Background: Up to now there have been few reports about hematological alterations induced by Giardia lamblia infection. The aim of this study was to evaluate the effects of giardiasis treatment on hematological indices in children in the Khuzestan area by comparing these indices before and after treatment with metronidazole.
Material/Methods: One hundred two children ranging in age from 5 to 11 years infected with Giardia lamblia between July 2002 and July 2003 and without histories of other diseases were selected from kindergartens and primary schools in the city of Ahwaz. Diagnosis was based on stool examination. The children were treated with metronidazole (15 mg/kg/day for 5 days); hematological values were determined immediately before treatment and repeated 40-45 days after beginning treatment and compared.
Results: Iron deficiency anemia was found in 26.5% of the Giardia-infected children. Mean serum hemoglobin, serum hematocrit, serum ferritin, and the ratio of serum iron to total iron-binding capacity were increased (P<0.0001) and mean red-cell distribution width and iron-binding capacity were decreased after treatment (P<0.0001).
Conclusions: Treating giardiasis in children with metronidazole improves iron indices and it appears that in evaluating anemia one should rule out giardiasis and treat it in asymptomatic cases to aid in better health status in pediatrics.

Keywords: Erythrocyte Indices, Antiprotozoal Agents - therapeutic use, Anemia, Iron-Deficiency - etiology, Child, Preschool, Child, Ferritins - blood, Giardiasis - drug therapy, Iran, Iron - blood, Metronidazole - therapeutic use