GASTRO-INTESTINAL TRACT

ORDO COCCIDIA:– Cryptosporidium– Cyclospora– Isospora

Cryptosporidium parvum• Cosmopolite, causing cryptosporidiosis• recognized as one of the most common

causes of waterborne disease • Found in human and animals• Prevalence: especially in children ( Brazil :

90 % < 5 years age)• Incidens: >> in AIDS patients (12-48% )

Life cycle• Size: 4- 5 µ • spherical• Habitat : cell

membrane of epithel of all parts of GI tract

• Sporogony produce 2 kinds of oocyst:–Thick wall oocyst, released and

comes out with feces–Thin wall oocyst, excysted in the

lumen auto-infection

Pathogenesis & Clinical symptoms• Infection: swallowing contaminated

drinking water or recreational water ( swimming pools, hot tubs, fountains, lakes, rivers) containing oocyst

• Incubation period: 2-10 days ( average 7 days)

• Watery diarrhea, no blood and mucous• nausea, vomiting, anorexia

Clinical symptoms (cont’d)• In immunocompetent person: self

limited • In immuno compromised :

–Cholera- like diarrhea dehydration– can be found in respiratory tract and

hepato-biliary system

Diagnosis• Detection of oocyst in the feces• Difficult to differentiate with yeast cell in

direct examination using different techniques (e.g., acid-fast staining, direct fluorescent antibody)

• Molecular methods :PCR

Epidemiology• Animals could become a source of infection• Prevention:

–Wash hands with soap and water for at least 20 seconds, after contact with animal, gardening

–All fruits and vegetables you plan to eat raw should be thoroughly washed with uncontaminated water.

Prevention

• Drink only boiled water• Oocyst resistant to chlorine

Source: CDC

Cyclospora cayetanensis• causing cyclosporiasis• Cosmopolite, >> in developing

countries• most common in tropical and

subtropical areas• Persons of all ages are at risk for

infection (>> children)• Cyclospora infects the small intestine

Life Cycle

The oocysts are require days to weeks in favorable environmental conditions to sporulate

Clinical symptoms

• watery diarrhea, which can be severe. • anorexia, weight loss, abdominal pain,• nausea and vomiting,• myalgias, low-grade fever, and

fatigue. 

Diagnosis• identification of oocysts in stool specimens

by light microscopy• Stained smears: using modified acid fast

stain

Epidemiology

• commonly occurred in persons who traveled (traveler’s diarrhea)

• chlorine or iodine is unlikely to kill Cyclospora oocysts.

• Prevention: avoiding food or water that may have been contaminated with feces

Isospora belli/ Isospora hominis(Cystoisosporiasis)

• Causing : isosporiasis / cystoisosporiasis• Rarely found in human• Incidens increased in AIDS patients• Bentuk infektif : ookista

Life cycle

Bentuk lonjong 2 sporocyst with 4 sporozoitesOocyst will be mature within 1 – 5 days

• Clinical symptoms: diarrhea• In immuno competent : mild infection

and self lilmited• In the severe cases need therapy• In immuno compromised need longer

treatment

Epidemiology• self limiting disease• Avoiding food or water that might be

contaminated with stool may help prevent infection.

• good handwashing• personal-hygiene practices should be

followed.