Comparison of parasitological techniques for the diagnosis of intestinal parasitic infections in patients with presumptive malabsorption.

Intestinal parasitic infections still remain a public health problem, overall in tropical and subtropical regions. Frequently, patients with malabsorption syndrome can be infected with intestinal parasites, independent that they could be the etiological agents. To compare three coproparasitological techniques Paratest, Ritchie and direct wet mount for the diagnosis of intestinal parasitic infections in patients with suspected malabsorption syndrome. A descriptive cross sectional survey was carried out in 82 patients with presumptive symptoms of intestinal malabsorption. Three consecutive stool samples were collected from every patient and they were analyzed by three coproparasitological techniques. The degree of agreement was almost perfect when all parasitological techniques were compared for all protozoan infections. Nevertheless, the agreement between Paratest and Ritchie's methods was slightly lower because this last method was superior for intestinal infections with commensals. The technique of Ritchie showed 100% of sensitivity for protozoa infections in general. However, the direct wet mount and the Paratest, showed lower sensitivity. When all techniques were compared only for infections with no pathogenic protozoa, the Paratest had the lowest sensitivity, and less predictive value for negatives. Ritchie's method showed a higher superiority than Paratest for the diagnosis of intestinal protozoa infections in this group of patients. We would recommend the evaluation of new techniques in local conditions before to decide the introduction in the public health network of laboratories.