Parasitology (apicomplexa)

contains Apicomplexa ( Sporozoa),
CRYPTOSPORIDIUM �PARVUM
CYLOSPORA CAYETONENSIS, Sarcocystis spp. and
MICROSPORIDIA

1. PARASITOLOGY
(apicomplexa)

2. Apicomplexa ( Sporozoa)
-all apicomplexans are obligate intracellular parasites
and have an apical complex.
-elongated shape
APICAL COMPLEX
micronemes
Rhoptries
Polar rings
-apicomplexans replicate via schizogony.

3. 3 Distinct processes of Apicomplexan Life
Cycle
Sporogony-asexual reproductive phase
Gamogony/gametogony-sexual phase
Female gametes+ Male gametes=
ookinete/sporoblast
Merogony-asexual reproduction; cellular
products are called merozoites.

5. Diseases cause by
Apicomplexan Organism
Babesiosis
Malaria
Forms of cocciodiosis including
-Cryptosporidiosis
-Cyclosporiasis
-Isosporiasis
-Toxoplasmosis

6. CRYPTOSPORIDIUM
PARVUM

7. Cryptosporidium parvumis a
protozoan and an obligate intracellular
parasite(a parasite that cannot survive
without a host) that commonly causes
an opportunistic infection in
immunocompromised hosts.
C. parvum is considered to be the most
important waterborne pathogen in
developed countries.

8. Disease cause by C.parvum
•Cryptosporidiosis (krip-to-spo-rid-e-O-
sis), is a diarrheal disease caused by
microscopic parasites, Cryptosporidium,
that can live in the intestine of humans and
animals and is passed in the stool of an
infected person or animal. Both the
disease and the parasite are commonly
known as "Crypto"..

9. Morphology
Oocysts
•Size: 4-6 μm.
•Morphology: round,
oval
•They are mainly
located in the jejunum.

10. Life cyle

11. •Crypto begins its life cycle as sporulated
oocysts (1) which enter the environment
through the feces of the infected host.
•The infective oocysts reside in food and
water (2).
•Infection occurs when the oocysts are
ingested by a suitable host (3)
Life Cycle

12. Swallowing pool water that has been contaminated
with the parasite
In contaminated food or drink (called heteroinfection).
By faeco-oral route (hand to mouth) in already
infected patient ( called external autoinfection).
by touching your mouth after touching the
stool of infected persons or animals or touching soil or
objects contaminated with stool.
Mode of transmission

13. •Increased intestinal secretion of sodium
and chloride, water absorption is inhibited
•Epithelial cells damaged by:
•Parasite invasion and multiplication
•May produce up to 10-20 liters of watery
stools per day
Pathogenesis

14. •The first signs and symptoms of
cryptosporidium infection usually appear
within a week after infection and may
include:
•Watery diarrhea
•Dehydration
•Lack of appetite
•Weight loss
Symptoms

15. Stomach cramps or pain
Fever
Nausea
Vomiting
Symptoms may last for up to: 1-14 days,
though they may come and go
sporadically for up to a month, even in
people with healthy immune systems.
Some people with cryptosporidium
infection may have no symptoms

16. TREATMENT
•paromomycin, may reduce the symptoms
of crypto
•drink plenty of fluids.
•Nitazoxanide has been FDA-approved for
treatment of diarrhea caused by
Cryptosporidium

17. Treatment
HIV-positive individuals who suspect they
have cryptosporidiosis should contact their
health care provider. For those persons
with AIDS, anti-retroviral therapy that
improves the immune status will also
decrease or eliminate symptoms of
cryptosporidiosis. However, even if
symptoms disappear, cryptosporidiosis is
often not curable and the symptoms may
return if the immune status worsens.

18. Prevention
1.The easiest way to prevent cryptosporidiosis is
to practice good hygiene, especially after using
the toilet.. b. After handling animals
2.After touching dirt
3.Before preparing food
4.Avoid drinking untreated water
5.Peel and rinse fruits and vegetables
6.Follow water advisories
7.Boiling and microfiltration of drinking water

19. CYLOSPORA CAYETONENSIS

20. General Characteristics
•is anapicomplexan, cyst-
formingcoccidianprotozoanthat causes
a self-limiting diarrhea
•unicellular parasite that causes an
intestinal infection called cyclosporiasis.
•Acid-fast variable,have been found in
the feces of immunocompetent
travellers.
Pathogenic

21. Morphology
•has sphericaloocyststhat are between 7.5
and 10micrometersin diameter.
•a 50-nanometer-thick wall with an outer
threadlike coat called a wrinkle

22. •By drinking water or eating food that's been
contaminated by an infected person.
•type of sanitation and contact with soil
•direct person to person transmission
•through the fecal-oral
•visiting regions where the species is
endemic.
Mode of Transmission:

23. Life Cycle

24. Sign and Symptoms
•Nausea
•Vomiting
•Muscle aches
•Low-grade fever
•Fatigue
•General feeling of
unwellness
•Burping
•Stomach cramps
•Watery diarrhea
•Frequent and
sometimes
explosive bowel
movements
•Bouts of diarrhea
alternating with
bouts of constipation
•Loss of appetite

25. 25
Prevention
•The simplest one is to warn travelers
not to visit regions where the protozoan
is endemic.
•Individuals in endemic areas should
wear gloves when gardening to prevent
exposure to oocysts.
•Thorough washing may help remove
oocysts.

26. Therapy
•Patients have been treated symptomically
with antidiarrheal preparations and have
obtained some relief;
•Trimethoprin(TMP-SMX)
•orally twice daily for seven days.
Elimination of parasites a decrease in
diarrhea.
diminished abdominal pain occur
within 2-3 days after treatment.
•Patients with AIDS needs higher dose and
long term

27. Sarcocystis
spp.

28. Sarcocystis spp.
General Characteristics:
-Two well described Sarcocystis spp.include
S. bovihominis(cattle) and S. suihominis (pig).
When uncooked meat from this infected
animals ingested by humans,
gamogony(fission resulting in the production
sporozoan gametes) can occur in the
intestinal cells, with eventual production
sporocysts in stool.

29. -Sarcocystis spp. Have an obligatory 2
hosts life cycle.
Intermediate host(herbivores and
omnivores)-infected through ingestion
of sporocysts secrete in the feces of the
definitive host.
Definitive host (carnivores and
omnivores)-Human who have ingested
meat containing the mature sarcocysts
serve as the definitive host.

30. For immunocompromised hosts:
-fever
-sever diarrhea
-abdominal pain
-weight loss.
-Sporocysts found in the stool are broadly
oval and slightly tapered at the ends.
-9-16 um long

31. Pathogenesis and Spectrum of Disease
-when human ingests oocysts from other
animal stool sources, the sarcocysts that
develop in human muscle are 7-16 um long
and cause few problems. Basically, no
inflammatory response, no evidence of
pathogenicity is seen.
CORTICOSTEROIDs -reduce allergic
inflammatory reactions.

32. Ingestion of Infected meat manifests
primarily intestinal disease within few
hours after consumption, characterized
by;
Nausea
Abdominal pain
Diarrhea
However, patients may be
asymptomatic.

33. Prevention
Cooking meat to an internal temperature higher than
67degree kills taxoplasma gondii tissue cysts in meat.
Preventing cattle, buffalos, and swine from
consuming human feces shedding infective oocysts
also prevents animal infection.
When human are intermediate hosts, preventive
measures involve careful disposal of animal feces
that may contain the infective sporocysts.

34. Treatment
•no known treatment or prophylaxis is
available for intestinal infection, myositis,
vasculitis, or related lesions caused by
human sarcocystosis.
•Supportive therapy for patients with
severe diarrhea is indicated.

35. MICROSPORIDIA

36. MiCROSPORIDIA
=intracellular spore -forming parasites;
=clinical manifestations of
microsporidiosis include intestinal,
pulmonary, ocular, muscular, and renal
disease. Microsporidiosis has been
identified in immunosuppressed
hosts ,travelers, children, and the elderly.
=shared the same features with fungi

37. Morphology
-spores are all round and oblong, and those
associated with human infection tend to be
about 1-4 um size.

38. THE LIFE CYCLE

39. Transmission:
•human-to-human
•animal-to-human
•water transmission
•inhalation or ingestion

40. DIAGNOSTIC TESTS
Fecalysis
Urinalysis
Other body fluid or tissues
Transmission electron microscopy-gold
standard for identifying specific spp.

41. PREVENTION
•NO vaccine available
•Filtrating water supply
•Taking precaution when handling body
fluids
•Improving personal hygiene(e.g
handwashing)

42. THERAPY,TREATMENT
Albendazole-Gastro, muscle,
disseminated and ocular infections.
Metronidazole-E. bieneusi and others.
Fumagillin-Keratoconjunctivitis and ocular
lesions (Encephalitozoon spp. B. algarae, E.
hellum, E. cuniculi, V. corneae); Not
approved by FDA for microsporidiosis.