Morphology and frequency distribution of protozoan Blastocystis hominis.

Eight hundred stool specimens were examined for the presence of Blastocystis Hominis (BH) by direct microscopy in Saline and Iodine and by concentration with formal saline ether method. Four hundred specimens were positive for Cyst or Ova of various parasites, of which BH was present in 12% samples. Of the total 400 positive cases 56% were positive for Protozoa and within this group 21% were positive for BH. Morphologically these protozoa were seen as organelles 8 lOu in size with cytoplasm compressed at the periphery of the cell by a large central vacoule. Often similar organelles of size lO-60u were also seen. Fourteen cases who presented with diarrhoea and had high concentrations of this parasite were treated with Di-iodoquin or Metronidazole. The treatment lead to disappearance of parasites from faeces and cesation of diarrhoea (JPMA 38: 322, 1988).