
Intestinal coccidian infection is a major health problem in a developing country like India, having the largest number of people living with HIV in the world. This study includes 80 stool samples from AIDS patients with diarrhoea attending St. John medical college and hospital, Bangalore. Cryptosporidium species and Isospora species oocysts were detected using modified acid fast stain and rapid saffranin method. This was done in stool samples before and after concentration. Cryptosporidium species oocyst (2.5%) was detected in the stool samples stain with modified acid fast stain before stool concentration. An additional Cryptosporidium species oocyst (18.75%) was detected following stool concentration. Isospora species oocyst (11.25%) was detected following formalin ether concentration technique. Of the Cryptosporidium oocyst (3.7%) detected by the modified acid fast stain was also seen using the rapid saffranin method following stool concentration method. Cyclospora oocysts were not detected. Both modified acid fast stain and rapid saffranin method are useful in demonstrating oocysts of Cryptosporidium species and Isospora species. Stool concentration improved detection of oocysts.