Stool samples examination Parasitological diagnosis will be performed by triple coproscopy using formalin - ethyl acetate concentration technique. For preparations staining Lugol's solution was used. The intensity of protozoa will be estimated by the number of protozoa in the field of view (ocular x10, objective x40), the number of protozoa will be calculated at least in 10 fields of view. 1-2, 3-4 and 5-6 microorganisms in a field of view were considered as infection of low, mean and high intensity respectively.