through examining a stool sample under a microscope. The diagnostic stage is the immature oocyst that contains a spherical mass of protoplasm. In other words, the oocyst that is diagnosed in the stool sample is unsporulated, and contains only one sporoblast. For stool diagnosis, direct smear, concentration smear, microscopic wet mount, or iodine stains of fecal smears are adequate. But for easy screening, acid-fast stains is recommended. If stool test is negative, and biopsies of the small intestine is performed, different stages of schizogony and sporogony should exist in the epithelial cells, but the alteration of the villi is not necessarily present. Eosinophilia may also be seen unlike in the case of other protozoal infections. This infection is easily treated with antibiotics. The most common antibiotic that is prescribed is co-trimoxazole (trimethoprimsulfamethoxazole), more commonly known as Bactrim, Septra, or Cotrim. In AIDS patients, treatments can result in the disappearance of the symptoms, but recurrence of symptoms is common. In order prevent the recurrence, medication is continued in AIDS patients and other immunosuppressed patients. Transmission and prevention Cystoisospora belli does not require an intermediate host and currently is only known to transmit from person to person. The method of transmission is ingesting food or water that has been contaminated with feces from someone who is infected. Washing your hands with soap and warm water after using the toilet, changing diapers, and before handling food is vital. Also, educating children the importance of hand-washing and good hygiene practice is important. Because HIV-AIDS patients will have higher risk of symptomatic intestinal parasitic infections, and pathogenic burden can increase disease progression and contributes to early death, routine screening of parasites especially in patients with lower CD4 count should be emphasized. History Isospora belli was discovered by Rudolf Virchow in 1860 and was named by Charles Morley Wenyon in 1923. The parasite is now known as Cystoisospora belli. References Conoidasida