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• Infective stage : oocyst

Life cycle

• Ovoidal shaped• 2 sporocyst with 4 sporozoites• Oocyst 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.