(M) Coccidia (lecture-based) part 1 Flashcards
Coccidia, C. parvum, C. hominis, C. belli, T. gondii
- Largest group of apicomplexan protozoans
- They are considered opportunistic in immunocompromised and immunodeficient
Coccidia
This is recognized as one of the major problems in animal farming and in zoo management
Coccidiosis
Eimeria
Phylum, Class, Subclass, Order, Genus
Familiarize
Apicomplexia
Conoidasida
Coccidiasina
Eucoccidiorida
Eimeria
All are true about the genera of coccidia, except:
A. Spore-forming
B. Single celled
C. Obligate intracellular parasites
D. Has an organelle of locomotion
D
rather movement is thru body flexion, gliding, or undulation of longitudinal ridges
3 phases of the life cycle
- Sporogony
- Schizogony (asexual stages)
- Gametogony phase (sexual)
Life cycle
Forms a sporoblast, that will create a wall for itself by secreting materials, , at the same time the protoplasm forms two sporozoites within the sporocyst wall
SPOROGONY/SPORULATION PHASE
Life cycle
the development of an oocyst which came from a zygote.
SPOROGONY/SPORULATION PHASE
Life cycle
TOF. Thick shelled oocysts are passed unsporulated in the feces of the host, these consist of a single nucleus in a large pool of protoplasm.
T
Life cycle
Once the sporozoites have been formed, the oocyst is an infective sporulated oocyst that is ingested by the host for the life cycle to continue.
SCHIZOGONY/MEROGONY PHASE
Life cycle
When the sporozoites have invaded an epithelial cell they become rounded and are called?
trophozoites (merogony phase)
Life cycle
This trophozoite will then divide into a number of elongated nucleated merozoites, collectively known as a?
meront (merogony phase)
Life cycle
What type of meronts is recycled in the system to infect nother small intestinal ECs
Type 1
Life cycle
This type of meront is designated to undergo the gametogony phase
Type 2
Life cycle
Phase: Ends with the production of a zygote, which begins when the merozoites, type 2, will transform into undifferentiated gamete which will undergo sexual differentation to finally become a zygote.
GAMETOGONY
- Causes diarrhea in animals (1971)
- First case in humans (1976)
- Frequent case of intractable diarrhea in immunocompromised patients
Cryptosporidium parvum
Cryptosporidium parvum
First observed in the gastric mucosal crypts of lab mice by
Tyzzer (1907)
Cryptosporidium parvum
Inhabits
small intestine, stomach, appendix, colon, rectum, biliary tree and pulmonary tree
sa module “brush borders of the mucosal epithelium of the stomach or the intestine” yan lang
Cryptosporidium parvum
Infective form
mature oocyst
Cryptosporidium parvum
causes auto infection
Thin-walled oocysts
Cryptosporidium parvum
passed out from the body through feces.
thick-walled oocysts
- Worldwide distribution.
- Common cause of diarrhea among travelers and patients of day-care centers more common among children than adults.
- It can occur as water-borne infection or zoonotic.
- In man, this parasite inhabits the brush borders of the mucosal epithelium of the stomach or the intestine. They may also inhabit the gall bladder and the pancreatic duct.
Cryptosporidium parvum
Causative agent of the disease Cryptosporidiosis
Cryptosporidium parvum
Cryptosporidium parvum
Host
Man
Cryptosporidium parvum
TOF. Heteroxenous.
F (mono)
Cryptosporidium parvum
Reservoirs
Cattle, cat, dog
Cryptosporidium parvum
Mode of Transmission
- Ingestion of contaminated food and water (water-borne is most common)
- Autoinfection
Cryptosporidium parvum
Incubation period
2-14 (7 average) days
Clinical manifestation: Biliary tract can be involved: RUQ pain, sclerosing cholangitis, cholecystitis
Cryptosporidium parvum
Clinical manifestation: chronic, persistent profuse diarrhea, weight loss, electrolyte imbalance, emaciation, and abdominal pain
Cryptosporidium parvum
- Depend on the immune status
- Immunocompetent: asymptomatic or self-limiting febrile illness with diarrhea, abdominal pain, nausea, and weight loss
- Immunocompromised: chronic, persistent profuse diarrhea, weight loss, electrolyte imbalance, emaciation, and abdominal pain
Cryptosporidium parvum
Cryptosporidium parvum
TOF. Stool can be voluminous (1 - 25 L/day).
T
Cryptosporidium parvum
Diagnosis to demonstrate colorless, spherical oocysts (4-5 um) with small and large granules
Stool Examination (DFS)
Cryptosporidium parvum
Diagnosis:
- Method of choice
- Oocysts appear as red acid-fast spheres against a blue background
Modified acid-fast stain of stool samples
Cryptosporidium parvum
May may also be done to recover the oocyst.
other than DFS and modified acid-fats stain
enterotest
Cryptosporidium parvum
What are the available serologic tests?
- Fluorescent staining: auramine-phenol or acridine orange
- Indirect IF: definitive identification
Cryptosporidium parvum
If oocysts are not demonstrable in the previous diagnosis, what can be done?
Sheather’s sugar flotation and zinc sulfate flotation can be done
Cryptosporidium parvum
Diagnosis: antibody against parasite is seen within 2 months of acute infection
Serodiagnosis
Cryptosporidium parvum
Diagnostic tool: using light and EM at the apical surface of intestinal epithelium (jejenum is preferred)
Histopathological examination
Cryptosporidium parvum
Diagnostic: lasts for 1 yr and seen using ELISA (highly sensitive and specific) or IF
Anti-oocyst ab
Cryptosporidium parvum
this diagnostic dentifies 17 kDa and 27 kDa sporozoite agn
Western blot
Cryptosporidium parvum
Self limiting typically within?
2-3 weeks
Cryptosporidium parvum
has approved for treatment of diarrhea in people with healthy immune systems, however, its effectiveness among immunosuppressed is still unclear.
Nitazoxanide
Nitazoxanide 500 mg BD x 3 day — effectiveness is still unclear
Cryptosporidium parvum
an antimicrobial used to treat a number of parasitic infections
Paromomycin
Cryptosporidium parvum
What are the Supportive management?
fluid, electrolyte and nutrient replacement
Cryptosporidium parvum
TOF. No chemotx effective.
T
di ko gets
1. Cryptosporidium parvum
TOF. Chlorination does not affect the parasite.
T
Cryptosporidium parvum
Prevention
- Synergistic effect of multiple disinfectants and combined water treatment processes may reduce C. hominis oocysts in drinking water
- Natural water and swimming pool water should not be swallowed
- Contamination of drinking water by human and animal feces should be prevented.
- Found mainly in humans
- It has a universal distribution with infections reported worldwide
- Most epidemics are associated with water usually with calf feces
- An additional species identified through genetic analysis
- All stages of development are completed in the host GI tract (monoxenous life cycle)
- It was not well recognized prior to AIDS; Nosocomial infections have been reported among health workers caring for AIDS pts
Cryptosporidium hominis
Cryptosporidium hominis
Prevelence in the Ph
2.6%
Cryptosporidium hominis
A study in San Lazaro Hospital attempted to describe Cryptosporidium among diarrheic pts and reported a prevalence of? and in PGH>
SLH = 8.5%
PGH = 1.7%
as if lalabas ‘to
Cryptosporidium hominis
Infective stage
Unsporulated oocyst
Oocysts are already infective when passed out
Should be sporulated kasi thick walled siya sa tae, mb mb
Cryptosporidium hominis
may become heavily infected and lead to acute and gangrenous cholecystitis
organs (2)
bile duct and gall bladder
- Described by Rudolf Virchow (1860) but was named only in 1923
- Was first seen in troops in the Middle East during WWI
- More common in the tropical and subtropical regions than temperate region
- The other previously known species Isospora hominis is now taxonomically grouped under Sarcocystis
Cystoisospora belli
Cystoisospora belli
Hetero or monoxenous
mono
ata
Cystoisospora belli
This parasite was described by?
Rudolf Virchow (1860)
Cystoisospora belli
TOF. Rudolf Virchow (1860) named the disease.
F (described lang)
was only named in 1923
Cystoisospora belli
host
humans
Cystoisospora belli
What takes place in vitro within 48 hours after stool passage?
sporulation
Cystoisospora belli
Diagnostic stage
recovery of unsporulated oocyst in the stool
Cystoisospora belli
Infective stage
sporulated oocyst
Cystoisospora belli
- Size: 20 - 33um x 10 - 19pm
- Shape: elongate ovoid, one end is narrowed as compared to the other that results to a “neck-like” appearance.
oocyst
Cystoisospora belli
thin smooth two-layered, colorless
Cyst wall
Cystoisospora belli
contains 1-2 sporoblasts
Immature unsporulated oocyst (diagnostic stage)
Cystoisospora belli
contains 2 sporocyst each containing 4 crescent-or banana shaped sporozoites with a single nucleus (infective stage)
Mature sporulated oocyst
Cystoisospora belli
Infection is confined to the intestinal epithelial cells, and cause destruction of the?
surface layer of the intestine
What species
There is profuse watery diarthea, malabsorption, markedly abnormal intestinal mucosa with short villi, hypertrophied crypts, and infiltration of the lamina propia with eosinophils, neutrophils, and round cells.
Cystoisospora belli
Cystoisospora belli
Causative parasite of
Human Coccidiasis.
- It has a worldwide distribution, although rare, it is more common in tropical than temperate region.
- More common in tropical and subtropical countries with poor sanitary conditions The disease is common among pts with AIDS; also reported among those with lymphoma, leukemia, and organ transplant
- Incidence:
- In Africa, 2-3% with AIDS were infected
- South America: 10%
- Haiti and Africa: 7-20%
- Endemic: Africa, Australia, Caribbean Islands, Latin America, Southeast Asia
- Incidence:
- Seen in both adults and children (day care centers and mental institutions); causes severe diarrhea among infants
- Humans are its only host; both the sexual and asexual process occurs in man.
Cystoisospora belli
Cystoisospora belli
incubation period
1-4 days
Cystoisospora belli
This produces pale yellow and foul-smelling stools that may suggest malabsorption process.
mild gastrointestinal distress to severe dysentery
Cystoisospora belli
contains undigested food, mucus, and Charcot-Leyden crystals
stool
Cystoisospora belli
(Immunocompromised/immunocompetent) self-limiting enteritis to severe diarrheal illness resembling that of cryptosporidiosis, giardiasis, or cyclosporiasis;
compromised
Cystoisospora belli
(Immunocompromised/immunocompetent) asymptomatic or self-limiting AGE
Immunocompetent
Cystoisospora belli
Poop has high fecal fat content due to
malabsorption
Cystoisospora belli
- Demonstration of the oocyst stage in fecal smears (few in numbers)
- Charcot-Leyden crystals may be seen in the specimen
- Does not contain blood and pus
Stool Examination
Cystoisospora belli
Concentration procedures
formalin-ether, ethyl acetate, zinc sulfate and sugar
Cystoisospora belli
This maybe employed to increase the yield of positive results.
Concentration procedures
Cystoisospora belli
What method produces granular red color against a green background
Modified Ziehl-Neelsen method
Cystoisospora belli
this method may reveal flattened mucosa, damaged villi, infiltration of the lamina propria with lymphocytes, plasma cells, and eosinophils
Mucosal bowel biopsy
Cystoisospora belli
TREATMENT
FAMILIARIZE NLANG PSL
- Asymptomatic infections are self-limiting and no treatment needed
- Mildly symptomatic may be managed with bed rest and bland diet
- Trimethoprim-sulfamethoxazole or Cotrimoxazole 160/800 mg QID × 10 d then BID × 21 d
- Combination therapy with pyrimethamine (50-75 mg/day) and sulfadiazine for 7 weeks
- Relapses occur in AIDS pts hence maintenance dose: TMP-SMX 1 tablet 3х a week
as if lumabas
- Worldwide distribution seen in many animal species
- Has cosmopolitan distribution and although the infection is quite common, the disease is rare.
- Endemic worldwide in humans and in domestic and wild animals
Toxoplasma gondii
Toxoplasma gondii
Causative agent of
toxoplasmosis
Toxoplasma gondii
higher prevalence of positive titers
Pigs (19%) and rats (8.1%)
Toxoplasma gondii
TOF. Available in the PH.
F (Not available in the Philippines due to lack of demand since clinical toxoplasmosis is not common)
Toxoplasma gondii
They showed that only 2.4% of the population is seropositive for Toxoplasma gondii
Cross and Basaca-Sevilla (1984)
Toxoplasma gondii
Infective stages
- Tachyzoites (in groups or clones)
- Bradyzoites (in tissue cysts)
- Sporozoites (in oocyst)
pero sa mdoule its Trophozoites, cysts and oocysts (ingested)
Toxoplasma gondii
Definitive host
Cat (complete life cycle occurs only in the cat family Felidae)
Toxoplasma gondii
Intermediate host
Man, animals, birds, rodents
Toxoplasma gondii
What stages occur in the intestinal epithelium
Schizogony, gametogony and sporogony
Toxoplasma gondii
Extraintestinal stages (asexual)
tachyzoites, bradyzoites
Toxoplasma gondii
Hetero/monoxenous
heteroxenous
Toxoplasma gondii
sporozoites enters the cell and transforms into?
tachyzoite
Toxoplasma gondii
rapidly growing trophozoites or endozoites that multiply in many types of host cell by?
endodyogeny
Toxoplasma gondii
What is this reproduction called whereby 2 daughter trophozoites are formed within the parent cell
endodyogeny
Toxoplasma gondii
In the intermediate host (man), T. gondi undergoes 2 stages of development:
ACUTE PROLIFERATIVE STAGE
CHRONIC CYSTIC STAGE
Toxoplasma gondii
STAGE: Sporozoites enter the cell and transforms into a tachyzoite, the rapidly growing trophozoites or endozoites that multiply in many types of host cell by ENDODYOGENY (is a form of asexual reproduction that involves the development of two daughter cells within a mother cell, which is consumed by the offspring upon their maturation).
ACUTE PROLIFERATIVE STAGE.
Toxoplasma gondii
STAGE: As host immunity develops antibodies, the fast multiplying tachyzoites give rise to slow multiplying bradyzoites that form cysts which are found in visceral organs, including the lungs, liver, and kidneys but are more prevalent in the neural and muscular tissues, including the brain, eyes, and skeletal and cardiac muscles.
CHRONIC CYSTIC STAGE
Toxoplasma gondii
Through what host is where ingestion of cysts that leads to a stage of endodyogeny.
definitive host (cat)
Toxoplasma gondii
Endodyogeny is immediately followed by a stage of repeated ?
endopolygeny
Toxoplasma gondii
this is an asexual reproduction in which several, more than two daughter cells are formed within a mother cell via internal budding, in the cat small intestine epithelial cells, producing merozoites
endopolygeny
Toxoplasma gondii
Merozoites multiply (schizogony stage) and some undergo gametogenesis resulting to production of?
micro- and macrogametocytes (gametogony/gamogony)
Toxoplasma gondii
Fertilization of the macrogamete results to the formation of?
unsporulated oocysts
then expelled in the feces of the definitive host to the external environment.
Toxoplasma gondii
In the environment, sporulation of the oocyts occurs and completed within how many days?
3-4 days
T. gondii
are present in humans and other intermediate hosts. Schizogony and sporogony both occur in cat.
tachyzoites and bradyzoites
T. gondii
TOF. Endodyogeny in the definitive host, while endodyogeny, endopolydeny and gamogony in the intermediate host.
F (opposite)
Endodyogeny - intermediate - man
Endodyogeny, endopolygeny gamogony - definitive - cat
T. gondii
- are rapidly dividing trophozoites seen during the acute phase of the infection.
- Crescent shaped, approximately 2 by 6 um, with a pointed anterior (conoidal) end and a rounded posterior end.
- Spherical to ovoid nucleus that is usually nearer the blunt end.
TACHYZOITES
T. gondii
are the slow multiplying forms within the cyst during the chronic cystic phase of the infection
BRADYZOITES/CYSTOZOITES
T. gondii
Transmission
Horizontal and vertical transmission
T. gondii
Transmission: via pocyts (consuming food or water contaminated with mature oocysts shed into the environment by cats feces, eating undercooked meat of animals harboring tissue cysts containing tachy/bradyzoites
Horizontal
T. gondii
Transmission: via tissue cysts (Blood transfusion, organ/BM transplantation)
Horizontal
T. gondii
transmission: via oocysts (Transplacental transfer from the mother to the fetus during pregnancy
Vertical transmission
T. gondii
Incubation period
2-14 days
T. gondii
TOF. Most cases are asymptomatic; only manifests as a disease in immunodeficiency or suppression.
T
T. gondii
often severe and even fatal manifesting with the so-called Sabin syndrome, which consists of chorioretinitis, cerebral calcification, convulsion or psychomotor disturbance, and hydrocephalus or microcephalus.
Congenital toxoplasmosis
T. gondii
may result in mothers acquiring the infection during first trimester
Stillbirth and abortion
T. gondii
the most common form of the disease.
Acquired toxoplasmosis
T. gondii
the most common type, resembles infectious mononucleosis, characterized by cervical and axillary lymphadenopathies, malaise, muscle pain, and irregular low-grade fever
mild lymphatic form of Acquired toxoplasmosis
T. gondii
often with skin rashes, chills, high grade fever, and prostration which may be associated with encephalitis, myocarditis and focal pneumonia, retinochoroiditis, hepatitis, splenomegaly, extramedullary hematopoiesis, failure to gain weight
Acute fulminating disseminated infection of Acquired toxoplasmosis
T. gondii
diagnostic diagnosis
Biopsy of lymph nodes, bone marrow, spleen, brain and other tissues to demonstrate the organisms
T. gondii
DIAGNOSIS
familiarize
- Demonstration of the oocyst in fecal smear.
- Biopsy of lymph nodes, bone marrow, spleen, brain and other tissues to demonstrate the organisms (tissue cyst) is diagnostic.
- Serologic tests are used to detect antibodies:
- Complement Fixation test, Double Sandwich ELISA test, Indirect Immunofluorescent antibody test., Indirect Hemagglutination test, Sabin-Feldman dye test, and Frenkel skin test, which is a type of delayed hypersensitivity reaction.
- A seroconversion to a positive titer of 4-fold increase is indicative of an infection
- High titers (>1,024) may also be seen in chronic cases hence the need for IgM antibody detection via IgM indirect fluorescent ab technique or a sandwich ELISA
- Polymerase Chain Reaction for detection of the parasites
- DNA can be used in serum, amniotic fluid, CSF and brochioalveolar lavage
T. gondii
Persons who are ill and immunocompromised can be treated with:
Pyrimethamine 25-100 mg OD and Sulfadiazine 1-1.5 g QID in combination for 1 month (can keep Toxoplasma under control but do not kill it)
T. gondii
Pyritethamine can lower blood counts in most people. It should be given with?
Leucovorin (folinic acid)
T. gondii
may cause serious allergic actions (fever, rash)
Can be substituted with Clindamycin, Azithromycin, Clarithromycin, Dapsone, Atovaquone
Sulfadiazine
T. gondii
used to prevent hypersensitivity reactions
steroids
T. gondii
treatment for for immunocompromised
Prophylaxis with TMP/SMX
