(M) Coccidia (lecture-based) part 1 Flashcards by ASHLEY JARED DEFENSOR

Largest group of apicomplexan protozoans
They are considered opportunistic in immunocompromised and immunodeficient

Coccidia

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This is recognized as one of the major problems in animal farming and in zoo management

Coccidiosis

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Eimeria

Phylum, Class, Subclass, Order, Genus

Familiarize

Apicomplexia
Conoidasida
Coccidiasina
Eucoccidiorida
Eimeria

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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

rather movement is thru body flexion, gliding, or undulation of longitudinal ridges

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3 phases of the life cycle

Sporogony
Schizogony (asexual stages)
Gametogony phase (sexual)

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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

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Life cycle

the development of an oocyst which came from a zygote.

SPOROGONY/SPORULATION PHASE

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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.

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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

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Life cycle

When the sporozoites have invaded an epithelial cell they become rounded and are called?

trophozoites (merogony phase)

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Life cycle

This trophozoite will then divide into a number of elongated nucleated merozoites, collectively known as a?

meront (merogony phase)

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Life cycle

What type of meronts is recycled in the system to infect nother small intestinal ECs

Type 1

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Life cycle

This type of meront is designated to undergo the gametogony phase

Type 2

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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

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Causes diarrhea in animals (1971)
First case in humans (1976)
Frequent case of intractable diarrhea in immunocompromised patients

Cryptosporidium parvum

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Cryptosporidium parvum

First observed in the gastric mucosal crypts of lab mice by

Tyzzer (1907)

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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

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Cryptosporidium parvum

Infective form

mature oocyst

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Cryptosporidium parvum

causes auto infection

Thin-walled oocysts

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Cryptosporidium parvum

passed out from the body through feces.

thick-walled oocysts

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- 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

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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).

# 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 ## Footnote 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 ## Footnote di ko gets

# 1. Cryptosporidium parvum TOF. Chlorination does not affect the parasite.

# 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% ## Footnote as if lalabas 'to

# Cryptosporidium hominis Infective stage

Unsporulated oocyst ## Footnote 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 ## Footnote ata

# Cystoisospora belli This parasite was described by?

Rudolf Virchow (1860)

# Cystoisospora belli TOF. Rudolf Virchow (1860) named the disease.

F (described lang) ## Footnote 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 - 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 ## Footnote 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) ## Footnote 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 ## Footnote 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. 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 ## Footnote 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

(M) Coccidia (lecture-based) part 1 Flashcards

Coccidia, C. parvum, C. hominis, C. belli, T. gondii