Giardiasis. Functional, immunological and histological study of the small bowel. Therapeutic trial with a single dose of tinidazole.

Fourteen patients between the ages of 9 months and 5 years with chronic diarrhea and giardiasis were studied. Ten were eutrophic and 4 undernourished. The parasitological diagnosis was based on stool examination, a trophozoite search in duodenal aspiration, mucus adhered to mucosa and parasite identification in the intestinal biopsy material. Functional intestinal absorption studies, IgA determination in intestinal secretions and immunofluorescence studies were made. After the tests, tinidazole in suspension was administered at 60-70 mg/kg in one single oral dose. Patients were clinically re-evaluated and tests were done again after 30 days. The purpose of this paper was to evaluate the changes in the functional morphologic and immunologic studies and the therapeutic efficacy of the drug in a single dose. Nine patients had good clinical results, 2 fair and 3 were not evaluated due to celiac disease. All had negative results on the parasitological tests after treatment. There was no relationship between the number of parasites and the severity of symptoms. There was no significant difference between stool fat and d-xylose at the time of diagnosis and 30 days after the administration of tinidazole. The lactose tolerance test presented a significant difference (p less than 0.05) in the disaccharide absorption after treatment. The secretory IgA revealed significantly lower value (p less than 0.01) with respect to the normal values. The immunofluorescence showed productive IgA cells in all cases. The histologic changes were: mild enteropathy (grade I) in 6 patients; moderate (grade II) in 5; and severe (grade III-IV) in 3. Improvement of the mucosa was seen in 6 patients.