSPORA BELLI LIFE CYCLE

74. Clinical disease Acute infective diarrhea
Incubation period: 2 to 11 days
immunocompetant individual:
1) Rapid onset of watery diarrhea 7 to 8 stools per day
2) Nausea,anorexia,abdominal cramps
3) Low grade fever and malaise
4) Self limiting remission in 3-4 days followed by relapses from 4-7 weeks
Immuno compromised individual
1)Diarrhea is prolonged 8-7 weeks and severe.
2)Biliary diseases have been reported

76. Diagnosis-Mod acid fast staining Autofluorescence Biopsy of Intestinal mucosa PCR
20-33 um x um

77. PREVENTION WASH YOUR HANDS BEFORE YOU EAT YOUR FOOD
Wash food such as green salads and fruits, especially if it is to be eaten uncooked.
WASH YOUR HANDS BEFORE
YOU EAT YOUR FOOD
Eat meat only when it is cooked to "well done". For example, do not eat meat tartare or "rare" meat.

78. THANK YOU